Pub Date : 2013-02-28DOI: 10.15866/IREBIC.V4I1.1580
N. Sahraoui, A. Tamrabet, M. Abdedaim, F. Hamriche
Lead pollution is a global problem, currently under a general awareness. Recent research has confirmed the impact of this pollutant in exposed organisms. Emission sources of lead are multiples and more particularly the emissions of exhaust gases of vehicles because of its use as Tetraethyl lead Pb (C2H5)4 was the main constituent of antiknock agents added to gasoline to increase the octane rating. Knowing that exposure to lead causes lead poisoning, the reflection on the modalities of detoxification needed. It is in this vein that we try to offer our looking for away to detoxification by means of the interaction between lead and iron on one side and lead and zinc of another side of the plant in vitro “PHASEOLUS VULGARIS”. In order to determine the most reliable results in terms of limitations of the toxic effects of lead exposure on the plant in other words antagonism. The choice of iron and zinc is justified by their biological role, in addition they are desired item
{"title":"Optimization Tests of Antagonistic Interaction between Lead / Iron and Lead / Zinc, IN-VITRO Investigations on the Plant: PHASEOLUS VULGARIS","authors":"N. Sahraoui, A. Tamrabet, M. Abdedaim, F. Hamriche","doi":"10.15866/IREBIC.V4I1.1580","DOIUrl":"https://doi.org/10.15866/IREBIC.V4I1.1580","url":null,"abstract":"Lead pollution is a global problem, currently under a general awareness. Recent research has confirmed the impact of this pollutant in exposed organisms. Emission sources of lead are multiples and more particularly the emissions of exhaust gases of vehicles because of its use as Tetraethyl lead Pb (C2H5)4 was the main constituent of antiknock agents added to gasoline to increase the octane rating. Knowing that exposure to lead causes lead poisoning, the reflection on the modalities of detoxification needed. It is in this vein that we try to offer our looking for away to detoxification by means of the interaction between lead and iron on one side and lead and zinc of another side of the plant in vitro “PHASEOLUS VULGARIS”. In order to determine the most reliable results in terms of limitations of the toxic effects of lead exposure on the plant in other words antagonism. The choice of iron and zinc is justified by their biological role, in addition they are desired item","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"3 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2013-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78007856","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 : 2013-01-01DOI: 10.15866/IREBIC.V4I4.1651
N. Acaralı, E. Derun, N. Tugrul, M. Piskin
The purpose of this study is to increase efficiency and to reduce costs by changing the process parameters. The synthesis of zinc borate has been carried out with the reaction of zinc oxide and boric acid. In this study, zinc borate production was carried out in aqueous media using commercial zinc borate as seed. Experiments have been carried out in an isolated glass beaker. Temperature is controlled using a digital temperature sensor and magnetic stirrer provides constantly stirring during the reaction. The experiments were performed in the presence of seed and without seed. The samples were filtered and dried at 105°C for 20 h. Dry, fine powdered zinc borate particles were produced under optimised conditions. The resulting high yield were formed utilizing various amounts of seed and high yield was obtained for saturated solution. The effect of varying the concentrations of seed, reaction time, the amount of water on yield have been investigated. As a result, zinc borate was analyzed with X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) and it was observed that the synthesis was carried out successfully
{"title":"The effect of process parameters on yield for zinc borate production","authors":"N. Acaralı, E. Derun, N. Tugrul, M. Piskin","doi":"10.15866/IREBIC.V4I4.1651","DOIUrl":"https://doi.org/10.15866/IREBIC.V4I4.1651","url":null,"abstract":"The purpose of this study is to increase efficiency and to reduce costs by changing the process parameters. The synthesis of zinc borate has been carried out with the reaction of zinc oxide and boric acid. In this study, zinc borate production was carried out in aqueous media using commercial zinc borate as seed. Experiments have been carried out in an isolated glass beaker. Temperature is controlled using a digital temperature sensor and magnetic stirrer provides constantly stirring during the reaction. The experiments were performed