Abstract The exposure of organisms and cells to unfavorable conditions such as increased temperature, antibiotics, reactive oxygen species, and viruses could lead to protein misfolding and cell death. The increased production of proteins such as heat shock proteins (HSPs) and polyamines has been linked to protein misfolding sequestration, thus maintaining, enhancing, and regulating the cellular system. For example, heat shock protein 40 (Hsp40) works hand in hand with Hsp70 and Hsp90 to successfully assist the newly synthesized proteins in folding properly. On the other hand, polyamines such as putrescine, spermidine, and spermine have been widely studied and reported to keep cells viable under harsh conditions, which are also involved in cell proliferation, differentiation, and growth. Polyamines are found in all living organisms, including humans and viruses. Some organisms have developed a mechanism to hijack mammalian host cell machinery for their benefit like viruses need polyamines for infection. Therefore, the role of HSPs and polyamines in SARS-CoV-2 (COVID-19) viral infection, how these molecules could delay the effectiveness of the current treatment in the market, and how COVID-19 relies on the host molecules for its successful infection are reviewed.
{"title":"The capture of host cell’s resources: The role of heat shock proteins and polyamines in SARS-COV-2 (COVID-19) pathway to viral infection","authors":"X. Makhoba, S. Makumire","doi":"10.1515/bmc-2022-0008","DOIUrl":"https://doi.org/10.1515/bmc-2022-0008","url":null,"abstract":"Abstract The exposure of organisms and cells to unfavorable conditions such as increased temperature, antibiotics, reactive oxygen species, and viruses could lead to protein misfolding and cell death. The increased production of proteins such as heat shock proteins (HSPs) and polyamines has been linked to protein misfolding sequestration, thus maintaining, enhancing, and regulating the cellular system. For example, heat shock protein 40 (Hsp40) works hand in hand with Hsp70 and Hsp90 to successfully assist the newly synthesized proteins in folding properly. On the other hand, polyamines such as putrescine, spermidine, and spermine have been widely studied and reported to keep cells viable under harsh conditions, which are also involved in cell proliferation, differentiation, and growth. Polyamines are found in all living organisms, including humans and viruses. Some organisms have developed a mechanism to hijack mammalian host cell machinery for their benefit like viruses need polyamines for infection. Therefore, the role of HSPs and polyamines in SARS-CoV-2 (COVID-19) viral infection, how these molecules could delay the effectiveness of the current treatment in the market, and how COVID-19 relies on the host molecules for its successful infection are reviewed.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"220 - 229"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47479910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Gatta, V. Bazzurro, E. Angeli, A. Salis, G. Damonte, A. Cupello, M. Robello, A. Diaspro
Abstract The study of the GABAA receptor itself and its pharmacology is of paramount importance for shedding light on the role of this receptor in the central nervous system. Caged compounds have emerged as powerful tools to support research in this field, as they allow to control, in space and time, the release of neurotransmitters enabling, for example, to map receptors’ distribution and dynamics. Here we focus on γ-aminobutyric acid (GABA)-caged compounds, particularly on a commercial complex called RuBi-GABA, which has high efficiency of uncaging upon irradiation at visible wavelengths. We characterized, by electrophysiological measurements, the effects of RuBi-GABA on GABAA receptors of rat cerebellar granule cells in vitro. In particular, we evaluated the effects of side products obtained after RuBi-GABA photolysis. For this purpose, we developed a procedure to separate the “RuBi-cage” from GABA after uncaging RuBi-GABA with a laser source; then, we compared electrophysiological measurements acquired with and without administering the RuBi-cage in the perfusing bath. In conclusion, to investigate the role of the “cage” molecules both near and far from the cell soma, we compared experiments performed changing the distance of the uncaging point from the cell.
