A bacterial strain identified as Enterobacter asburiae, based on its 16s rDNA sequence study, was... more A bacterial strain identified as Enterobacter asburiae, based on its 16s rDNA sequence study, was isolated from textile industry effluent of Varanasi, Uttar Pradesh, India. The bacterial strain was able to degrade 98% textile effluent within 60 h at 35 mg/mL of the bacterial biomass under aerobic condition. The maximum textile effluent degradation was recorded at pH 8 and at temperature of 32oC. Ultra violet-visible (UV-Vis) spectrum analysis of the bacterial treated textile effluent showed complete disappearance of the peaks at ~ 630 nm and at ~ 410 nm. Moreover, Fourier Transform Infrared (FTIR) spectroscopy study revealed the presence of new sharp peak at ~ 1403 cm indicating the biodegradation of dye effluent. Besides, the colorlessness of bacterial cells also indicated that E. asburiae had the capacity to decolorize the textile effluent through biodegradation instead of absorption on the surface. Gel-electrophoretic studies showed the presence of low mol wt (10.43 kDa) protein ...
Stability of enzymes is an important parameter for their industrial applicability. Here, we repor... more Stability of enzymes is an important parameter for their industrial applicability. Here, we report successful immobilization of β-amylase (bamyl) from peanut (Arachis hypogaea) onto Graphene oxide-carbon nanotube composite (GO-CNT), Graphene oxide nanosheets (GO) and Iron oxide nanoparticles (FeO). The Box-Behnken Design of Response Surface Methodology (RSM) was used which optimized parameters affecting immobilization and gave 90%, 88% and 71% immobilization efficiency, respectively, for the above matrices. β-Amylase immobilization onto GO-CNT (bamyl@GO-CNT) and FeO(bamyl@FeO), resulted into approximately 70% retention of activity at 65 °C after 100 min of exposure. We used atomic force microscopy (AFM), scanning and transmission electron microscopy (SEM and TEM), Fourier transformed infrared (FT-IR) spectroscopy and fluorescence microscopy for characterization of free and enzyme bound nanostructures (NS). Due to the non-toxic nature of immobilization matrices and simple but elegant...
Acute respiratory distress syndrome (ARDS) contributes substantially to mortality and morbidity i... more Acute respiratory distress syndrome (ARDS) contributes substantially to mortality and morbidity in USA and worldwide. Due to limitations in early diagnostics of ARDS by classical methods, there has been need for discovery of novel methods and biomarkers for its characterization. We present here first high-resolution 1H nuclear magnetic resonance (NMR) metabolic profiling of serum from ARDS patients and non ARDS (NARDS) controls to search for novel biomarkers in blood serum for better diagnostics and prognostics. We have carried out study with serum samples from a total of 45 subjects, which included 26 ARDS patients and 19 NARDS controls. Principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) were performed on 1H NMR spectra of serum for group discrimination between the two. PCA and PLS-DA on 1H NMR spectra of serum clearly discriminated between NARDS control and ARDS diseased samples. In our study, lipid resonances showed major contribution for this separation in loading plots. In order to highlight role of other small molecular weight metabolites, the analysis was also carried out after removing lipids resonances from NMR spectrum. There was significant increase in concentrations of N-acetylglycoproteins (NAC) (p = 0.001), acetoacetate (p = 0.001), lactate (p = 0.001), creatinine (p = 0.003), histidine (p = 0.03), formate (p = 0.04) and aromatic amino acids serum of ARDS patients. Along with small metabolites, lipids play a very important role in this discrimination and can differentiate between two classes. Our study has given new avenue in the metabolic profiling of lung injuries.
