Yusuke Kobayashi, T. Amano, K. Taga, Yasushi Yamamoto, Z. Shervani, Masato Yamamoto
We have synthesized first novel dihexadecyl phosphate (DHGP-n) gemini surfactants containing alkyl chain ((CnH2n); n = 3, 4, 5, and 6) spacers. Surfactants were used to form monolayers on water surface. Surface tension measurement (STm), Brewster angle microscopy (BAM), and density functional theory (DFT) calculation were used to investigate these monolayers. Surface pressure (π) and molecular area (A); π-A isotherm curves of all DHGP-n gemini surfactants showed a gradual increase in surface pressure without any break points in the curves, confirmed the formation of liquid-expand (LE) type monolayers. BAM observations also supported the STm results. Limited molecular area (A0) of these monolayers depended on the spacer of gemini surfactants without spacer n = 4. Longer alkyl chain spacer in the series had higher value of A0 in π-A isotherm plots. In the series, A0 of spacer n = 4 was smallest among A0 values of other spacers. Density functional theory (DFT) method calculation also confirmed π-A isotherm curves pattern of these surfactants. Calculation showed that both odd and even numbers and length of the alkyl chain spacer influenced the structure of DHGP-n monolayer formation on the water surface.
{"title":"Surface Properties of Novel Surfactant, Dihexadecyl Gemini Phosphate, Monolayers on Water Surface by Dropping Method","authors":"Yusuke Kobayashi, T. Amano, K. Taga, Yasushi Yamamoto, Z. Shervani, Masato Yamamoto","doi":"10.4236/JBPC.2017.84004","DOIUrl":"https://doi.org/10.4236/JBPC.2017.84004","url":null,"abstract":"We have synthesized first novel dihexadecyl phosphate (DHGP-n) gemini surfactants containing alkyl chain ((CnH2n); n = 3, 4, 5, and 6) spacers. Surfactants were used to form monolayers on water surface. Surface tension measurement (STm), Brewster angle microscopy (BAM), and density functional theory (DFT) calculation were used to investigate these monolayers. Surface pressure (π) and molecular area (A); π-A isotherm curves of all DHGP-n gemini surfactants showed a gradual increase in surface pressure without any break points in the curves, confirmed the formation of liquid-expand (LE) type monolayers. BAM observations also supported the STm results. Limited molecular area (A0) of these monolayers depended on the spacer of gemini surfactants without spacer n = 4. Longer alkyl chain spacer in the series had higher value of A0 in π-A isotherm plots. In the series, A0 of spacer n = 4 was smallest among A0 values of other spacers. Density functional theory (DFT) method calculation also confirmed π-A isotherm curves pattern of these surfactants. Calculation showed that both odd and even numbers and length of the alkyl chain spacer influenced the structure of DHGP-n monolayer formation on the water surface.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47937464","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}
F. Marques, Alysson Luiz Mendes da Silva, R. Mattoso, Roque Aras Júnior, Rogério Jorge B. de Oliveira, Júlio Cezar de Abreu Santos, F. D. Couto, R. Couto
End stage-renal-disease (ESRD) is associated with dyslipidemia and premature atherosclerosis. The study evaluates the effect of hemodialysis (HD) on HDL-remodeling between pre- and post-HD. Was conducted a cross-sectional study with 50 ESRD male patients, undergoing HD at Ana Neri Hospital, Salvador, Brazil. All individuals were on HD for at least 3 months, into a three sessions protocol for 3 - 4 hours per week, with a polysulfone low-flow basic-dialyzing-membrane and unfractionated-heparin. HDL Phospholipid-incorporation was measured by 14C-PL-scintillation-counting, expressed as %14C-PL/mL/hour. Paraoxonase (PON-1) activity was measured by spectrophotometry using paraoxon as substrate. Cardiovascular risk ratios and atherogenic index of plasma were calculated. Total cholesterol, HDL-C and non-HDL-C increased at post-HD on all age groups, but without triglycerides (TG) changes. TG/HDL-C decreased in 30 - 39 and 40 - 49 year (y) at post-HD (p 60 y, after HD (p 60 (p 60 y, at post-HD (p 60 y, both at pre- (r = 0.63; p = 0.029) and post-HD (r = 0.65; p = 0.022). PON-1 activity increased at pre- (59 ± 30) and post-HD (73 ± 38) in 50 - 59 y (p 60 y (p < 0.05), when compared to pre- and post-HD. ESRD patients undergoing HD shows important changes on lipid-profile, PON-1-activity, cardiac risk ratios and HDL-remodeling. These results demonstrate the influence of HD with a polysulfone low-flow basic-dialyzing-membrane and unfractionated-heparin on lipoprotein metabolism.