in the presence of seed and without seed. The samples were filtered and dried at 105°C for 20 h. Dry, fine powdered zinc borate particles were produced under optimised conditions. The resulting high yield were formed utilizing various amounts of seed and high yield was obtained for saturated solution. The effect of varying the concentrations of seed, reaction time, the amount of water on yield have been investigated. As a result, zinc borate was analyzed with X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) and it was observed that the synthesis was carried out successfully","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"64 1","pages":"139-142"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85752307","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 : 2012-12-31DOI: 10.15866/IREBIC.V3I6.1579
F. Aderibigbe, A. Anozie, L. Adejumo, R. Owolabi
Cassava starch hydrolysis was investigated in this study using malt extract, alpha amylase and glucoamylase. The effects of process variables, namely: temperature, pH and time were studied and optimized for hydrolysis of cassava (Manihot esculenta) flour to glucose syrup. Three levels of process variables were used for the study. The three levels of process variables were: temperature (60, 67 and 74 oC), time (1.5, 2.0 and 2.5 h) and pH (4.5, 5 and 5.5). A polynomial regression model was developed using the experimental data. The results showed that production of reducing sugar was strongly affected by the variation of variables on malt extract, alpha amylase and glucoamylase hydrolysis of cassava starch. The fit of the model was expressed by the coefficient of determination R2 which was found to be 0.987 indicating that 98.7 % of the variability in the response can be explained by the model. The value also indicates that only 1.3% of the total variation is not explained by the model. This shows that equation (2) is a suitable model to describe the response of the experiment pertaining to reducing sugar production. The statistical significance of the model was validated by F-test for analysis of variance (p ≤ 0.05). For malt extract, alpha amylase and glucoamylase hydrolysis, the optimum value of temperature, time and pH were found to be 74 oC; pH 5.5 and time 1.5 h. The maximum reducing sugar production at optimum condition was 268 g/l representing 76.57 % conversion or 76.57 dextrose equivalent (DE)
{"title":"Optimization of Cassava Starch Hydrolysis by Malt Extract, α-Amylase and Glucoamylase","authors":"F. Aderibigbe, A. Anozie, L. Adejumo, R. Owolabi","doi":"10.15866/IREBIC.V3I6.1579","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I6.1579","url":null,"abstract":"Cassava starch hydrolysis was investigated in this study using malt extract, alpha amylase and glucoamylase. The effects of process variables, namely: temperature, pH and time were studied and optimized for hydrolysis of cassava (Manihot esculenta) flour to glucose syrup. Three levels of process variables were used for the study. The three levels of process variables were: temperature (60, 67 and 74 oC), time (1.5, 2.0 and 2.5 h) and pH (4.5, 5 and 5.5). A polynomial regression model was developed using the experimental data. The results showed that production of reducing sugar was strongly affected by the variation of variables on malt extract, alpha amylase and glucoamylase hydrolysis of cassava starch. The fit of the model was expressed by the coefficient of determination R2 which was found to be 0.987 indicating that 98.7 % of the variability in the response can be explained by the model. The value also indicates that only 1.3% of the total variation is not explained by the model. This shows that equation (2) is a suitable model to describe the response of the experiment pertaining to reducing sugar production. The statistical significance of the model was validated by F-test for analysis of variance (p ≤ 0.05). For malt extract, alpha amylase and glucoamylase hydrolysis, the optimum value of temperature, time and pH were found to be 74 oC; pH 5.5 and time 1.5 h. The maximum reducing sugar production at optimum condition was 268 g/l representing 76.57 % conversion or 76.57 dextrose equivalent (DE)","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"50 1","pages":"234-238"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78230821","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 : 2012-12-31DOI: 10.15866/IREBIC.V3I6.1575
S. Panda, U. P. Tripathy