Cicer α-galactosidase was immobilized onto chitosan and Amberlite with immobilization efficiency ... more Cicer α-galactosidase was immobilized onto chitosan and Amberlite with immobilization efficiency of 62% and 51%, respectively. Compared to soluble enzyme, immobilized enzyme had a broader operational pH range and thermal stability. Temperature optimum for chitosan immobilized enzyme and Amberlite immobilized enzyme was 70°C, whereas it was 50°C for soluble enzyme. After 120days storage at 4°C chitosan immobilized enzyme retained 54% activity and Amberlite immobilized enzyme showed 32% activity. After using the immobilized enzymes 12 times, chitosan immobilized enzyme showed 52% activity, while Amberlite immobilized enzyme retained 22% activity with pNPGal. The immobilized enzyme exhibited higher K(m) compared to the soluble enzyme. Raffinose family oligosaccharides (RFOs) are mainly responsible for flatulence on taking of soybean derived food products. Immobilized enzyme can be used effectively for the hydrolysis of RFOs. After five runs, chitosan and Amberlite immobilized enzyme retained 53% and 34% activity, respectively with soybean RFOs. The easy availability of enzyme source, ease of its immobilization on matrices, non-toxicity and low cost of matrices, increased stability of immobilized enzyme, and effective hydrolysis of RFOs makes it a suitable product with potential applications at industries.
Prof. O.P. Malhotra is a reputed enzymologist par excellence, who took research in the area of bi... more Prof. O.P. Malhotra is a reputed enzymologist par excellence, who took research in the area of biological catalysis to great heights in India. He had a humble beginning in chemistry and moved over to biochemistry and later to biotechnology with ease. His teaching skills were also always highly appreciated. This article pays respect and admiration to the great human being, the teacher, the researcher who occupies the mind space of many lives he touched. Keywords: O.P. Malhotra; enzymologist of repute in India; Indian biochemist.
Rate studies using phosphoglycerate kinase (PGK)--glyceraldehyde-3-phosphate dehydrogenase (GPDH)... more Rate studies using phosphoglycerate kinase (PGK)--glyceraldehyde-3-phosphate dehydrogenase (GPDH) enzyme pair have been carried out to distinguish between the two mechanisms of intermediate metabolite transfer, namely diffusion through the solvent versus "substrate channelling" within an enzyme-enzyme complex. A procedure has been described for the assay of the rates of PGK-catalysed and the PGK-GPDH coupled reactions at high (saturating) GPDH concentration. With PGKs of rabbit muscle and yeast, the coupled reaction proceeded faster than the PGK-catalysed reaction. At a high salt concentration (0.5 M KCl), where a PGK-GPDH complex is known to dissociate, the two reactions proceeded at almost equal rates. At fixed PGK concentration, the rate of the coupled reaction at high (saturating) GPDH concentration varied with the nature (biological origin) of the latter enzyme. In the presence of 0.5 M KCl, the saturating rate values with different GPDHs were almost equal. The PGK-ca...
Background: β-Amylase (EC 3.2.1.2) is a maltogenic enzyme, which releases β-maltose from the non-... more Background: β-Amylase (EC 3.2.1.2) is a maltogenic enzyme, which releases β-maltose from the non-reducing end of the substrates. The enzyme plays important roles for the production of vaccine, maltiol and maltose rich syrups. Apart from these applications the enzyme protects cells from abiotic as well as oxidative damage. The enzyme is βwell characterized in βplants and microbes and crystal structures of β-amylases βhave been βobtained from sweet potato, soybean and Bacillus cereus. Objective: Find out correlation between structural and functional stability induced by change in pH, temperature and chaotropes. Methods: Activity, intrinsic fluorescence, extrinsic fluorescence, near- and far- ultraviolet circular dichroism spectroscopic measurements were performed. Results: Peaks about 208 nm and 222 nm obtained by near-ultraviolet circular dichroism correspond to α-helix whereas peak at 215 nm shows presence of β-sheet. At pH 2.0, absence of tertiary structures, exposed of hydrophobic...
