Pub Date : 2012-07-01DOI: 10.15866/IREBIC.V3I3.1559
D. Coêlho, L. G. Spir, Letícia Celia de Lencastre Novaes, P. Mazzola, E. Silveira, E. Tambourgi, A. Pessoa
This work evaluates a single step purification of bromelain using a PEG/Ammonium Sulphate integrated aqueous two-phase systems (ATPS). This new process integrates the ammonium sulphate precipitation of unwanted proteins along with purification of target molecule by ATPS. The results, analysed by response surface methodology, showed that higher values of protein yield and enzyme activity recovery could be achieved by desirability optimization. Thus, it was possible to obtain a biological activity recovery over than 87.3% with a purification factor of 11.8 fold, using a system composed by 10.86% PEG 4,000 and 36.21% ammonium sulphate saturation. The purified bromelain showed an increased stability when supplemented with PEG, without any loss of activity after 7 hours of incubation
{"title":"Single Step Purification of Bromelain from Ananas Comosus Residues by PEG/Ammonium Sulphate Integrated Aqueous Two-Phase Systems","authors":"D. Coêlho, L. G. Spir, Letícia Celia de Lencastre Novaes, P. Mazzola, E. Silveira, E. Tambourgi, A. Pessoa","doi":"10.15866/IREBIC.V3I3.1559","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I3.1559","url":null,"abstract":"This work evaluates a single step purification of bromelain using a PEG/Ammonium Sulphate integrated aqueous two-phase systems (ATPS). This new process integrates the ammonium sulphate precipitation of unwanted proteins along with purification of target molecule by ATPS. The results, analysed by response surface methodology, showed that higher values of protein yield and enzyme activity recovery could be achieved by desirability optimization. Thus, it was possible to obtain a biological activity recovery over than 87.3% with a purification factor of 11.8 fold, using a system composed by 10.86% PEG 4,000 and 36.21% ammonium sulphate saturation. The purified bromelain showed an increased stability when supplemented with PEG, without any loss of activity after 7 hours of incubation","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"46 1","pages":"55-60"},"PeriodicalIF":0.0,"publicationDate":"2012-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77578979","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}
Pub Date : 2012-07-01DOI: 10.15866/IREBIC.V3I3.1557
A. Pandey, Shashank Kumar
Present study reports the biochemical and antibacterial activities of phytoconstituents present in roots of non toxic weed S. xanthocarpum. Total phenolic contents were quantified in different fractions. Ethanolic (ET) fraction was richest (194.44±0.41 mgPGE/g) followed by ethyl acetate (EA) and aqueous (AQ) fractions (115±0.25 and 88.75± mgPGE/g, respectively). Antioxidant activity was evaluated using reducing power assay (RPA) while lipo-protective activity was determined by lipid peroxidation inhibition (LPOI)/TBARS assays in rat kidney tissue. ET, AQ and HX (hexane) fractions demonstrated significant reducing power at 1000 µg/ml concentration showing dose dependent response in the range 200-1000 µg/ml. ET and AQ fractions exhibited 52% and 45% LPOI, respectively in TBARS assay. Positive correlation was observed between total phenol and RPA (r2=0.399) as well as %LPOI (r2=0.540). Similarly relationship between RPA and %LPOI was also found to be positive (r2=0.379). Pathogenic bacteria Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumonia and Staphylococcus aureus exhibited resistance against AQ fraction in disc diffusion assay
{"title":"Antioxidant, Lipo-Protective and Antibacterial Activities of Phytoconstituents Present in Solanum Xanthocarpum Root","authors":"A. Pandey, Shashank Kumar","doi":"10.15866/IREBIC.V3I3.1557","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I3.1557","url":null,"abstract":"Present study reports the biochemical and antibacterial activities of phytoconstituents present in roots of non toxic weed S. xanthocarpum. Total phenolic contents were quantified in different fractions. Ethanolic (ET) fraction was richest (194.44±0.41 mgPGE/g) followed by ethyl acetate (EA) and aqueous (AQ) fractions (115±0.25 and 88.75± mgPGE/g, respectively). Antioxidant activity was evaluated using reducing power assay (RPA) while lipo-protective activity was determined by lipid peroxidation inhibition (LPOI)/TBARS assays in rat kidney tissue. ET, AQ and HX (hexane) fractions demonstrated significant reducing power at 1000 µg/ml concentration showing dose dependent response in the range 200-1000 µg/ml. ET and AQ fractions exhibited 52% and 45% LPOI, respectively in TBARS assay. Positive correlation was observed between total phenol and RPA (r2=0.399) as well as %LPOI (r2=0.540). Similarly relationship between RPA and %LPOI was also found to be positive (r2=0.379). Pathogenic bacteria Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumonia and Staphylococcus aureus exhibited resistance against AQ fraction in disc diffusion assay","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"1 1","pages":"42-47"},"PeriodicalIF":0.0,"publicationDate":"2012-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88901556","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}