{"title":"Low-Flow Polysulfone Hemodialysis Alters Lipoprotein Parameters, Paraoxonase Activity and in Vitro Incorporation of Phospholipids","authors":"F. Marques, Alysson Luiz Mendes da Silva, R. Mattoso, Roque Aras Júnior, Rogério Jorge B. de Oliveira, Júlio Cezar de Abreu Santos, F. D. Couto, R. Couto","doi":"10.4236/JBPC.2017.83003","DOIUrl":"https://doi.org/10.4236/JBPC.2017.83003","url":null,"abstract":"End stage-renal-disease (ESRD) is associated with dyslipidemia and premature atherosclerosis. The study evaluates the effect of hemodialysis (HD) on HDL-remodeling between pre- and post-HD. Was conducted a cross-sectional study with 50 ESRD male patients, undergoing HD at Ana Neri Hospital, Salvador, Brazil. All individuals were on HD for at least 3 months, into a three sessions protocol for 3 - 4 hours per week, with a polysulfone low-flow basic-dialyzing-membrane and unfractionated-heparin. HDL Phospholipid-incorporation was measured by 14C-PL-scintillation-counting, expressed as %14C-PL/mL/hour. Paraoxonase (PON-1) activity was measured by spectrophotometry using paraoxon as substrate. Cardiovascular risk ratios and atherogenic index of plasma were calculated. Total cholesterol, HDL-C and non-HDL-C increased at post-HD on all age groups, but without triglycerides (TG) changes. TG/HDL-C decreased in 30 - 39 and 40 - 49 year (y) at post-HD (p 60 y, after HD (p 60 (p 60 y, at post-HD (p 60 y, both at pre- (r = 0.63; p = 0.029) and post-HD (r = 0.65; p = 0.022). PON-1 activity increased at pre- (59 ± 30) and post-HD (73 ± 38) in 50 - 59 y (p 60 y (p < 0.05), when compared to pre- and post-HD. ESRD patients undergoing HD shows important changes on lipid-profile, PON-1-activity, cardiac risk ratios and HDL-remodeling. These results demonstrate the influence of HD with a polysulfone low-flow basic-dialyzing-membrane and unfractionated-heparin on lipoprotein metabolism.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43683532","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}
The new metal complexes of Cu(II), Ni(II) and Co(II) with the new ligand derived from isatine and 1,2-diaminocyclohexane were synthesized and biologically screened. The synthesized complexes and ligand were characterized by spectroscopic FT-IR, UV-VIS, 1H-NMR and elemental analyses. The ligand and complexes were screened for their antibacterial activities against three different strains, namely E. coli, P. aeruginosa and S. aureus. In particular, the Co(II) and Cu-complexes exhibited excellent antibacterial activities compared to the reference compound.