{"title":"Electrophysiological study of the effects of side products of RuBi-GABA uncaging on GABAA receptors in cerebellar granule cells","authors":"E. Gatta, V. Bazzurro, E. Angeli, A. Salis, G. Damonte, A. Cupello, M. Robello, A. Diaspro","doi":"10.1515/bmc-2022-0022","DOIUrl":"https://doi.org/10.1515/bmc-2022-0022","url":null,"abstract":"Abstract The study of the GABAA receptor itself and its pharmacology is of paramount importance for shedding light on the role of this receptor in the central nervous system. Caged compounds have emerged as powerful tools to support research in this field, as they allow to control, in space and time, the release of neurotransmitters enabling, for example, to map receptors’ distribution and dynamics. Here we focus on γ-aminobutyric acid (GABA)-caged compounds, particularly on a commercial complex called RuBi-GABA, which has high efficiency of uncaging upon irradiation at visible wavelengths. We characterized, by electrophysiological measurements, the effects of RuBi-GABA on GABAA receptors of rat cerebellar granule cells in vitro. In particular, we evaluated the effects of side products obtained after RuBi-GABA photolysis. For this purpose, we developed a procedure to separate the “RuBi-cage” from GABA after uncaging RuBi-GABA with a laser source; then, we compared electrophysiological measurements acquired with and without administering the RuBi-cage in the perfusing bath. In conclusion, to investigate the role of the “cage” molecules both near and far from the cell soma, we compared experiments performed changing the distance of the uncaging point from the cell.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"289 - 297"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47072426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Koudpoko Madeleine Kabre, Djénéba Ouermi, Théodora Mahoukèdè Zohoncon, Fatié Porzé Wilfried Traore, Ouamini Pulchérie De Prisca Gnoumou, Rogomenoma Alice Ouedraogo, Albert Théophane Yonli, Prosper Bado, Paul Ouedraogo, Teega-Wendé Clarisse Ouedraogo, Tampoula Edwige Yelemkoure, Punya Akouélé Kuassi-Kpede, Dorcas Obiri-Yeboah, Charlemagne Marie Ragnag-Néwendé Ouedraogo, Jacques Simpore
Introduction: Genital human papillomavirus (HPV) infection is widespread among sexually active individuals. Several factors may contribute to increased risk of infection in pregnant women. The objective of this study was to determine the high-risk (HR-HPV) and low-risk (LR-HPV) oncogenic HPV genotypes among pregnant women in Ouagadougou.
Methodology: In this study, 100 endocervical samples were collected using a sterile swab on the sterile examination glove used during vaginal examination in pregnant women. DNA from each sample was amplified by PCR followed by hybridization using the HPV Direct Flow Chips kit detecting 36 HPV genotypes.
Results: Twenty-three percent (23%) of pregnant women had HPV infection. Of the 36 genotypes tested, 29 genotypes had been identified with a predominance of HPV 52 (10.34%), HPV 35 (6.89%), and HPV 82 (6.89%) for high risk and HPV 43 (10.34%), HPV 44/55 (6.90%), and HPV 62/81 (6.89%) for low risk.
Conclusion: HPV is common among pregnant women in Burkina Faso. However, the available vaccines do not cover the frequent genotypes found in this study. HPV could therefore constitute a threat for pregnant women and a risk of infection for the newborn.