Pub Date : 2012-04-30DOI: 10.15866/IREBIC.V3I2.1551
N. K. Burlova-Vasilieva, O. Savchuk, L. Ostapchenko
This paper describes the purification of fibrino(geno)lytic enzymes from Agkistrodon blomhoffii ussuriensis venom in three chromatographic stages. Two single-stranded enzymes with molecular weight of 30 and 37 kDa were separated. Both toxins were purified using affinity, hydrophobic interaction and ion-exchange chromatography and were identified as metaloproteinase and serine protease respectively
{"title":"Isolation and Purification of Fibrino(geno)lytic Enzymes from Agkistrodon Blomhoffi Usuriensis Venom","authors":"N. K. Burlova-Vasilieva, O. Savchuk, L. Ostapchenko","doi":"10.15866/IREBIC.V3I2.1551","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I2.1551","url":null,"abstract":"This paper describes the purification of fibrino(geno)lytic enzymes from Agkistrodon blomhoffii ussuriensis venom in three chromatographic stages. Two single-stranded enzymes with molecular weight of 30 and 37 kDa were separated. Both toxins were purified using affinity, hydrophobic interaction and ion-exchange chromatography and were identified as metaloproteinase and serine protease respectively","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"99 1","pages":"20-23"},"PeriodicalIF":0.0,"publicationDate":"2012-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75226865","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}
Pub Date : 2012-04-30DOI: 10.15866/IREBIC.V3I2.1554
T. Silva, I. P. Bresolin, G. Takaki, Hiroshi Aoyma, I. Garrard, E. Tambourgi
Ananas erectifolius (curaua) is a fibrous vegetable that can be found in North region of Brazil. It has physico-chemical features that provide great potential in the automobile industry as a source of fibers. In addition, from the same plant, the development of new extraction and purification processes for bromelain have been studied. To optimise this process, it is necessary to investigate enzyme stability, so that bromelain retains its biological activity when stored, isolated, purified or subjected to any other manipulation, such as autodigestion, proteolytic enzymes and heating. This study aimed to evaluate the activity of the enzyme bromelain extracted from the leaves of curaua, white and purple, and study its stability. The proteolytic activity was measured for each of the tests by the azocasein method. The stability study to pH and temperature was accomplished by the enzyme activity after storage at 4°C and -18°C, compared with the lyophilized crude extract, over a period of 30 days. The samples were subjected to different conditions for a period of 60 minutes and then the remaining bromelain activity was measured. Results showed that bromelain extracted from lyophilized curaua provided better stability and a higher enzymatic activity, and was also more stable at 20°C, losing only 5% of its activity
{"title":"Study of Enzyme Activity and Stability to pH and Temperature of Bromelain Extracted from Curaua (Ananas erectifolius L. B. SMITH) Purple and White","authors":"T. Silva, I. P. Bresolin, G. Takaki, Hiroshi Aoyma, I. Garrard, E. Tambourgi","doi":"10.15866/IREBIC.V3I2.1554","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I2.1554","url":null,"abstract":"Ananas erectifolius (curaua) is a fibrous vegetable that can be found in North region of Brazil. It has physico-chemical features that provide great potential in the automobile industry as a source of fibers. In addition, from the same plant, the development of new extraction and purification processes for bromelain have been studied. To optimise this process, it is necessary to investigate enzyme stability, so that bromelain retains its biological activity when stored, isolated, purified or subjected to any other manipulation, such as autodigestion, proteolytic enzymes and heating. This study aimed to evaluate the activity of the enzyme bromelain extracted from the leaves of curaua, white and purple, and study its stability. The proteolytic activity was measured for each of the tests by the azocasein method. The stability study to pH and temperature was accomplished by the enzyme activity after storage at 4°C and -18°C, compared with the lyophilized crude extract, over a period of 30 days. The samples were subjected to different conditions for a period of 60 minutes and then the remaining bromelain activity was measured. Results showed that bromelain extracted from lyophilized curaua provided better stability and a higher enzymatic activity, and was also more stable at 20°C, losing only 5% of its activity","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"1 1","pages":"31-35"},"PeriodicalIF":0.0,"publicationDate":"2012-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82587026","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}