{"title":"Synthesis and Antibacterial Studies of Metal Complexes of Cu(II), Ni(II) and Co(II) with Tetradentate Ligand","authors":"Alyaa Abdulhasan Abdulkarem","doi":"10.4236/JBPC.2017.82002","DOIUrl":"https://doi.org/10.4236/JBPC.2017.82002","url":null,"abstract":"The new metal complexes of Cu(II), Ni(II) and Co(II) with the new ligand derived from isatine and 1,2-diaminocyclohexane were synthesized and biologically screened. The synthesized complexes and ligand were characterized by spectroscopic FT-IR, UV-VIS, 1H-NMR and elemental analyses. The ligand and complexes were screened for their antibacterial activities against three different strains, namely E. coli, P. aeruginosa and S. aureus. In particular, the Co(II) and Cu-complexes exhibited excellent antibacterial activities compared to the reference compound.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47647144","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}
I. Adejoro, Sodiq O. Waheed, O. Adeboye, F. U. Akhigbe
Ulcer is one of the life threatening diseases. It is an open sore on an external or internal surface of the body caused by a break in the skin or mucous membrane which fails to heal. In this work, specific ligands that are suitable for ulcer have been studied computationally. Docking of the triterpenoids of Lonchocarpus cyanescens with target proteins of PDB codes 1AFC, 1AXM and 2AXM were performed using AutoDock Vina and Pymol for docking and post-docking analysis, respectively. In this study, the triterpenoid ligands with binding affinity/inhibitory constants -7.2/5.21, -6.5/16.99 and -6.2/28.20 for OH, and -6.7/12.12, -6.3/23.82 and -6.1/33.40 for OCH3 were compared with the standard ligands. Our study indicates that the results corresponding to triterpenoid ligands are close to standard ligands.
{"title":"Molecular Docking of the Inhibitory Activities of Triterpenoids of Lonchocarpus cyanescens against Ulcer","authors":"I. Adejoro, Sodiq O. Waheed, O. Adeboye, F. U. Akhigbe","doi":"10.4236/JBPC.2017.81001","DOIUrl":"https://doi.org/10.4236/JBPC.2017.81001","url":null,"abstract":"Ulcer is one of the life threatening diseases. It is an open sore on an external or internal surface of the body caused by a break in the skin or mucous membrane which fails to heal. In this work, specific ligands that are suitable for ulcer have been studied computationally. Docking of the triterpenoids of Lonchocarpus cyanescens with target proteins of PDB codes 1AFC, 1AXM and 2AXM were performed using AutoDock Vina and Pymol for docking and post-docking analysis, respectively. In this study, the triterpenoid ligands with binding affinity/inhibitory constants -7.2/5.21, -6.5/16.99 and -6.2/28.20 for OH, and -6.7/12.12, -6.3/23.82 and -6.1/33.40 for OCH3 were compared with the standard ligands. Our study indicates that the results corresponding to triterpenoid ligands are close to standard ligands.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46821504","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}
We previously showed that increased mitochondrial inner membrane permeability which is known as mitochondrial permeability transition (MPT) is triggered by adding succinate in the presence of the diabetogenic agent alloxan. Here, our aim was to investigate whether mitochondrial respiration is associated with alloxan-induced MPT. After mitochondria isolated from rat liver were incubated with alloxan at 37°C for 5 min, the addition of succinate immediately triggered the MPT in the presence of rotenone. However, little or no induction occurred at incubation temperatures below 25°C. Malate/glutamate also triggered MPT by alloxan in the absence of rotenone. In mitochondrial suspensions containing alloxan, succinate accelerated oxygen consumption that was completely inhibited by cyanide. These results suggest that mitochondrial respiration is associated with the alloxan-induced MPT. Alloxan radical production was investigated using ESR spectroscopy. Mitochondria incubated with succinate and alloxan elicited low signal intensity (radical formation) that increased significantly in the presence of cyanide. When the incubation of alloxan with mitochondria after the addition of succinate, a little intensity of the signal was observed, but it was remarkably increased after the addition of cyanide. Ubiquinone analogues inhibited the MPT induction. These results suggest that the initiation of MPT is associated with alloxan redox cycling via an electron transfer process at a quinone-binding site in respiratory mitochondria.