简介:生殖器人乳头瘤病毒(HPV)感染在性活跃的个体中广泛存在。有几个因素可能导致孕妇感染风险增加。本研究的目的是确定瓦加杜古孕妇中高危(HR-HPV)和低危(LR-HPV)致癌HPV基因型。方法:在本研究中，使用无菌棉签在孕妇阴道检查时使用的无菌检查手套上收集了100份宫颈内样本。每个样本的DNA通过PCR扩增，然后使用HPV Direct Flow Chips试剂盒检测36种HPV基因型进行杂交。结果:23%的孕妇有HPV感染。在检测的36个基因型中，29个基因型中高危型以HPV 52(10.34%)、HPV 35(6.89%)和HPV 82(6.89%)为主，低危型以HPV 43(10.34%)、HPV 44/55(6.90%)和HPV 62/81(6.89%)为主。结论:HPV在布基纳法索孕妇中很常见。然而，现有的疫苗不包括本研究中发现的常见基因型。因此，人乳头瘤病毒可能对孕妇构成威胁，并有感染新生儿的风险。
{"title":"Molecular epidemiology of human papillomavirus in pregnant women in Burkina Faso.","authors":"Koudpoko Madeleine Kabre, Djénéba Ouermi, Théodora Mahoukèdè Zohoncon, Fatié Porzé Wilfried Traore, Ouamini Pulchérie De Prisca Gnoumou, Rogomenoma Alice Ouedraogo, Albert Théophane Yonli, Prosper Bado, Paul Ouedraogo, Teega-Wendé Clarisse Ouedraogo, Tampoula Edwige Yelemkoure, Punya Akouélé Kuassi-Kpede, Dorcas Obiri-Yeboah, Charlemagne Marie Ragnag-Néwendé Ouedraogo, Jacques Simpore","doi":"10.1515/bmc-2022-0026","DOIUrl":"https://doi.org/10.1515/bmc-2022-0026","url":null,"abstract":"<p><strong>Introduction: </strong>Genital human papillomavirus (HPV) infection is widespread among sexually active individuals. Several factors may contribute to increased risk of infection in pregnant women. The objective of this study was to determine the high-risk (HR-HPV) and low-risk (LR-HPV) oncogenic HPV genotypes among pregnant women in Ouagadougou.</p><p><strong>Methodology: </strong>In this study, 100 endocervical samples were collected using a sterile swab on the sterile examination glove used during vaginal examination in pregnant women. DNA from each sample was amplified by PCR followed by hybridization using the HPV Direct Flow Chips kit detecting 36 HPV genotypes.</p><p><strong>Results: </strong>Twenty-three percent (23%) of pregnant women had HPV infection. Of the 36 genotypes tested, 29 genotypes had been identified with a predominance of HPV 52 (10.34%), HPV 35 (6.89%), and HPV 82 (6.89%) for high risk and HPV 43 (10.34%), HPV 44/55 (6.90%), and HPV 62/81 (6.89%) for low risk.</p><p><strong>Conclusion: </strong>HPV is common among pregnant women in Burkina Faso. However, the available vaccines do not cover the frequent genotypes found in this study. HPV could therefore constitute a threat for pregnant women and a risk of infection for the newborn.</p>","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"334-340"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10647724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Marini, M. Bouzin, R. Scodellaro, L. D’alfonso, L. Sironi, F. Granucci, F. Mingozzi, G. Chirico, M. Collini
Abstract Super-resolution image acquisition has turned photo-activated far-infrared thermal imaging into a promising tool for the characterization of biological tissues. By the sub-diffraction localization of sparse temperature increments primed by the sample absorption of modulated focused laser light, the distribution of (endogenous or exogenous) photo-thermal biomarkers can be reconstructed at tunable ∼10−50 μm resolution. We focus here on the theoretical modeling of laser-primed temperature variations and provide the guidelines to convert super-resolved temperature-based images into quantitative maps of the absolute molar concentration of photo-thermal probes. We start from camera-based temperature detection via Stefan–Boltzmann’s law, and elucidate the interplay of the camera point-spread-function and pixelated sensor size with the excitation beam waist in defining the amplitude of the measured temperature variations. This can be accomplished by the numerical solution of the three-dimensional heat equation in the presence of modulated laser illumination on the sample, which is characterized in terms of thermal diffusivity, conductivity, thickness, and concentration of photo-thermal species. We apply our data-analysis protocol to murine B16 melanoma biopsies, where melanin is mapped and quantified in label-free configuration at sub-diffraction 40 µm resolution. Our results, validated by an unsupervised machine-learning analysis of hematoxylin-and-eosin images of the same sections, suggest potential impact of super-resolved thermography in complementing standard histopathological analyses of melanocytic lesions.