Pub Date : 2012-04-30DOI: 10.15866/IREBIC.V3I2.1552
F. S. Kok, I. Muhamad, Chew-Tin Lee, F. Razali, N. Pa’e, S. Shaharuddin
This study investigated the effects of pH and temperature on the growth and β-glucosidase activity of Lactobacillus rhamnosus NRRL 442 during anaerobic fermentation. Initially, the β-glucosidase activity of the cell harvested from shake flask culture was characterized. The result indicated the cell exhibited the highest specific β-glucosidase activity (1.7990±0.0096 UE mg-1 DCM) at pH 6.5 and 46oC. Subsequently, the effect of fermentation pH (range: 4.5-6.5) on cell growth and β-glucosidase activity was investigated in 2-L bioreactor. Cell suppression due to acidity (pH 4.5) was observed in fermentation with controlled and uncontrolled pH. Significant improvement of cell growth was found at higher pH (5.5-6.5). The cell exhibited the highest growth rate at pH 6 and highest β-glucosidase activity (30.09 ± 0.16 UE, 4.16 times β-glucosidase activity in uncontrolled fermentation). The optimum temperature for the fermentation in bioreactor was found to be 40oC for cell growth and β-glucosidase activity. All profiles including studies on effect of pH and temperature indicated that the cells exhibited higher β-glucosidase activity at higher growth rate. In addition, a short period of starvation (3h) enhanced the β-glucosidase activity of the cell under all studied conditions except for fermentation where cell growth was suppressed due to acidity
{"title":"Effects of pH and Temperature on the Growth and β-Glucosidase Activity of Lactobacillus Rhamnosus NRRL 442 in Anaerobic Fermentation","authors":"F. S. Kok, I. Muhamad, Chew-Tin Lee, F. Razali, N. Pa’e, S. Shaharuddin","doi":"10.15866/IREBIC.V3I2.1552","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I2.1552","url":null,"abstract":"This study investigated the effects of pH and temperature on the growth and β-glucosidase activity of Lactobacillus rhamnosus NRRL 442 during anaerobic fermentation. Initially, the β-glucosidase activity of the cell harvested from shake flask culture was characterized. The result indicated the cell exhibited the highest specific β-glucosidase activity (1.7990±0.0096 UE mg-1 DCM) at pH 6.5 and 46oC. Subsequently, the effect of fermentation pH (range: 4.5-6.5) on cell growth and β-glucosidase activity was investigated in 2-L bioreactor. Cell suppression due to acidity (pH 4.5) was observed in fermentation with controlled and uncontrolled pH. Significant improvement of cell growth was found at higher pH (5.5-6.5). The cell exhibited the highest growth rate at pH 6 and highest β-glucosidase activity (30.09 ± 0.16 UE, 4.16 times β-glucosidase activity in uncontrolled fermentation). The optimum temperature for the fermentation in bioreactor was found to be 40oC for cell growth and β-glucosidase activity. All profiles including studies on effect of pH and temperature indicated that the cells exhibited higher β-glucosidase activity at higher growth rate. In addition, a short period of starvation (3h) enhanced the β-glucosidase activity of the cell under all studied conditions except for fermentation where cell growth was suppressed due to acidity","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"42 1","pages":"24-30"},"PeriodicalIF":0.0,"publicationDate":"2012-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77260317","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}
Pub Date : 2012-04-30DOI: 10.15866/IREBIC.V3I2.1555
G. S. Padilha, R. Alegre, E. Tambourgi
In this work, for enzyme production, the Burkholderia cepacia was grown in medium containing salts, yeast extract, bacteriological peptone and 6% soybean oil, liquid fermentation in bioreactor type Bioflo III. After 96 hours, the supernatant was separated from the cells by centrifugation and it was used as enzyme extract. The enzyme was immobilized by ionic gelation using sodium alginate and calcium chloride. For the encapsulation, a factorial design 22 was made with 2 and 0.5 mm atomizer sizes and CaCl2 (2 and 4% w/v) concentration. Subsequently, the encapsulate enzyme was characterized as to its encapsulation efficiency, stability, size and distribution size, and morphology