International Journal of Biological Macromolecules
β-Amylase was immobilized onto GQDs using 3-aminopropyltriethoxysilane and glutaraldehyde. Optimi... more β-Amylase was immobilized onto GQDs using 3-aminopropyltriethoxysilane and glutaraldehyde. Optimization was carried out by Box-Behnken design and binding was confirmed by SEM, AFM, FT-IR and fluorescence microscopy. Predicted optimum immobilization efficiency (88.64%) was very close to actual (87.98%), which confirmed the success of the immobilization process. The immobilized enzyme showed maximum activity at pH 5.0 and 57 °C, whereas Km and Vmax were found to be 6.40 mg/mL and 714.28 μmol/min/mg, respectively. The enzyme retained 75% activity after 12 uses at 30 °C. Increased values of ΔG° ΔH°, half-life and activation energy of the enzyme inactivation (ΔEd) revealed that thermo-stability increases after immobilization and the process followed first-order kinetics (r2 > 0.96). The activation energy of catalysis (ΔEa) and ΔEd for immobilized enzyme were 22.58 and 158.99 ± 1.10 kJ/mol, respectively which revealed that denaturation of the enzyme requires a higher amount of energy rather than catalysis. Thermodynamic and fluorescence spectroscopic studies revealed that the process is non-spontaneous (ΔG > 0) and endothermic (ΔH > 0) and occurred through protein unfolding rather than aggregation (ΔS > 0). Thus increase in thermo-stability of immobilized fenugreek β-amylase and non-toxic nature of GQDs could be exploited for maltose production in beverage, food and pharmaceutical industries.
International Journal of Peptide Research and Therapeutics
Abstract Diabetes mellitus Type 2 happens to be one of the most challenging health concerns in re... more Abstract Diabetes mellitus Type 2 happens to be one of the most challenging health concerns in recent times and has spiked an alarming rise taking it into epidemic category. For management of this epidemic, sulphonylureas have been cornerstone in its treatment. The inefficiency and impairment of insulin to function has been compensated by treatment with anti-hyperglycemic agents (glibenclamide). However, this has been linked with cases of hypoglycemia. In order to rectify this, the present study focuses on development of better drug analogue. Sulphonylurea receptor (SUR1) was modeled with reliable efficiency and confirmed for structural validation. The docking results were strongly supported by molecular dynamics data and molecular mechanics-generalized born surface area (MM-GBSA) calculations. Successful docking of predicted sulphonylurea receptor with designed analogue (C 24 H 26 ClN 3 O 4 S) was illustrated with stronger binding energy (− 8.3 kcal/mol) having seven hydrophobic contacts and two hydrogen bonds (Ile 103 and Leu 116 ) with the receptor protein. In case of SUR1-glibenclamide complex, a binding energy of − 7.1 kcal/mol was contributed from four hydrophobic contacts and three hydrogen bonds. The predicted molecule when scrutinized for pharmacophore and QSAR properties, like polar surface area, molar refractivity, oral bioavailability, solubility, transport across the gut, resistance to blood brain barrier and intestinal absorption, showed values mostly falling in prescribed range. It also highlighted that the inhibitor is non-toxic and non-carcinogenic property. Therefore, C 24 H 26 ClN 3 O 4 S can be used as a better and potent drug for treatment of diabetes Type 2 in comparison to glibenclamide. Graphic Abstract
International journal of biological macromolecules, Jan 3, 2018
β-Amylase from un-germinated seeds of peanut (Arachis hypogaea) was purified to apparent electrop... more β-Amylase from un-germinated seeds of peanut (Arachis hypogaea) was purified to apparent electrophoretic homogeneity with final purification fold of 205 and specific activity of 361μmol/min/mg protein. The enzyme was purified employing simple purification techniques for biochemical characterization. The purified enzyme was identified as β-amylase with Mof 31kDa. The enzyme displayed its optimum catalytic activity at pH5.0 and 60°C with activation energy of 4.5kcal/mol and Q1.2. The enzyme displayed Kand Vvalues, for soluble potato starch of 1.28mg/mL and 363.63μmol/min/mg, respectively. Thermal inactivation of β-amylase at 65°C resulted into first-order kinetics with rate constant 0.0126minand t55min. The enzyme was observed to act on native granular potato starch, which could minimize the high cost occurring from solubilization of starch in industries. Enzyme fractions scavenge 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical, indicating its antioxidative nature. In addition, the...