{"title":"Quantitative active super-resolution thermal imaging: The melanoma case study","authors":"M. Marini, M. Bouzin, R. Scodellaro, L. D’alfonso, L. Sironi, F. Granucci, F. Mingozzi, G. Chirico, M. Collini","doi":"10.1515/bmc-2022-0015","DOIUrl":"https://doi.org/10.1515/bmc-2022-0015","url":null,"abstract":"Abstract Super-resolution image acquisition has turned photo-activated far-infrared thermal imaging into a promising tool for the characterization of biological tissues. By the sub-diffraction localization of sparse temperature increments primed by the sample absorption of modulated focused laser light, the distribution of (endogenous or exogenous) photo-thermal biomarkers can be reconstructed at tunable ∼10−50 μm resolution. We focus here on the theoretical modeling of laser-primed temperature variations and provide the guidelines to convert super-resolved temperature-based images into quantitative maps of the absolute molar concentration of photo-thermal probes. We start from camera-based temperature detection via Stefan–Boltzmann’s law, and elucidate the interplay of the camera point-spread-function and pixelated sensor size with the excitation beam waist in defining the amplitude of the measured temperature variations. This can be accomplished by the numerical solution of the three-dimensional heat equation in the presence of modulated laser illumination on the sample, which is characterized in terms of thermal diffusivity, conductivity, thickness, and concentration of photo-thermal species. We apply our data-analysis protocol to murine B16 melanoma biopsies, where melanin is mapped and quantified in label-free configuration at sub-diffraction 40 µm resolution. Our results, validated by an unsupervised machine-learning analysis of hematoxylin-and-eosin images of the same sections, suggest potential impact of super-resolved thermography in complementing standard histopathological analyses of melanocytic lesions.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"242 - 255"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43306866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Holubekova, Z. Kolková, I. Kasubova, Marek Samec, Alena Mazurakova, Lenka Koklesová, P. Kubatka, Tomas Rokos, E. Kozubík, K. Biringer, E. Kudela
Abstract One pillar of the predictive, preventive, and personalized medicine framework strategies is the female health. The evaluation of women’s lifestyle and dietary habits in context with genetic and modifiable risk factors may reflect the prevention of cervical cancer before the occurrence of clinical symptoms and prediction of cervical lesion behavior. The main aim of this review is to analyze publications in the field of precision medicine that allow the use of research knowledge of cervical microbiome, epigenetic modifications, and inflammation in potential application in clinical practice. Personalized approach in evaluating patient’s risk of future development of cervical abnormality should consider the biomarkers of the local microenvironment characterized by the microbial composition, epigenetic pattern of cervical epithelium, and presence of chronic inflammation. Novel sequencing techniques enable a more detailed characterization of actual state in cervical epithelium. Better understanding of all changes in multiomics level enables a better assessment of disease prognosis and selects the eligible targeted therapy in personalized medicine. Restoring of healthy vaginal microflora and reversing the outbreak of cervical abnormality can be also achieved by dietary habits as well as uptake of prebiotics, probiotics, synbiotics, microbial transplantation, and others.
{"title":"Interaction of cervical microbiome with epigenome of epithelial cells: Significance of inflammation to primary healthcare","authors":"V. Holubekova, Z. Kolková, I. Kasubova, Marek Samec, Alena Mazurakova, Lenka Koklesová, P. Kubatka, Tomas Rokos, E. Kozubík, K. Biringer, E. Kudela","doi":"10.1515/bmc-2022-0005","DOIUrl":"https://doi.org/10.1515/bmc-2022-0005","url":null,"abstract":"Abstract One pillar of the predictive, preventive, and personalized medicine framework strategies is the female health. The evaluation of women’s lifestyle and dietary habits in context with genetic and modifiable risk factors may reflect the prevention of cervical cancer before the occurrence of clinical symptoms and prediction of cervical lesion behavior. The main aim of this review is to analyze publications in the field of precision medicine that allow the use of research knowledge of cervical microbiome, epigenetic modifications, and inflammation in potential application in clinical practice. Personalized approach in evaluating patient’s risk of future development of cervical abnormality should consider the biomarkers of the local microenvironment characterized by the microbial composition, epigenetic pattern of cervical epithelium, and presence of chronic inflammation. Novel sequencing techniques enable a more detailed characterization of actual state in cervical epithelium. Better understanding of all changes in multiomics level enables a better assessment of disease prognosis and selects the eligible targeted therapy in personalized medicine. Restoring of healthy vaginal microflora and reversing the outbreak of cervical abnormality can be also achieved by dietary habits as well as uptake of prebiotics, probiotics, synbiotics, microbial transplantation, and others.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"61 - 80"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41386984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In the present work, we discuss the way in which the parallel application of the patch-clamp technique and the 2′,7′-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) fluorescence detection for recording luminal proton changes allows the functional characterization of nonelectrogenic potassium/proton vacuolar antiporters of the NHX (Na+/H+ exchanger) family. Moreover, we review the functional role of the tonoplast-specific phosphoinositide PI(3,5)P2, able to simultaneously inhibit the activity of NHXs and CLC-a transporters, whose coordinated action can play an important role in the water balance of plant cells.