Pulp and paper industries are releasing a lot of effluents in to the environment with far reaching consequences. This has drawn the attention of public and there is a heavy pressure on industries to go for decreasing pollution load in the effluents before their release into water bodies. Amongst all the known methods, oxidation of pulp and paper industry effluents is an effective and easier method for removing colour loads and lowering chemical oxygen demand (COD). In the present work, an attempt has been made to study the different oxidative methods and their ability to reduce pollution load from the effluents of pulp and paper industry. The methods include ozonation (in absence and presence of catalyst like TiO2, Fe3+ and ZnO), oxidation in presence of oxygen, hydrogen peroxide, per acetic acid, UV-radiation etc. The elimination of pollutants in the effluents is monitored by the disappearance of colour
{"title":"Oxidative Decomposition of Pollutants of Pulp and Paper Industry Effluents: a Review","authors":"S. Panda, U. P. Tripathy","doi":"10.15866/IREBIC.V3I6.1575","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I6.1575","url":null,"abstract":"Pulp and paper industries are releasing a lot of effluents in to the environment with far reaching consequences. This has drawn the attention of public and there is a heavy pressure on industries to go for decreasing pollution load in the effluents before their release into water bodies. Amongst all the known methods, oxidation of pulp and paper industry effluents is an effective and easier method for removing colour loads and lowering chemical oxygen demand (COD). In the present work, an attempt has been made to study the different oxidative methods and their ability to reduce pollution load from the effluents of pulp and paper industry. The methods include ozonation (in absence and presence of catalyst like TiO2, Fe3+ and ZnO), oxidation in presence of oxygen, hydrogen peroxide, per acetic acid, UV-radiation etc. The elimination of pollutants in the effluents is monitored by the disappearance of colour","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"44 1","pages":"168-172"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87447010","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 : 2012-12-31DOI: 10.15866/IREBIC.V3I1.1548
S. Benyoucef, M. Amrani
In the present study, chemically modified Aleppo pine (Pinus halepensis Miller) sawdust was used for removal of phosphate from water. Biosorbent preparation process included size fractionation, extraction for surface activation, acid prehydrolysis, and treatment with urea. Sorption of phosphate ions onto biosorbent was studied using the batch technique. The effect of different parameters such as contact time, adsorbate concentration, and temperature was investigated. The adsorption kinetics data were best described by the pseudo-second-order rate equation, and equilibrium was achieved after 40 min. The Langmuir and Freundlich equations for describing adsorption equilibrium were applied to data. The constants and correlation coefficients of these isotherm models were calculated and compared. The adsorption isotherms obey the Freundlich equation. The thermodynamic parameters like free energy, enthalpy and entropy changes for the adsorption of phosphate ions have been evaluated and it has been found that the reaction was spontaneous and endothermic in nature. The low value of activated energy of adsorption, 3.088 kJ/mol, indicates that the phosphate ions are easily adsorbed on the sawdust. Results suggest that the prepared chemically modified Aleppo pine sawdust has potential in remediation of contaminated waters by phosphate
{"title":"Chemically Modified Biosorbent for Phosphorus Removal from Aqueous Solution","authors":"S. Benyoucef, M. Amrani","doi":"10.15866/IREBIC.V3I1.1548","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I1.1548","url":null,"abstract":"In the present study, chemically modified Aleppo pine (Pinus halepensis Miller) sawdust was used for removal of phosphate from water. Biosorbent preparation process included size fractionation, extraction for surface activation, acid prehydrolysis, and treatment with urea. Sorption of phosphate ions onto biosorbent was studied using the batch technique. The effect of different parameters such as contact time, adsorbate concentration, and temperature was investigated. The adsorption kinetics data were best described by the pseudo-second-order rate equation, and equilibrium was achieved after 40 min. The Langmuir and Freundlich equations for describing adsorption equilibrium were applied to data. The constants and correlation coefficients of these isotherm models were calculated and compared. The adsorption isotherms obey