Highly fluorescent nitrogen doped carbon quantum dots (NCQDs) were synthesized using microwave as... more Highly fluorescent nitrogen doped carbon quantum dots (NCQDs) were synthesized using microwave assisted green method. It was characterized by Transmission Electron Microscopy (TEM), FTIR, UV-Visible absorption and Photoluminiscence (PL) techniques. The NCQDs were immobilized with an enzyme named quinolinate phoshphoribosyl transferase (QPRTase). The NCQDs immobilized by QPRTase was used as a fluorescent bioprobe for the selective detection of endogenous neurotoxin quinolinic acid (QA) whose elevated level in serum is marker of many neurological disorders such as Alzheimer's, Huntington's and HIV associated dementia (HAD) as well as deficiency of vitamin B6. Steady state PL studies were carried out to measure the PL response of the fabricated fluorescent bioprobe as a function of QA concentrations in human serum samples. This probe was found applicable in linear range [3.22-51µM] with the limit of detection ~ 6.51µM. It has desirable sensitivity ~ (0.02340±0.0001) µM-1, excel...
Jack bean urease was immobilized on gelatin beads with the help of glutaraldehyde. The optimum im... more Jack bean urease was immobilized on gelatin beads with the help of glutaraldehyde. The optimum immobilization (67.6%) was obtained at 30mg/ml gelatin concentration, 0.5 mg/bead enzyme protein concentration, 1 % glutaraldehyde and at incubation temperature. The of immobilized urease was approximately 90 days at compared with of 20 days for the soluble urease, under identical condition. The apparent optimum pH shifted from 7.3 to 8.0 when the urease was immobilized. The optimum stability temperature of immobilized urease was found to be while that of soluble urease was . Time-dependent thermal inactivation studies showed monophasic kinetics for soluble urease and immobilized urease at , respectively. The immobilized urease beads stored at showed practically no leaching over a period of 30 days. Here we are presenting an easy and economical way of immobilizing urease on the gelatin beads making it suitable for various applications.
Abstract Present study reports the utilization of molybdenum sulfide nanosheets (MoS 2 -NSs) as a... more Abstract Present study reports the utilization of molybdenum sulfide nanosheets (MoS 2 -NSs) as a novel platform for β -amylase immobilization via glutaraldehyde activation, producing nanobiocatalyst with exotic superiority over the independent enzyme. Confocal microscopy, Fourier transform infrared (FT-IR) spectroscopy, Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) studies demonstrated successful immobilization of β -amylase onto MoS 2 -NSs. Optimizing parameters by Box-Behnken design of Response Surface Methodology, approximately 92% immobilization efficiency was achieved. Thermo-stability, pH stability, reusability and storage stability of immobilized β -amylase were interestingly superior with respect to the soluble enzyme. β -Amylase immobilized onto MoS 2 -NSs exhibited maximum catalytic activity at the same pH and temperature as the soluble enzyme but with broadening in the range of parameters. In addition, the immobilized enzyme retained almost 80% residual activity, even after 10 reuses. Immobilized enzyme had around 83% residual activity upon storage over a period of 50 days. Changes in Michaelis-Menten constant after immobilization, point that some of the active sites of enzyme were inaccessible to substrate due to strained enzyme structure upon immobilization. The results obtained here suggest that the β -amylase-MoS 2 -NSs system could be used in industrial processes permitting broader temperature and pH ranges. Besides, the non-toxic nature of matrix, long-term storage and reusability of nanobiocatalyst could be magnificently used for the production of maltose in food and pharmaceutical industries.