{"title":"Mitochondrial Respiration Is Associated with Alloxan-Induced Mitochondrial Permeability Transition","authors":"K. Sakurai, M. Itoh","doi":"10.4236/JBPC.2016.74008","DOIUrl":"https://doi.org/10.4236/JBPC.2016.74008","url":null,"abstract":"We previously showed that increased mitochondrial inner membrane permeability which is known as mitochondrial permeability transition (MPT) is triggered by adding succinate in the presence of the diabetogenic agent alloxan. Here, our aim was to investigate whether mitochondrial respiration is associated with alloxan-induced MPT. After mitochondria isolated from rat liver were incubated with alloxan at 37°C for 5 min, the addition of succinate immediately triggered the MPT in the presence of rotenone. However, little or no induction occurred at incubation temperatures below 25°C. Malate/glutamate also triggered MPT by alloxan in the absence of rotenone. In mitochondrial suspensions containing alloxan, succinate accelerated oxygen consumption that was completely inhibited by cyanide. These results suggest that mitochondrial respiration is associated with the alloxan-induced MPT. Alloxan radical production was investigated using ESR spectroscopy. Mitochondria incubated with succinate and alloxan elicited low signal intensity (radical formation) that increased significantly in the presence of cyanide. When the incubation of alloxan with mitochondria after the addition of succinate, a little intensity of the signal was observed, but it was remarkably increased after the addition of cyanide. Ubiquinone analogues inhibited the MPT induction. These results suggest that the initiation of MPT is associated with alloxan redox cycling via an electron transfer process at a quinone-binding site in respiratory mitochondria.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70904752","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}
T. Yokoyama, D. Yoshida, H. Mori, Masaya Okabe, Z. Shervani, K. Taga, Yasushi Yamamoto, Ayumi Sumino, Takehisa Dewa, M. Nango, Masato Yamamoto
Morphology of dipalmitoyl phosphatidyl choline (DPPC)-cholesterol (Chol) mixed monolayer formed on water surface by dropping method was investigated using surface tension measurement (STm), Brewster angle microscopy (BAM), and fluorescence microscopy (FM). STm showed strong condensation effect of Chol in fluidic DPPC monolayer. Excess area (Sex) from mean mixing state of DPPC and Chol was about twice larger than that by general compression method in the range from xC = 0.2 to 0.4 (xC: mole fraction of Chol). BAM and FM images showed clearly that the fluidic DPPC monolayer changed to condensed rigid monolayer due to the condensation effect of Chol. At more than xC = 0.3 DPPC-Chol mixed monolayer changed to condensed state similar to the Chol monolayer. These results support previous reports by compression method that Chol molecule demonstrates the strong condensation effect to the fluidic monolayer and also indicate that dropping method enables to form unique monolayer on the water surface.
{"title":"MorphologicaObservation of Specific Condensation Effect of Cholesterol on Dipalmitoyl Phosphatidyl Choline (DPPC) Monolayer by Dropping Method","authors":"T. Yokoyama, D. Yoshida, H. Mori, Masaya Okabe, Z. Shervani, K. Taga, Yasushi Yamamoto, Ayumi Sumino, Takehisa Dewa, M. Nango, Masato Yamamoto","doi":"10.4236/JBPC.2016.74009","DOIUrl":"https://doi.org/10.4236/JBPC.2016.74009","url":null,"abstract":"Morphology of dipalmitoyl phosphatidyl choline (DPPC)-cholesterol (Chol) mixed monolayer formed on water surface by dropping method was investigated using surface tension measurement (STm), Brewster angle microscopy (BAM), and fluorescence microscopy (FM). STm showed strong condensation effect of Chol in fluidic DPPC monolayer. Excess area (Sex) from mean mixing state of DPPC and Chol was about twice larger than that by general compression method in the range from xC = 0.2 to 0.4 (xC: mole fraction of Chol). BAM and FM images showed clearly that the fluidic DPPC monolayer changed to condensed rigid monolayer due to the condensation effect of Chol. At more than xC = 0.3 DPPC-Chol mixed monolayer changed to condensed state similar to the Chol monolayer. These results support previous reports by compression method that Chol molecule demonstrates the strong condensation effect to the fluidic monolayer and also indicate that dropping method enables to form unique monolayer on the water surface.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70904800","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}