{"title":"The phosphoinositide PI(3,5)P2 inhibits the activity of plant NHX proton/potassium antiporters: Advantages of a novel electrophysiological approach","authors":"A. Gradogna, J. M. Pardo, A. Carpaneto","doi":"10.1515/bmc-2022-0009","DOIUrl":"https://doi.org/10.1515/bmc-2022-0009","url":null,"abstract":"Abstract In the present work, we discuss the way in which the parallel application of the patch-clamp technique and the 2′,7′-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) fluorescence detection for recording luminal proton changes allows the functional characterization of nonelectrogenic potassium/proton vacuolar antiporters of the NHX (Na+/H+ exchanger) family. Moreover, we review the functional role of the tonoplast-specific phosphoinositide PI(3,5)P2, able to simultaneously inhibit the activity of NHXs and CLC-a transporters, whose coordinated action can play an important role in the water balance of plant cells.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"119 - 125"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46403111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Romano, G. Insero, Santiago Nonell Marrugat, F. Fusi
Abstract The use of light for therapeutic purposes dates back to ancient Egypt, where the sun itself was an innovative source, probably used for the first time to heal skin diseases. Since then, technical innovation and advancement in medical sciences have produced newer and more sophisticated solutions for light-emitting sources and their applications in medicine. Starting from a brief historical introduction, the concept of innovation in light sources is discussed and analysed, first from a technical point of view and then in the light of their fitness to improve existing therapeutic protocols or propose new ones. If it is true that a “pure” technical advancement is a good reason for innovation, only a sub-system of those advancements is innovative for phototherapy. To illustrate this concept, the most representative examples of innovative light sources are presented and discussed, both from a technical point of view and from the perspective of their diffusion and applications in the clinical field.
{"title":"Innovative light sources for phototherapy","authors":"G. Romano, G. Insero, Santiago Nonell Marrugat, F. Fusi","doi":"10.1515/bmc-2022-0020","DOIUrl":"https://doi.org/10.1515/bmc-2022-0020","url":null,"abstract":"Abstract The use of light for therapeutic purposes dates back to ancient Egypt, where the sun itself was an innovative source, probably used for the first time to heal skin diseases. Since then, technical innovation and advancement in medical sciences have produced newer and more sophisticated solutions for light-emitting sources and their applications in medicine. Starting from a brief historical introduction, the concept of innovation in light sources is discussed and analysed, first from a technical point of view and then in the light of their fitness to improve existing therapeutic protocols or propose new ones. If it is true that a “pure” technical advancement is a good reason for innovation, only a sub-system of those advancements is innovative for phototherapy. To illustrate this concept, the most representative examples of innovative light sources are presented and discussed, both from a technical point of view and from the perspective of their diffusion and applications in the clinical field.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"256 - 271"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43759301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Hydration of water affects the dynamics and in turn the activity of biomacromolecules. We investigated the dependence of the librational oscillations and the dynamical transition on the hydrating conditions of two globular proteins with different structure and size, namely β-lactoglobulin (βLG) and human serum albumin (HSA), by spin-label electron paramagnetic resonance (EPR) in the temperature range of 120–270 K. The proteins were spin-labeled with 5-maleimide spin-label on free cysteins and prepared in the lyophilized state, at low (h = 0.12) and full (h = 2) hydration levels in buffer. The angular amplitudes of librations are small and almost temperature independent for both lyophilized proteins. Therefore, in these samples, the librational dynamics is restricted and the dynamical transition is absent. In the small and compact beta-structured βLG, the angular librational amplitudes increase with temperature and hydrating conditions, whereas hydration-independent librational oscillations whose amplitudes rise with temperature are recorded in the large and flexible alpha-structured HSA. Both βLG and HSA at low and fully hydration levels undergo the dynamical transition at about 230 K. The overall results indicate that protein librational dynamics is activated at the low hydration level h = 0.12 and highlight biophysical properties that are common to other biosamples at cryogenic temperatures.