A bacterial strain identified as Enterobacter asburiae, based on its 16s rDNA sequence study, was... more A bacterial strain identified as Enterobacter asburiae, based on its 16s rDNA sequence study, was isolated from textile industry effluent of Varanasi, Uttar Pradesh, India. The bacterial strain was able to degrade 98% textile effluent within 60 h at 35 mg/mL of the bacterial biomass under aerobic condition. The maximum textile effluent degradation was recorded at pH 8 and at temperature of 32oC. Ultra violet-visible (UV-Vis) spectrum analysis of the bacterial treated textile effluent showed complete disappearance of the peaks at ~ 630 nm and at ~ 410 nm. Moreover, Fourier Transform Infrared (FTIR) spectroscopy study revealed the presence of new sharp peak at ~ 1403 cm indicating the biodegradation of dye effluent. Besides, the colorlessness of bacterial cells also indicated that E. asburiae had the capacity to decolorize the textile effluent through biodegradation instead of absorption on the surface. Gel-electrophoretic studies showed the presence of low mol wt (10.43 kDa) protein ...
Stability of enzymes is an important parameter for their industrial applicability. Here, we repor... more Stability of enzymes is an important parameter for their industrial applicability. Here, we report successful immobilization of β-amylase (bamyl) from peanut (Arachis hypogaea) onto Graphene oxide-carbon nanotube composite (GO-CNT), Graphene oxide nanosheets (GO) and Iron oxide nanoparticles (FeO). The Box-Behnken Design of Response Surface Methodology (RSM) was used which optimized parameters affecting immobilization and gave 90%, 88% and 71% immobilization efficiency, respectively, for the above matrices. β-Amylase immobilization onto GO-CNT (bamyl@GO-CNT) and FeO(bamyl@FeO), resulted into approximately 70% retention of activity at 65 °C after 100 min of exposure. We used atomic force microscopy (AFM), scanning and transmission electron microscopy (SEM and TEM), Fourier transformed infrared (FT-IR) spectroscopy and fluorescence microscopy for characterization of free and enzyme bound nanostructures (NS). Due to the non-toxic nature of immobilization matrices and simple but elegant...
Acute respiratory distress syndrome (ARDS) contributes substantially to mortality and morbidity i... more Acute respiratory distress syndrome (ARDS) contributes substantially to mortality and morbidity in USA and worldwide. Due to limitations in early diagnostics of ARDS by classical methods, there has been need for discovery of novel methods and biomarkers for its characterization. We present here first high-resolution 1H nuclear magnetic resonance (NMR) metabolic profiling of serum from ARDS patients and non ARDS (NARDS) controls to search for novel biomarkers in blood serum for better diagnostics and prognostics. We have carried out study with serum samples from a total of 45 subjects, which included 26 ARDS patients and 19 NARDS controls. Principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) were performed on 1H NMR spectra of serum for group discrimination between the two. PCA and PLS-DA on 1H NMR spectra of serum clearly discriminated between NARDS control and ARDS diseased samples. In our study, lipid resonances showed major contribution for this separation in loading plots. In order to highlight role of other small molecular weight metabolites, the analysis was also carried out after removing lipids resonances from NMR spectrum. There was significant increase in concentrations of N-acetylglycoproteins (NAC) (p = 0.001), acetoacetate (p = 0.001), lactate (p = 0.001), creatinine (p = 0.003), histidine (p = 0.03), formate (p = 0.04) and aromatic amino acids serum of ARDS patients. Along with small metabolites, lipids play a very important role in this discrimination and can differentiate between two classes. Our study has given new avenue in the metabolic profiling of lung injuries.