Multidrug resistance protein 5 (MRP5/ABCC5) is a 161 kDa member of the super family of ATP- binding cassette (ABC) superfamily of transmembrane transporters that is clinically relevant for its ability to confer multidrug resistance by actively e?uxing anticancer drugs. ABCC5 has also been identified as an efflux transporter of cGMP (cyclic guanosine monophosphate). Elevated intracellular levels of cGMP in cancer cells have been implicated in several clinical studies, that may induce apoptosis, and as a result many different cancer cells seem to overcome this deleterious effect by increased efflux of cGMP through ABCC5. Thus inhibition of ABCC5 may have cytotoxic effects mediated through cGMP and it will also increase the intracellular concentration of other drugs that are aimed for the treatment of cancer which are otherwise exported out of the cells. Considering the functional importance and lack of X-ray crystal structure of ABCC5, present work was undertaken to construct 3D structure of protein using homology modeling protocol of YASARA structure (V. 16.3.28). In this study, five different ABC templates (PDB ID’s: 4F4C, 4Q9H, 4M1M, 4M2T and 4KSD) were used for homology modeling. Five models were constructed on each template and a hybrid model was built using all five templates. All models were refined and ranked as per their overall Z-score. The top ranked ABBC5 model was based on template 4Q9H that had 91.2% of residues in allowed regions as revealed by PROCHECK-NMR and the QMEAN score was 0.54 which indicated a reliable model. The results of the study and the proposed model can be further used for elucidating the structural and functional aspects of ABCC5 and to gain more insights to the molecular basis of ABCC5 inhibition through docking studies.
{"title":"Molecular Modelling of Human Multidrug Resistance Protein 5 (ABCC5)","authors":"Natesh Singh","doi":"10.4236/JBPC.2016.73006","DOIUrl":"https://doi.org/10.4236/JBPC.2016.73006","url":null,"abstract":"Multidrug resistance protein 5 (MRP5/ABCC5) is a 161 kDa member of the super family of ATP- binding cassette (ABC) superfamily of transmembrane transporters that is clinically relevant for its ability to confer multidrug resistance by actively e?uxing anticancer drugs. ABCC5 has also been identified as an efflux transporter of cGMP (cyclic guanosine monophosphate). Elevated intracellular levels of cGMP in cancer cells have been implicated in several clinical studies, that may induce apoptosis, and as a result many different cancer cells seem to overcome this deleterious effect by increased efflux of cGMP through ABCC5. Thus inhibition of ABCC5 may have cytotoxic effects mediated through cGMP and it will also increase the intracellular concentration of other drugs that are aimed for the treatment of cancer which are otherwise exported out of the cells. Considering the functional importance and lack of X-ray crystal structure of ABCC5, present work was undertaken to construct 3D structure of protein using homology modeling protocol of YASARA structure (V. 16.3.28). In this study, five different ABC templates (PDB ID’s: 4F4C, 4Q9H, 4M1M, 4M2T and 4KSD) were used for homology modeling. Five models were constructed on each template and a hybrid model was built using all five templates. All models were refined and ranked as per their overall Z-score. The top ranked ABBC5 model was based on template 4Q9H that had 91.2% of residues in allowed regions as revealed by PROCHECK-NMR and the QMEAN score was 0.54 which indicated a reliable model. The results of the study and the proposed model can be further used for elucidating the structural and functional aspects of ABCC5 and to gain more insights to the molecular basis of ABCC5 inhibition through docking studies.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70904736","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}
Thi Thuy Minh Nguyen, V. Chintamsetti, S. Chennuru
Lipid rafts are sterol and sphingolipid rich membrane domains that possibly may play roles in multiple cellular processes. These domains are still the matter of debate and it is still unknown by which mechanism if any and organisms promote their formation. This study centers on the ease of in vitro formation of lipid rafts-like structures as it relates to the relative availability of sphingolipids, phospholipids, cholesterol, and membrane proteins. Following a 12 h incubation period, isolation and extraction of the lipid rafts-like assemblies, the composition of the structures was evaluated using HPLC. Cholesterol and sphingomyelin were detected at 206 nm and phosphatidylcholine was detected at 254 nm. Identification of lactose permease, a typical membrane protein, was done using FTIR. The thermal stability of the produced structures was also determined. Results show that the addition of cholesterol significantly increased both the amount of insoluble lipid rafts-like structures and their stability, and that the availability of a minimum amount of sphingolipid was necessary to produce larger amounts of more stable structures. However, the addition of phospholipids hindered the formation of lipid rafts-like assemblies and those formed were generally less stable.