the Freundlich equation. The thermodynamic parameters like free energy, enthalpy and entropy changes for the adsorption of phosphate ions have been evaluated and it has been found that the reaction was spontaneous and endothermic in nature. The low value of activated energy of adsorption, 3.088 kJ/mol, indicates that the phosphate ions are easily adsorbed on the sawdust. Results suggest that the prepared chemically modified Aleppo pine sawdust has potential in remediation of contaminated waters by phosphate","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"3 1","pages":"8-15"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87359698","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 : 2012-12-31DOI: 10.15866/IREBIC.V3I6.1578
R. Arora, R. Kakkar
Hydroxamic acids, R-CO-NH-OH, are a group of naturally occurring and synthetic weak organic acids, having numerous applications in such diverse fields as analytical chemistry, agriculture, pest control, nuclear fuel processing, and corrosion inhibition. Hydroxamic acids are studied as inhibitors of enzymes, e.g., peroxidases, urease and as siderophores for Fe(III) in microbes. Several hydroxamic acids have been studied, of which benzohydroxamic acid (R = C6H5) has emerged as a potent metal chelator and an efficient enzyme inhibitor. This review focuses on benzohydroxamic acid (BHA) and its derivatives and their applications as potent metal chelators and also as inhibitors of various biologically important enzymes like ribonucleotide reductase, urease and matrix metalloproteinase, to name a few
{"title":"Benzohydroxamic Acid and its Applications: a Review","authors":"R. Arora, R. Kakkar","doi":"10.15866/IREBIC.V3I6.1578","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I6.1578","url":null,"abstract":"Hydroxamic acids, R-CO-NH-OH, are a group of naturally occurring and synthetic weak organic acids, having numerous applications in such diverse fields as analytical chemistry, agriculture, pest control, nuclear fuel processing, and corrosion inhibition. Hydroxamic acids are studied as inhibitors of enzymes, e.g., peroxidases, urease and as siderophores for Fe(III) in microbes. Several hydroxamic acids have been studied, of which benzohydroxamic acid (R = C6H5) has emerged as a potent metal chelator and an efficient enzyme inhibitor. This review focuses on benzohydroxamic acid (BHA) and its derivatives and their applications as potent metal chelators and also as inhibitors of various biologically important enzymes like ribonucleotide reductase, urease and matrix metalloproteinase, to name a few","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"11 1","pages":"212-233"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84591402","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 : 2012-10-31DOI: 10.15866/IREBIC.V3I5.1571
A. Attaelmanan, H. Omar
Tarminalia Brownii is a plant utilized by African tribes to cure a number of ailments. In addition to jaundice, they treat other less serious diseases, by drinking a potion made from the tree bark. Bark samples collected from a T. Brownii tree were dried, and then separated into its three layers. Each layer was crushed into fine powder, and subsequently analyzed using an X-ray analytical microscope. Elemental composition of the bark was determined using X-ray fluorescence spectrometry and the results show the presence of Ca in concentrations larger than 85%, while Ti, Mn, Zn, Br and Sr were present in trace amounts (< 1%)
{"title":"Determining the Elemental Composition of Terminalia Brownii’s Bark Using X-Ray Fluorescence Spectrometry","authors":"A. Attaelmanan, H. Omar","doi":"10.15866/IREBIC.V3I5.1571","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I5.1571","url":null,"abstract":"Tarminalia Brownii is a plant utilized by African tribes to cure a number of ailments. In addition to jaundice, they treat other less serious diseases, by drinking a potion made from the tree bark. Bark samples collected from a T. Brownii tree were dried, and then separated into its three layers. Each layer was crushed into fine powder, and subsequently analyzed using an X-ray analytical microscope. Elemental composition of the bark was determined using X-ray fluorescence spectrometry and the results show the presence of Ca in concentrations larger than 85%, while Ti, Mn, Zn, Br and Sr were present in trace amounts (< 1%)","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"32 4","pages":"144-146"},"PeriodicalIF":0.0,"publicationDate":"2012-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91486984","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 : 2012-10-31DOI: 10.15866/IREBIC.V3I5.1574