Cicer α-galactosidase was immobilized onto chitosan and Amberlite with immobilization efficiency ... more Cicer α-galactosidase was immobilized onto chitosan and Amberlite with immobilization efficiency of 62% and 51%, respectively. Compared to soluble enzyme, immobilized enzyme had a broader operational pH range and thermal stability. Temperature optimum for chitosan immobilized enzyme and Amberlite immobilized enzyme was 70°C, whereas it was 50°C for soluble enzyme. After 120days storage at 4°C chitosan immobilized enzyme retained 54% activity and Amberlite immobilized enzyme showed 32% activity. After using the immobilized enzymes 12 times, chitosan immobilized enzyme showed 52% activity, while Amberlite immobilized enzyme retained 22% activity with pNPGal. The immobilized enzyme exhibited higher K(m) compared to the soluble enzyme. Raffinose family oligosaccharides (RFOs) are mainly responsible for flatulence on taking of soybean derived food products. Immobilized enzyme can be used effectively for the hydrolysis of RFOs. After five runs, chitosan and Amberlite immobilized enzyme retained 53% and 34% activity, respectively with soybean RFOs. The easy availability of enzyme source, ease of its immobilization on matrices, non-toxicity and low cost of matrices, increased stability of immobilized enzyme, and effective hydrolysis of RFOs makes it a suitable product with potential applications at industries.
Prof. O.P. Malhotra is a reputed enzymologist par excellence, who took research in the area of bi... more Prof. O.P. Malhotra is a reputed enzymologist par excellence, who took research in the area of biological catalysis to great heights in India. He had a humble beginning in chemistry and moved over to biochemistry and later to biotechnology with ease. His teaching skills were also always highly appreciated. This article pays respect and admiration to the great human being, the teacher, the researcher who occupies the mind space of many lives he touched. Keywords: O.P. Malhotra; enzymologist of repute in India; Indian biochemist.
Rate studies using phosphoglycerate kinase (PGK)--glyceraldehyde-3-phosphate dehydrogenase (GPDH)... more Rate studies using phosphoglycerate kinase (PGK)--glyceraldehyde-3-phosphate dehydrogenase (GPDH) enzyme pair have been carried out to distinguish between the two mechanisms of intermediate metabolite transfer, namely diffusion through the solvent versus "substrate channelling" within an enzyme-enzyme complex. A procedure has been described for the assay of the rates of PGK-catalysed and the PGK-GPDH coupled reactions at high (saturating) GPDH concentration. With PGKs of rabbit muscle and yeast, the coupled reaction proceeded faster than the PGK-catalysed reaction. At a high salt concentration (0.5 M KCl), where a PGK-GPDH complex is known to dissociate, the two reactions proceeded at almost equal rates. At fixed PGK concentration, the rate of the coupled reaction at high (saturating) GPDH concentration varied with the nature (biological origin) of the latter enzyme. In the presence of 0.5 M KCl, the saturating rate values with different GPDHs were almost equal. The PGK-ca...
Background: β-Amylase (EC 3.2.1.2) is a maltogenic enzyme, which releases β-maltose from the non-... more Background: β-Amylase (EC 3.2.1.2) is a maltogenic enzyme, which releases β-maltose from the non-reducing end of the substrates. The enzyme plays important roles for the production of vaccine, maltiol and maltose rich syrups. Apart from these applications the enzyme protects cells from abiotic as well as oxidative damage. The enzyme is βwell characterized in βplants and microbes and crystal structures of β-amylases βhave been βobtained from sweet potato, soybean and Bacillus cereus. Objective: Find out correlation between structural and functional stability induced by change in pH, temperature and chaotropes. Methods: Activity, intrinsic fluorescence, extrinsic fluorescence, near- and far- ultraviolet circular dichroism spectroscopic measurements were performed. Results: Peaks about 208 nm and 222 nm obtained by near-ultraviolet circular dichroism correspond to α-helix whereas peak at 215 nm shows presence of β-sheet. At pH 2.0, absence of tertiary structures, exposed of hydrophobic...