{"title":"The Stability of Lipid Rafts-Like Micro-Domains Is Dependent on the Available Amount of Cholesterol","authors":"Thi Thuy Minh Nguyen, V. Chintamsetti, S. Chennuru","doi":"10.4236/JBPC.2016.73007","DOIUrl":"https://doi.org/10.4236/JBPC.2016.73007","url":null,"abstract":"Lipid rafts are sterol and sphingolipid rich membrane domains that possibly may play roles in multiple cellular processes. These domains are still the matter of debate and it is still unknown by which mechanism if any and organisms promote their formation. This study centers on the ease of in vitro formation of lipid rafts-like structures as it relates to the relative availability of sphingolipids, phospholipids, cholesterol, and membrane proteins. Following a 12 h incubation period, isolation and extraction of the lipid rafts-like assemblies, the composition of the structures was evaluated using HPLC. Cholesterol and sphingomyelin were detected at 206 nm and phosphatidylcholine was detected at 254 nm. Identification of lactose permease, a typical membrane protein, was done using FTIR. The thermal stability of the produced structures was also determined. Results show that the addition of cholesterol significantly increased both the amount of insoluble lipid rafts-like structures and their stability, and that the availability of a minimum amount of sphingolipid was necessary to produce larger amounts of more stable structures. However, the addition of phospholipids hindered the formation of lipid rafts-like assemblies and those formed were generally less stable.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70904743","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}
Yusuke Kobayashi, R. Hirai, D. Ito, Yasushi Yamamoto, K. Taga, Z. Shervani
We have investigated the morphology of novel 3, 4-bis-alkyloxycarbonyl-hexanedioic acid monolayer (alkyl chain number n = 12, 14, and 16) formed on the water surface by dropping method using Surface Tension measurement (STm) and Brewster Angle Microscopy (BAM). Surfactant of 3, 4-bis-alkyloxycarbonyl-hexanedioic acid has a gemini type structure. π-A isotherm curves (STm) of two gemini surfactants of n = 12 and 14 showed gradual increase in surface pressure, while that of n = 16 showed gradual increase, a stagnant range and finally steep increase. BAM observation showed each image corresponding to the result of STm measurement. From STm and BAM results of surfactants, it is found that surfactant of n = 12 and 14 form Liquid-Expand (LE) type monolayer, while that of n = 16 formed Liquid-Condensed (LC) type monolayer including LE-LC phase transition.