R. Kakkar, Neeta Azad, P. Gahlot
The binding modes and binding affinities of a synthetic PDK2 inhibitor, AZ12 (N-{4-[(ethylanilino)sulfonyl]-2-methylphenyl}-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide) and its analogues with the PDK2 receptor are reported in this work. To study the molecular basis of the interaction and affinity of binding of AZ12 and similar compounds, the docking site of AZ12 at the lipoamide binding site has been analyzed in detail. We have applied a flexible docking approach to predict the ‘preferable’ binding structure of the ligands in the lipoyl domain. It is found that most of the ligand is embedded into the hydrophobic part of the protein binding site. A total of 418 structures similar to AZ12 were docked into the receptor grid. All of these, except one, found suitable poses and their docking scores range from -13.19 to -3.37. Our results show that compounds similar to AZ12 bind in PDK2 at the same site and also in a position and orientation very similar to AZ12. We then compared the properties of the top-ranked ligand with those of AZ12. Both were found to have similar shape and HOMO and LUMO energies
{"title":"AZ12 Based Design of PDK2 Inhibitors","authors":"R. Kakkar, Neeta Azad, P. Gahlot","doi":"10.15866/IREBIC.V3I5.1574","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I5.1574","url":null,"abstract":"The binding modes and binding affinities of a synthetic PDK2 inhibitor, AZ12 (N-{4-[(ethylanilino)sulfonyl]-2-methylphenyl}-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide) and its analogues with the PDK2 receptor are reported in this work. To study the molecular basis of the interaction and affinity of binding of AZ12 and similar compounds, the docking site of AZ12 at the lipoamide binding site has been analyzed in detail. We have applied a flexible docking approach to predict the ‘preferable’ binding structure of the ligands in the lipoyl domain. It is found that most of the ligand is embedded into the hydrophobic part of the protein binding site. A total of 418 structures similar to AZ12 were docked into the receptor grid. All of these, except one, found suitable poses and their docking scores range from -13.19 to -3.37. Our results show that compounds similar to AZ12 bind in PDK2 at the same site and also in a position and orientation very similar to AZ12. We then compared the properties of the top-ranked ligand with those of AZ12. Both were found to have similar shape and HOMO and LUMO energies","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"1 1","pages":"163-167"},"PeriodicalIF":0.0,"publicationDate":"2012-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72793058","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 : 2012-10-31DOI: 10.15866/IREBIC.V3I5.1572
Ankit Gupta, Deepti Chaturvedi, R. Mahalakshmi
Cleavage efficiencies of cyanogen bromide (CNBr) are drastically reduced in sequences wherein the methionine residue is succeeded by serine or threonine. Solubility issues associated especially with membrane proteins contribute further to reduced cleavage at Met-Xxx sites. Moreover, prolonged incubations of several hours to days, in highly acidic reaction conditions required for CNBr cleavage, often lead to protein degradation. To circumvent these problems, we have developed a protocol for CNBr cleavage of protein fusions, which is particularly useful for Met-Ser sequences. This protocol facilitates enhanced cleavage efficiencies in short incubation times of 1-2 hours. It incorporates up to 40% acetonitrile in 8M urea, or trace amounts of acetonitrile in 6M guanidine hydrochloride, in the final reaction. We demonstrate the successful application of this protocol for the Met-Ser containing membrane protein fusion OmpX-Om14. Cleavage of the Om14 (the yeast mitochondrial outer membrane protein) from E. coli OmpX (Outer membrane protein X) has provided yields of up to 70% product without detectable degradation levels. The direct use of the cleavage reaction for the rapid and cost-effective purification of Om14 has been shown. Using a database analysis, we discuss the importance of this protocol for several membrane proteins that have Met-Ser sequences