International Journal of Biological Macromolecules
β-Amylase was immobilized onto GQDs using 3-aminopropyltriethoxysilane and glutaraldehyde. Optimi... more β-Amylase was immobilized onto GQDs using 3-aminopropyltriethoxysilane and glutaraldehyde. Optimization was carried out by Box-Behnken design and binding was confirmed by SEM, AFM, FT-IR and fluorescence microscopy. Predicted optimum immobilization efficiency (88.64%) was very close to actual (87.98%), which confirmed the success of the immobilization process. The immobilized enzyme showed maximum activity at pH 5.0 and 57 °C, whereas Km and Vmax were found to be 6.40 mg/mL and 714.28 μmol/min/mg, respectively. The enzyme retained 75% activity after 12 uses at 30 °C. Increased values of ΔG° ΔH°, half-life and activation energy of the enzyme inactivation (ΔEd) revealed that thermo-stability increases after immobilization and the process followed first-order kinetics (r2 > 0.96). The activation energy of catalysis (ΔEa) and ΔEd for immobilized enzyme were 22.58 and 158.99 ± 1.10 kJ/mol, respectively which revealed that denaturation of the enzyme requires a higher amount of energy rather than catalysis. Thermodynamic and fluorescence spectroscopic studies revealed that the process is non-spontaneous (ΔG > 0) and endothermic (ΔH > 0) and occurred through protein unfolding rather than aggregation (ΔS > 0). Thus increase in thermo-stability of immobilized fenugreek β-amylase and non-toxic nature of GQDs could be exploited for maltose production in beverage, food and pharmaceutical industries.
International Journal of Peptide Research and Therapeutics
Abstract Diabetes mellitus Type 2 happens to be one of the most challenging health concerns in re... more Abstract Diabetes mellitus Type 2 happens to be one of the most challenging health concerns in recent times and has spiked an alarming rise taking it into epidemic category. For management of this epidemic, sulphonylureas have been cornerstone in its treatment. The inefficiency and impairment of insulin to function has been compensated by treatment with anti-hyperglycemic agents (glibenclamide). However, this has been linked with cases of hypoglycemia. In order to rectify this, the present study focuses on development of better drug analogue. Sulphonylurea receptor (SUR1) was modeled with reliable efficiency and confirmed for structural validation. The docking results were strongly supported by molecular dynamics data and molecular mechanics-generalized born surface area (MM-GBSA) calculations. Successful docking of predicted sulphonylurea receptor with designed analogue (C 24 H 26 ClN 3 O 4 S) was illustrated with stronger binding energy (− 8.3 kcal/mol) having seven hydrophobic contacts and two hydrogen bonds (Ile 103 and Leu 116 ) with the receptor protein. In case of SUR1-glibenclamide complex, a binding energy of − 7.1 kcal/mol was contributed from four hydrophobic contacts and three hydrogen bonds. The predicted molecule when scrutinized for pharmacophore and QSAR properties, like polar surface area, molar refractivity, oral bioavailability, solubility, transport across the gut, resistance to blood brain barrier and intestinal absorption, showed values mostly falling in prescribed range. It also highlighted that the inhibitor is non-toxic and non-carcinogenic property. Therefore, C 24 H 26 ClN 3 O 4 S can be used as a better and potent drug for treatment of diabetes Type 2 in comparison to glibenclamide. Graphic Abstract
International journal of biological macromolecules, Jan 3, 2018
β-Amylase from un-germinated seeds of peanut (Arachis hypogaea) was purified to apparent electrop... more β-Amylase from un-germinated seeds of peanut (Arachis hypogaea) was purified to apparent electrophoretic homogeneity with final purification fold of 205 and specific activity of 361μmol/min/mg protein. The enzyme was purified employing simple purification techniques for biochemical characterization. The purified enzyme was identified as β-amylase with Mof 31kDa. The enzyme displayed its optimum catalytic activity at pH5.0 and 60°C with activation energy of 4.5kcal/mol and Q1.2. The enzyme displayed Kand Vvalues, for soluble potato starch of 1.28mg/mL and 363.63μmol/min/mg, respectively. Thermal inactivation of β-amylase at 65°C resulted into first-order kinetics with rate constant 0.0126minand t55min. The enzyme was observed to act on native granular potato starch, which could minimize the high cost occurring from solubilization of starch in industries. Enzyme fractions scavenge 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical, indicating its antioxidative nature. In addition, the...