{"title":"Low-temperature librations and dynamical transition in proteins at differing hydration levels","authors":"Erika Aloi, R. Bartucci, R. Guzzi","doi":"10.1515/bmc-2022-0007","DOIUrl":"https://doi.org/10.1515/bmc-2022-0007","url":null,"abstract":"Abstract Hydration of water affects the dynamics and in turn the activity of biomacromolecules. We investigated the dependence of the librational oscillations and the dynamical transition on the hydrating conditions of two globular proteins with different structure and size, namely β-lactoglobulin (βLG) and human serum albumin (HSA), by spin-label electron paramagnetic resonance (EPR) in the temperature range of 120–270 K. The proteins were spin-labeled with 5-maleimide spin-label on free cysteins and prepared in the lyophilized state, at low (h = 0.12) and full (h = 2) hydration levels in buffer. The angular amplitudes of librations are small and almost temperature independent for both lyophilized proteins. Therefore, in these samples, the librational dynamics is restricted and the dynamical transition is absent. In the small and compact beta-structured βLG, the angular librational amplitudes increase with temperature and hydrating conditions, whereas hydration-independent librational oscillations whose amplitudes rise with temperature are recorded in the large and flexible alpha-structured HSA. Both βLG and HSA at low and fully hydration levels undergo the dynamical transition at about 230 K. The overall results indicate that protein librational dynamics is activated at the low hydration level h = 0.12 and highlight biophysical properties that are common to other biosamples at cryogenic temperatures.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"81 - 88"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41642093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Following structural determination by recent advances in electron cryomicroscopy, it is now well established that the respiratory Complexes I–IV in oxidative phosphorylation (OXPHOS) are organized into supercomplexes in the respirasome. Nonetheless, the reason for the existence of the OXPHOS supercomplexes and their functional role remains an enigma. Several hypotheses have been proposed for the existence of these supercomplex supercomplexes. A commonly-held view asserts that they enhance catalysis by substrate channeling. However, this – and other views – has been challenged based on structural and biophysical information. Hence, new ideas, concepts, and frameworks are needed. Here, a new model of energy transfer in OXPHOS is developed on the basis of biochemical data on the pure competitive inhibition of anionic substrates like succinate by the classical anionic uncouplers of OXPHOS (2,4-dinitrophenol, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone, and dicoumarol), and pharmacological data on the unique site-selective, energy-linked inhibition of energy conservation pathways in mitochondria induced by the guanidine derivatives. It is further found that uncouplers themselves are site-specific and exhibit differential selectivity and efficacy in reversing the inhibition caused by the Site 1/Complex I or Site 2/Complexes II–III-selective guanidine derivatives. These results lead to new vistas and sufficient complexity in the network of energy conservation pathways in the mitochondrial respiratory chain that necessitate discrete points of interaction with two classes of guanidine derivatives and uncoupling agents and thereby separate and distinct energy transfer pathways between Site 1 and Site 2 and the intermediate that energizes adenosine triphosphate (ATP) synthesis by Complex V. Interpretation based on Mitchell’s single-ion chemiosmotic theory that postulates only a single energy pool is inadequate to rationalize the data and account for the required complexity. The above results and available information are shown to be explained by Nath’s two-ion theory of energy coupling and ATP synthesis, involving coupled movement of succinate anions and protons, along with the requirement postulated by the theory for maintenance of homeostasis and ion translocation across the energy-transducing membrane of both succinate monoanions and succinate dianions by Complexes I–V in the OXPHOS supercomplexes. The new model of energy transfer in mitochondria is mapped onto the solved structures of the supercomplexes and integrated into a consistent model with the three-dimensional electron microscope computer tomography visualization of the internal structure of the cristae membranes in mammalian mitochondria. The model also offers valuable insights into diseased states induced in type 2 diabetes and especially in Alzheimer’s and other neurodegenerative diseases that involve mitochondrial dysfunction.