{"title":"Study of Morphology, Estability and Structure of Burkholderia cepacia Lipase with Alginate Gels","authors":"G. S. Padilha, R. Alegre, E. Tambourgi","doi":"10.15866/IREBIC.V3I2.1555","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I2.1555","url":null,"abstract":"In this work, for enzyme production, the Burkholderia cepacia was grown in medium containing salts, yeast extract, bacteriological peptone and 6% soybean oil, liquid fermentation in bioreactor type Bioflo III. After 96 hours, the supernatant was separated from the cells by centrifugation and it was used as enzyme extract. The enzyme was immobilized by ionic gelation using sodium alginate and calcium chloride. For the encapsulation, a factorial design 22 was made with 2 and 0.5 mm atomizer sizes and CaCl2 (2 and 4% w/v) concentration. Subsequently, the encapsulate enzyme was characterized as to its encapsulation efficiency, stability, size and distribution size, and morphology","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"1 1","pages":"36-41"},"PeriodicalIF":0.0,"publicationDate":"2012-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91111023","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}
Pub Date : 2012-02-29DOI: 10.15866/IREBIC.V3I1.1550
K. Venkatramanan
Ultrasonic study has become an important research tool in the field of polymers for investigating the structure and molecular interactions in multi component system. Ultrasonic studies were carried out on Polyethylene glycol (PEG 1000) at different concentrations (0-1%) in toluene at 303K. Ultrasonic parameters like adiabatic compressibility, free volume and internal pressure were calculated. The ultrasonic velocity decreases with increase in concentration. The effect of concentration is analyzed. An attempt has been made to blend PEG 1000 with PPG 1000 at 303K at various compositions 1:0, 0.8:0.2, 0.6:0.4, 0.5:0.5, 0.4:0.6, 0.2:0.8, 0:1 and the miscibility nature of the blend is analyzed through ultrasonic technique. The variation of ultrasonic velocity with blend composition is nonlinear and follows S-type pattern, which shows that the blend is immiscible. The miscibility nature of the blend is further confirmed through other techniques like viscosity and refractive index studies
{"title":"A Study on the Molecular Interaction of PEG 1000 and its Blend in Toluene Using Ultrasonic Technique","authors":"K. Venkatramanan","doi":"10.15866/IREBIC.V3I1.1550","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I1.1550","url":null,"abstract":"Ultrasonic study has become an important research tool in the field of polymers for investigating the structure and molecular interactions in multi component system. Ultrasonic studies were carried out on Polyethylene glycol (PEG 1000) at different concentrations (0-1%) in toluene at 303K. Ultrasonic parameters like adiabatic compressibility, free volume and internal pressure were calculated. The ultrasonic velocity decreases with increase in concentration. The effect of concentration is analyzed. An attempt has been made to blend PEG 1000 with PPG 1000 at 303K at various compositions 1:0, 0.8:0.2, 0.6:0.4, 0.5:0.5, 0.4:0.6, 0.2:0.8, 0:1 and the miscibility nature of the blend is analyzed through ultrasonic technique. The variation of ultrasonic velocity with blend composition is nonlinear and follows S-type pattern, which shows that the blend is immiscible. The miscibility nature of the blend is further confirmed through other techniques like viscosity and refractive index studies","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"36 1","pages":"16-19"},"PeriodicalIF":0.0,"publicationDate":"2012-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88867549","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}
Pub Date : 2012-02-29DOI: 10.15866/IREBIC.V3I1.1547
Nadiem Anwar, A. Widjaja, S. Winardi
The study of the enzymatic hydrolysis of alkaline-pretreated rice straw was conducted using mixture of cellulases produced from Trichoderma reesei and from Aspergillus niger. 2 % NaOH was found effective in reducing the lignin content in rice straw as evidenced from quantitative data and confirmed by the SEM image. The enzymatic hydrolysis was performed at pH 5.5 and 40 oC, a condition which was determined upon compromising between the optimum values of pH and temperature and the enzyme stability. The mixture of crude cellulases was able to give higher conversion than cellulase from one source of fungi and also higher than the conversion using pure commercial cellulase from A. niger. Addition of 1 U activity of crude cellulase from A. niger to every 2 U activity of crude cellulase from T. reesei at 0.47 U/mL enzyme activity increased the concentration of reducing sugar by about 16%