{"title":"Modified CNBr Cleavage Protocol for Efficient Separation of Met-Ser Containing OmpX-Om14 Membrane Protein Fusion","authors":"Ankit Gupta, Deepti Chaturvedi, R. Mahalakshmi","doi":"10.15866/IREBIC.V3I5.1572","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I5.1572","url":null,"abstract":"Cleavage efficiencies of cyanogen bromide (CNBr) are drastically reduced in sequences wherein the methionine residue is succeeded by serine or threonine. Solubility issues associated especially with membrane proteins contribute further to reduced cleavage at Met-Xxx sites. Moreover, prolonged incubations of several hours to days, in highly acidic reaction conditions required for CNBr cleavage, often lead to protein degradation. To circumvent these problems, we have developed a protocol for CNBr cleavage of protein fusions, which is particularly useful for Met-Ser sequences. This protocol facilitates enhanced cleavage efficiencies in short incubation times of 1-2 hours. It incorporates up to 40% acetonitrile in 8M urea, or trace amounts of acetonitrile in 6M guanidine hydrochloride, in the final reaction. We demonstrate the successful application of this protocol for the Met-Ser containing membrane protein fusion OmpX-Om14. Cleavage of the Om14 (the yeast mitochondrial outer membrane protein) from E. coli OmpX (Outer membrane protein X) has provided yields of up to 70% product without detectable degradation levels. The direct use of the cleavage reaction for the rapid and cost-effective purification of Om14 has been shown. Using a database analysis, we discuss the importance of this protocol for several membrane proteins that have Met-Ser sequences","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"106 1","pages":"147-156"},"PeriodicalIF":0.0,"publicationDate":"2012-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76133232","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 : 2012-10-31DOI: 10.15866/IREBIC.V3I5.1569
H. Abdallah, S. S. Ali
Thermodynamic behavior of quaternary system with one low molecular weight component; N –Methylpyrrolidone (NMP) as a solvent, non-solvent; polyethylene glycol (PEG 400) and two high molecular weight polymers; polyethersulfone (PES) and cellulose acetate (CA) was investigated. An extended modified Flory-Huggins model was used. The predicted results from model of critical temperature for superiority properties of polymer blend solution were in range between UCST 323 K and LCST 350 K. However, the increasing the vaporization time of PES/CA blend membrane to 30 min has increased the heat of vaporization to 133659.6 J/mole which led to increase in cohesive energy density to 1311.82 J/cm3 and gained more solvent evaporation. The diffusion model was studied on the immersion precipitation process which was indicated that solvent and non-solvent volume fractions increased with time in the coagulation bath , while the polymer solution volume fraction decreased due to solvent and non-solvent removal from polymer solution and blend membrane formation. The predicted results from model of heat treatment process on blend membrane were indicated that increasing in membrane thickness and formation of dense layer in blend membrane
{"title":"Thermodynamic Modeling of PES/CA Blend Membrane Preparation","authors":"H. Abdallah, S. S. Ali","doi":"10.15866/IREBIC.V3I5.1569","DOIUrl":"https://doi.org/10.15866/IREBIC.V3I5.1569","url":null,"abstract":"Thermodynamic behavior of quaternary system with one low molecular weight component; N –Methylpyrrolidone (NMP) as a solvent, non-solvent; polyethylene glycol (PEG 400) and two high molecular weight polymers; polyethersulfone (PES) and cellulose acetate (CA) was investigated. An extended modified Flory-Huggins model was used. The predicted results from model of critical temperature for superiority properties of polymer blend solution were in range between UCST 323 K and LCST 350 K. However, the increasing the vaporization time of PES/CA blend membrane to 30 min has increased the heat of vaporization to 133659.6 J/mole which led to increase in cohesive energy density to 1311.82 J/cm3 and gained more solvent evaporation. The diffusion model was studied on the immersion precipitation process which was indicated that solvent and non-solvent volume fractions increased with time in the coagulation bath , while the polymer solution volume fraction decreased due to solvent and non-solvent removal from polymer solution and blend membrane formation. The predicted results from model of heat treatment process on blend membrane were indicated that increasing in membrane thickness and formation of dense layer in blend membrane","PeriodicalId":14377,"journal":{"name":"International Review of Biophysical Chemistry","volume":"19 1","pages":"125-135"},"PeriodicalIF":0.0,"publicationDate":"2012-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78389461","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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