摘要:在电子低温显微镜的最新进展下，现在已经确定氧化磷酸化(OXPHOS)中的呼吸复合物I-IV在呼吸小体中被组织成超复合物。尽管如此，OXPHOS超复合体存在的原因及其功能作用仍然是一个谜。对于这些超复合体的存在，已经提出了几个假设。一种普遍持有的观点认为，它们通过底物通道增强催化作用。然而，基于结构和生物物理信息，这一观点和其他观点受到了挑战。因此，需要新的想法、概念和框架。本研究基于OXPHOS经典阴离子解耦剂(2,4-二硝基苯酚、羰基氰化物4-(三氟甲氧基)苯腙和二oumarol)对琥珀酸盐等阴离子底物的纯竞争性抑制的生化数据，以及胍衍生物诱导的线粒体能量守恒途径的独特位点选择性、能量连锁抑制的药理学数据，建立了OXPHOS中新的能量传递模型。进一步发现解偶联剂本身具有位点特异性，在逆转由Site 1/Complex I或Site 2/Complexes ii - iii选择性胍衍生物引起的抑制方面表现出不同的选择性和有效性。这些结果为线粒体呼吸链中的能量守恒途径网络带来了新的前景和足够的复杂性，这需要与两类胍衍生物和解偶联剂相互作用的离散点，从而在Site 1和Site 2以及激活三磷酸腺苷(ATP)合成的中间体之间分离和不同的能量转移途径假设只有一个能量池不足以使数据合理化并解释所需的复杂性。上述结果和现有信息可以用Nath的能量耦合和ATP合成双离子理论来解释，该理论涉及琥珀酸阴离子和质子的耦合运动，以及OXPHOS超配合物中配合物I-V在琥珀酸单阴离子和琥珀酸双阴离子的能量传导膜上维持稳态和离子转运的理论假设。线粒体能量传递的新模型被映射到超复合体的已解结构上，并与哺乳动物线粒体嵴膜内部结构的三维电子显微镜计算机断层扫描可视化集成到一个一致的模型中。该模型还为2型糖尿病，特别是阿尔茨海默氏症和其他涉及线粒体功能障碍的神经退行性疾病诱导的疾病状态提供了有价值的见解。
{"title":"Supercomplex supercomplexes: Raison d’etre and functional significance of supramolecular organization in oxidative phosphorylation","authors":"S. Nath","doi":"10.1515/bmc-2022-0021","DOIUrl":"https://doi.org/10.1515/bmc-2022-0021","url":null,"abstract":"Abstract Following structural determination by recent advances in electron cryomicroscopy, it is now well established that the respiratory Complexes I–IV in oxidative phosphorylation (OXPHOS) are organized into supercomplexes in the respirasome. Nonetheless, the reason for the existence of the OXPHOS supercomplexes and their functional role remains an enigma. Several hypotheses have been proposed for the existence of these supercomplex supercomplexes. A commonly-held view asserts that they enhance catalysis by substrate channeling. However, this – and other views – has been challenged based on structural and biophysical information. Hence, new ideas, concepts, and frameworks are needed. Here, a new model of energy transfer in OXPHOS is developed on the basis of biochemical data on the pure competitive inhibition of anionic substrates like succinate by the classical anionic uncouplers of OXPHOS (2,4-dinitrophenol, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone, and dicoumarol), and pharmacological data on the unique site-selective, energy-linked inhibition of energy conservation pathways in mitochondria induced by the guanidine derivatives. It is further found that uncouplers themselves are site-specific and exhibit differential selectivity and efficacy in reversing the inhibition caused by the Site 1/Complex I or Site 2/Complexes II–III-selective guanidine derivatives. These results lead to new vistas and sufficient complexity in the network of energy conservation pathways in the mitochondrial respiratory chain that necessitate discrete points of interaction with two classes of guanidine derivatives and uncoupling agents and thereby separate and distinct energy transfer pathways between Site 1 and Site 2 and the intermediate that energizes adenosine triphosphate (ATP) synthesis by Complex V. Interpretation based on Mitchell’s single-ion chemiosmotic theory that postulates only a single energy pool is inadequate to rationalize the data and account for the required complexity. The above results and available information are shown to be explained by Nath’s two-ion theory of energy coupling and ATP synthesis, involving coupled movement of succinate anions and protons, along with the requirement postulated by the theory for maintenance of homeostasis and ion translocation across the energy-transducing membrane