{"title":"Study of the Enzymatic Hydrolysis of Alkaline-Pretreated Rice Straw Using Cellulase of Various Sources and Compositions","authors":"Nadiem Anwar, A. Widjaja, S. Winardi","doi":"10.15866/IREBIC.V3I1.1547","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I1.1547","url":null,"abstract":"The study of the enzymatic hydrolysis of alkaline-pretreated rice straw was conducted using mixture of cellulases produced from Trichoderma reesei and from Aspergillus niger. 2 % NaOH was found effective in reducing the lignin content in rice straw as evidenced from quantitative data and confirmed by the SEM image. The enzymatic hydrolysis was performed at pH 5.5 and 40 oC, a condition which was determined upon compromising between the optimum values of pH and temperature and the enzyme stability. The mixture of crude cellulases was able to give higher conversion than cellulase from one source of fungi and also higher than the conversion using pure commercial cellulase from A. niger. Addition of 1 U activity of crude cellulase from A. niger to every 2 U activity of crude cellulase from T. reesei at 0.47 U/mL enzyme activity increased the concentration of reducing sugar by about 16%","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"6 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2012-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85321950","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}
Pub Date : 2012-01-01DOI: 10.15866/IREBIC.V3I6.1576
Soma Banerjee, S. Pal
We present femtosecond to nanosecond-resolved studies of the dynamics of aqueous solvation within self-assembled dimeric structure of caffeine molecules. We have extended our studies in various temperatures in order to explore structural evolution of the self assemblies and consequently the dynamics of solvation in the interior of the dimer. Furthermore, we report a systematic investigation of caffeine induced dissociation of ethidium (Et) cation, a potential mutagen from nucleic acids and biomimetic systems. Time-resolved fluorescence studies are consistent with a mechanism where caffeine-Et complex formation in bulk solution drives the dissociation of DNA-bound Et. Temperature dependent picosecond resolved studies show the caffeine-Et complex to be stable over a wide range of temperature, within and beyond the normal physiological limit. A combination of NMR spectroscopy and DLS experiments allowed us to propose a molecular model of caffeine-Et complex. Caffeine induced extraction of Et from whole cells were also performed on squamous epithelial cells collected from the inner lining of the human mouth, A549 (lung carcinoma), A375 (human skin), RAW (macrophage) and Vero (African green monkey kidney epithelium) cell lines. Interestingly, the efficiency of caffeine in extracting Et has been found to be dependent on cell types. Our steady state and picosecond resolved spectroscopic studies on the detachment of Et from various biomimicking micelles of different charges reveal the specificity of caffeine molecule for carrying out such dissociation. The picosecond resolved Forster resonance energy transfer (FRET) studies between a DNA minor groove binder dye Hoeschst 33258 (H258, donor) and Et (acceptor) have been employed to investigate the alteration in their association in presence of caffeine in the molecular level. Finally, our fluorescence micrographs of epithelial cells validate the alteration of FRET efficiency between the donor and the acceptor due to the caffeine mediated release of the latter. Our results both in-vitro as well as ex-vivo provide important clues about efficiency and role of caffeine as a potential anti-mutagenic therapeutic agent
{"title":"Caffeine Mediated Dissociation of a Potential Mutagen from DNA Mimetics, DNA and Cellular Nuclei: Ultrafast Spectroscopic Studies","authors":"Soma Banerjee, S. Pal","doi":"10.15866/IREBIC.V3I6.1576","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I6.1576","url":null,"abstract":"We present femtosecond to nanosecond-resolved studies of the dynamics of aqueous solvation within self-assembled dimeric structure of caffeine molecules. We have extended our studies in various temperatures in order to explore structural evolution of the self assemblies and consequently the dynamics of solvation in the interior of the dimer. Furthermore, we report a systematic investigation of caffeine induced dissociation of ethidium (Et) cation, a potential mutagen from nucleic acids and biomimetic systems. Time-resolved fluorescence studies are consistent with a mechanism where caffeine-Et complex formation in bulk solution drives the dissociation of DNA-bound Et. Temperature dependent picosecond resolved studies show the caffeine-Et complex to be stable over a wide range of temperature, within and beyond the normal physiological limit. A combination of NMR spectroscopy and DLS experiments allowed us to propose a molecular model of caffeine-Et complex. Caffeine induced extraction