Highly fluorescent nitrogen doped carbon quantum dots (NCQDs) were synthesized using microwave as... more Highly fluorescent nitrogen doped carbon quantum dots (NCQDs) were synthesized using microwave assisted green method. It was characterized by Transmission Electron Microscopy (TEM), FTIR, UV-Visible absorption and Photoluminiscence (PL) techniques. The NCQDs were immobilized with an enzyme named quinolinate phoshphoribosyl transferase (QPRTase). The NCQDs immobilized by QPRTase was used as a fluorescent bioprobe for the selective detection of endogenous neurotoxin quinolinic acid (QA) whose elevated level in serum is marker of many neurological disorders such as Alzheimer's, Huntington's and HIV associated dementia (HAD) as well as deficiency of vitamin B6. Steady state PL studies were carried out to measure the PL response of the fabricated fluorescent bioprobe as a function of QA concentrations in human serum samples. This probe was found applicable in linear range [3.22-51µM] with the limit of detection ~ 6.51µM. It has desirable sensitivity ~ (0.02340±0.0001) µM-1, excel...
Jack bean urease was immobilized on gelatin beads with the help of glutaraldehyde. The optimum im... more Jack bean urease was immobilized on gelatin beads with the help of glutaraldehyde. The optimum immobilization (67.6%) was obtained at 30mg/ml gelatin concentration, 0.5 mg/bead enzyme protein concentration, 1 % glutaraldehyde and at incubation temperature. The of immobilized urease was approximately 90 days at compared with of 20 days for the soluble urease, under identical condition. The apparent optimum pH shifted from 7.3 to 8.0 when the urease was immobilized. The optimum stability temperature of immobilized urease was found to be while that of soluble urease was . Time-dependent thermal inactivation studies showed monophasic kinetics for soluble urease and immobilized urease at , respectively. The immobilized urease beads stored at showed practically no leaching over a period of 30 days. Here we are presenting an easy and economical way of immobilizing urease on the gelatin beads making it suitable for various applications.
Abstract Present study reports the utilization of molybdenum sulfide nanosheets (MoS 2 -NSs) as a... more Abstract Present study reports the utilization of molybdenum sulfide nanosheets (MoS 2 -NSs) as a novel platform for β -amylase immobilization via glutaraldehyde activation, producing nanobiocatalyst with exotic superiority over the independent enzyme. Confocal microscopy, Fourier transform infrared (FT-IR) spectroscopy, Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) studies demonstrated successful immobilization of β -amylase onto MoS 2 -NSs. Optimizing parameters by Box-Behnken design of Response Surface Methodology, approximately 92% immobilization efficiency was achieved. Thermo-stability, pH stability, reusability and storage stability of immobilized β -amylase were interestingly superior with respect to the soluble enzyme. β -Amylase immobilized onto MoS 2 -NSs exhibited maximum catalytic activity at the same pH and temperature as the soluble enzyme but with broadening in the range of parameters. In addition, the immobilized enzyme retained almost 80% residual activity, even after 10 reuses. Immobilized enzyme had around 83% residual activity upon storage over a period of 50 days. Changes in Michaelis-Menten constant after immobilization, point that some of the active sites of enzyme were inaccessible to substrate due to strained enzyme structure upon immobilization. The results obtained here suggest that the β -amylase-MoS 2 -NSs system could be used in industrial processes permitting broader temperature and pH ranges. Besides, the non-toxic nature of matrix, long-term storage and reusability of nanobiocatalyst could be magnificently used for the production of maltose in food and pharmaceutical industries.
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Papers by Arvind M. Kayastha