of both succinate monoanions and succinate dianions by Complexes I–V in the OXPHOS supercomplexes. The new model of energy transfer in mitochondria is mapped onto the solved structures of the supercomplexes and integrated into a consistent model with the three-dimensional electron microscope computer tomography visualization of the internal structure of the cristae membranes in mammalian mitochondria. The model also offers valuable insights into diseased states induced in type 2 diabetes and especially in Alzheimer’s and other neurodegenerative diseases that involve mitochondrial dysfunction.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"272 - 288"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41928029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Bruno, Marilena Margiotta, Marco Cozzolino, P. Bianchini, A. Diaspro, L. Cavanna, M. Tognolini, S. Abbruzzetti, C. Viappiani
Abstract The photodynamic treatment for antimicrobial applications or anticancer therapy relies on reactive oxygen species generated by photosensitizing molecules after absorption of visible or near-infrared light. If the photosensitizing molecule is in close vicinity of the microorganism or the malignant cell, a photocytotoxic action is exerted. Therefore, the effectiveness of photosensitizing compounds strongly depends on their capability to target microbial or cancer-specific proteins. In this study, we report on the preparation and preliminary characterization of human recombinant myoglobin fused to the vasoactive intestinal peptide to target vasoactive intestinal peptide receptor (VPAC) receptors. Fe-protoporphyrin IX was replaced by the photosensitizing compound Zn-protoporphyrin IX. Taking advantage of the fluorescence emission by Zn-protoporphyrin IX, we show that the construct can bind prostate cancer cells where the VPAC receptors are expressed.
{"title":"A photosensitizing fusion protein with targeting capabilities","authors":"S. Bruno, Marilena Margiotta, Marco Cozzolino, P. Bianchini, A. Diaspro, L. Cavanna, M. Tognolini, S. Abbruzzetti, C. Viappiani","doi":"10.1515/bmc-2022-0014","DOIUrl":"https://doi.org/10.1515/bmc-2022-0014","url":null,"abstract":"Abstract The photodynamic treatment for antimicrobial applications or anticancer therapy relies on reactive oxygen species generated by photosensitizing molecules after absorption of visible or near-infrared light. If the photosensitizing molecule is in close vicinity of the microorganism or the malignant cell, a photocytotoxic action is exerted. Therefore, the effectiveness of photosensitizing compounds strongly depends on their capability to target microbial or cancer-specific proteins. In this study, we report on the preparation and preliminary characterization of human recombinant myoglobin fused to the vasoactive intestinal peptide to target vasoactive intestinal peptide receptor (VPAC) receptors. Fe-protoporphyrin IX was replaced by the photosensitizing compound Zn-protoporphyrin IX. Taking advantage of the fluorescence emission by Zn-protoporphyrin IX, we show that the construct can bind prostate cancer cells where the VPAC receptors are expressed.","PeriodicalId":38392,"journal":{"name":"Biomolecular Concepts","volume":"13 1","pages":"175 - 182"},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49139331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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