of Et from whole cells were also performed on squamous epithelial cells collected from the inner lining of the human mouth, A549 (lung carcinoma), A375 (human skin), RAW (macrophage) and Vero (African green monkey kidney epithelium) cell lines. Interestingly, the efficiency of caffeine in extracting Et has been found to be dependent on cell types. Our steady state and picosecond resolved spectroscopic studies on the detachment of Et from various biomimicking micelles of different charges reveal the specificity of caffeine molecule for carrying out such dissociation. The picosecond resolved Forster resonance energy transfer (FRET) studies between a DNA minor groove binder dye Hoeschst 33258 (H258, donor) and Et (acceptor) have been employed to investigate the alteration in their association in presence of caffeine in the molecular level. Finally, our fluorescence micrographs of epithelial cells validate the alteration of FRET efficiency between the donor and the acceptor due to the caffeine mediated release of the latter. Our results both in-vitro as well as ex-vivo provide important clues about efficiency and role of caffeine as a potential anti-mutagenic therapeutic agent","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"111 1","pages":"173-204"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86786966","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}
Pub Date : 2012-01-01DOI: 10.15866/IREBIC.V3I5.1570
G. Yadav, Somnath Shinde
Microwave irradiation and biocatalysis are important and rapidly developing technologies in green and sustainable engineering. The synergistic effect of microwave irradiation and lipase catalysis in transesterification of ethyl (2E)-3-phenylprop-2-enoate and 4,8-dimethylnon-7-en-1-ol was studied using immobilized enzymes such as Novozym 435, Lipase AYS amino, Lipozyme RMIM and Lipozyme TL IM. Novozym 435 was the best catalyst amongst studied. The effects of various parameters affecting the conversion and initial rates of transesterification were studied to establish kinetics and mechanism. There is synergism between enzyme catalysis and microwave irradiation, an increase in initial rates up to 2.3-fold was observed under microwave irradiation than that under conventional heating. With a substrate concentration of 0.03333 kmol/m3 of ethyl (2E)-3-phenylprop-2-enoate and 0.06667 kmol/m3 of 4,8-dimethylnon-7-en-1-ol in n-heptane, Novozym 435 offered a conversion of 94 % at 333 K in 21600 s. The analysis of initial rate data and progress curve data showed that the reaction obeys ternary complex ordered bi–bi mechanism with inhibition by 4,8-dimethylnon-7-en-1-ol. The theoretical predictions and experimental data match very well. These studies were also extended to other alcohols viz, n-butanol, n-pentanol, (3Z)-4,8-dimethylnon-3,7-dien-1-ol, benzyl alcohol, isoamyl alcohol, glycidol and 1,4-butanediol
{"title":"Synergism of Microwave Irradiation and Immobilized Lipase Catalysis in Synthesis of 4,8-dimethylnon-7-en-1yl (2E)-3-phenylpro-2-enolate","authors":"G. Yadav, Somnath Shinde","doi":"10.15866/IREBIC.V3I5.1570","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I5.1570","url":null,"abstract":"Microwave irradiation and biocatalysis are important and rapidly developing technologies in green and sustainable engineering. The synergistic effect of microwave irradiation and lipase catalysis in transesterification of ethyl (2E)-3-phenylprop-2-enoate and 4,8-dimethylnon-7-en-1-ol was studied using immobilized enzymes such as Novozym 435, Lipase AYS amino, Lipozyme RMIM and Lipozyme TL IM. Novozym 435 was the best catalyst amongst studied. The effects of various parameters affecting the conversion and initial rates of transesterification were studied to establish kinetics and mechanism. There is synergism between enzyme catalysis and microwave irradiation, an increase in initial rates up to 2.3-fold was observed under microwave irradiation than that under conventional heating. With a substrate concentration of 0.03333 kmol/m3 of ethyl (2E)-3-phenylprop-2-enoate and 0.06667 kmol/m3 of 4,8-dimethylnon-7-en-1-ol in n-heptane, Novozym 435 offered a conversion of 94 % at 333 K in 21600 s. The analysis of initial rate data and progress curve data showed that the reaction obeys ternary complex ordered bi–bi mechanism with inhibition by 4,8-dimethylnon-7-en-1-ol. The theoretical predictions and experimental data match very well. These studies were also extended to other alcohols viz, n-butanol, n-pentanol, (3Z)-4,8-dimethylnon-3,7-dien-1-ol, benzyl alcohol, isoamyl alcohol, glycidol and 1,4-butanediol","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"31 1","pages":"136-143"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83000537","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：