{"title":"Morphology Observation of Novel 3, 4-Bis-Alkyloxycarbonyl-Hexanedioic Acid Monolayer on Water Surface by Dropping Method","authors":"Yusuke Kobayashi, R. Hirai, D. Ito, Yasushi Yamamoto, K. Taga, Z. Shervani","doi":"10.4236/JBPC.2016.72004","DOIUrl":"https://doi.org/10.4236/JBPC.2016.72004","url":null,"abstract":"We have investigated the morphology of novel 3, 4-bis-alkyloxycarbonyl-hexanedioic acid monolayer (alkyl chain number n = 12, 14, and 16) formed on the water surface by dropping method using Surface Tension measurement (STm) and Brewster Angle Microscopy (BAM). Surfactant of 3, 4-bis-alkyloxycarbonyl-hexanedioic acid has a gemini type structure. π-A isotherm curves (STm) of two gemini surfactants of n = 12 and 14 showed gradual increase in surface pressure, while that of n = 16 showed gradual increase, a stagnant range and finally steep increase. BAM observation showed each image corresponding to the result of STm measurement. From STm and BAM results of surfactants, it is found that surfactant of n = 12 and 14 form Liquid-Expand (LE) type monolayer, while that of n = 16 formed Liquid-Condensed (LC) type monolayer including LE-LC phase transition.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70904831","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}
H. Hoang, Fidelis Manyanga, M. K. Morakinyo, V. Pinkert, Ferdous Sarwary, Daniel J. Fish, G. Brewood, A. S. Benight
Thermal denaturation and stability of two commercially available preparations of Human Serum Albumin (HSA), differing in their advertised level of purity, were investigated by differential scanning calorimetry (DSC). These protein samples were 99% pure HSA (termed HSA99) and 96% pure HSA (termed HSA96). According to the supplier, the 3% difference in purity between HSA96 and HSA99 is primarily attributed to the presence of globulins and fatty acids. Our primary aim was to investigate the utility of DSC in discerning changes in HSA that occur when the protein is specifically adducted, and determine how adduct formation manifests itself in HSA denaturation curves, or thermograms, measured by DSC. Effects of site specific covalent attachment of biotin (the adduct) on the thermodynamic stability of HSA were investigated. Each of the HSA preparations was modified by biotinylation targeting a single site, or multiple sites on the protein structure. Thermograms of both modified and unmodified HSA samples successfully demonstrated the ability of DSC to clearly discern the two HSA preparations and the presence or absence of covalent modifications. DSC thermogram analysis also provided thermodynamic characterization of the different HSA samples of the study, which provided insight into how the two forms of HSA respond to covalent modification with biotin. Consistent with published studies [1] HSA96, the preparation with contaminants that contain globulins and fatty acids seems to be comprised of two forms, HSA96-L and HSA96-H, with HSA96-L more stable than HSA99. The effect of multisite biotinylation is to stabilize HSA96-L and destabilize HSA96-H. Thermodynamic analysis suggests that the binding of ligands comprising the fatty acid and globulin-like contaminant contributes approximately 6.7 kcal/mol to the stability HSA96-L.
{"title":"Effects of Selective Biotinylation on the Thermodynamic Stability of Human Serum Albumin","authors":"H. Hoang, Fidelis Manyanga, M. K. Morakinyo, V. Pinkert, Ferdous Sarwary, Daniel J. Fish, G. Brewood, A. S. Benight","doi":"10.4236/JBPC.2016.71002","DOIUrl":"https://doi.org/10.4236/JBPC.2016.71002","url":null,"abstract":"Thermal denaturation and stability of two commercially available preparations of Human Serum Albumin (HSA), differing in their advertised level of purity, were investigated by differential scanning calorimetry (DSC). These protein samples were 99% pure HSA (termed HSA99) and 96% pure HSA (termed HSA96). According to the supplier, the 3% difference in purity between HSA96 and HSA99 is primarily attributed to the presence of globulins and fatty acids. Our primary aim was to investigate the utility of DSC in discerning changes in HSA that occur when the protein is specifically adducted, and determine how adduct formation manifests itself in HSA denaturation curves, or thermograms, measured by DSC. Effects of site specific covalent attachment of biotin (the adduct) on the thermodynamic stability of HSA were investigated. Each of the HSA preparations was modified by biotinylation targeting a single site, or multiple sites on the protein structure. Thermograms of both modified and unmodified HSA samples successfully demonstrated the ability of DSC to clearly discern the two HSA preparations and the presence or absence of covalent modifications. DSC thermogram analysis also provided thermodynamic characterization of the different HSA samples of the study, which provided insight into how the two forms of HSA respond to covalent modification with biotin. Consistent with published studies [1] HSA96, the preparation with contaminants that contain globulins and fatty acids seems to be comprised of two forms, HSA96-L and HSA96-H, with HSA96-L more stable than HSA99. The effect of multisite biotinylation is to stabilize HSA96-L and destabilize HSA96-H. Thermodynamic analysis suggests that the binding of ligands comprising the fatty acid and globulin-like contaminant contributes approximately 6.7 kcal/mol to the stability HSA96-L.","PeriodicalId":62927,"journal":{"name":"生物物理化学(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70904611","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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