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M. I. Oshtrakh A. L. Berkovsky A. Kumar S. Kundu A. V. Vinogradov T. S. Konstantinova V. A. Semionkin 《Biometals》2011,24(3):501-512
A comparative study of oxyhemoglobins from pig, rabbit, normal human and patients with blood system malignant diseases was performed using Mössbauer spectroscopy with a high velocity resolution at 90 K. Mössbauer spectra were fitted with the help of two models: using one quadrupole doublet (model of equivalent iron electronic structure in α- and β-subunits of hemoglobins) and superposition of two quadrupole doublets (model of non-equivalent iron electronic structure in α- and β-subunits of hemoglobins). The results obtained using both models demonstrated small variations of hyperfine parameters that were related to the heme iron state variation in different hemoglobins. These results were compared with structural and functional differences of the hemoglobins investigated. 相似文献
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Chatterjee P Basu S Kundu M Nasipuri M Plewczynski D 《Journal of molecular modeling》2011,17(9):2191-2201
Secondary structure prediction is a crucial task for understanding the variety of protein structures and performed biological
functions. Prediction of secondary structures for new proteins using their amino acid sequences is of fundamental importance
in bioinformatics. We propose a novel technique to predict protein secondary structures based on position-specific scoring
matrices (PSSMs) and physico-chemical properties of amino acids. It is a two stage approach involving multiclass support vector
machines (SVMs) as classifiers for three different structural conformations, viz., helix, sheet and coil. In the first stage, PSSMs obtained from PSI-BLAST and five specially selected physicochemical properties
of amino acids are fed into SVMs as features for sequence-to-structure prediction. Confidence values for forming helix, sheet and coil that are obtained from the first stage SVM are then used
in the second stage SVM for performing structure-to-structure prediction. The two-stage cascaded classifiers (PSP_MCSVM) are trained with proteins from RS126 dataset. The classifiers
are finally tested on target proteins of critical assessment of protein structure prediction experiment-9 (CASP9). PSP_MCSVM
with brainstorming consensus procedure performs better than the prediction servers like Predator, DSC, SIMPA96, for randomly
selected proteins from CASP9 targets. The overall performance is found to be comparable with the current state-of-the art. PSP_MCSVM source code, train-test datasets and supplementary files are available freely in public domain at: and 相似文献
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Sayantari Ghosh Kamakshi Sureka Bhaswar Ghosh Indrani Bose Joyoti Basu Manikuntala Kundu 《BMC systems biology》2011,5(1):18
Background
A common survival strategy of microorganisms subjected to stress involves the generation of phenotypic heterogeneity in the isogenic microbial population enabling a subset of the population to survive under stress. In a recent study, a mycobacterial population of M. smegmatis was shown to develop phenotypic heterogeneity under nutrient depletion. The observed heterogeneity is in the form of a bimodal distribution of the expression levels of the Green Fluorescent Protein (GFP) as reporter with the gfp fused to the promoter of the rel gene. The stringent response pathway is initiated in the subpopulation with high rel activity. 相似文献57.
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Punita?Mishra Pradeep?SrivastavaEmail author Subir?Kundu 《World journal of microbiology & biotechnology》2005,21(4):525-530
The production of Cephalosporin-C (CPC) a secondary metabolite, using a mold Acremonium chrysogenum was studied in a lab scale Internal loop air lift reactor. Cephalosporin-C production process is a highly aerobic fermentation process. Volumetric gas–liquid mass transfer coefficient (kLa) and viscosity (η) were evaluated, during the growth and production phases of the microbial physiology. An attempt has been made to correlate the broth viscosity, η and volumetric oxygen transfer coefficient, kLa during the Cephalosporin-C production in an air lift reactor. The impact of biomass concentration and mycelial morphology on broth viscosity has been also evaluated. The broth exhibits a typical non-Newtonian fermentation broth. Rheology parameters like consistency index and fluidity index are also studied. 相似文献