@article { ISI:000237610600013, title = {Purification, characterization and substrate specificity of thermostable alpha-galactosidase from Bacillus stearothermophilus (NCIM-5146)}, journal = {Process Biochemistry}, volume = {41}, number = {6}, year = {2006}, month = {JUN}, pages = {1311-1317}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

An extracellular thermostable alpha-galactosidase from Bacillus stearothermophilus (NCIM-5146) has been purified to homogeneity by chromatographic step, using Phenyl Sepharose CL-4B column. The specific activity of the enzyme was increased approximately 389-fold, from 1.03 U/mg protein to 400 U/mg protein. The molecular mass of the purified enzyme as determined by SDS-PAGE and gel filtration was 79.9 and 165.9 kDa, respectively, suggesting dimeric nature. The purified alpha-galactosidase is a non-glycosylated protein with a pI of 4.9. The pH and temperature optima for the purified enzyme are 6.5-7.0 and 65 degrees C, respectively. The alpha-galactosidase is stable over a broad pH range (3-9) and its half-life of inactivation (t(1/2)) at 70 degrees C is 30 min. The partial N-terminal sequence of alpha-galactosidase showed remarkable homology (80\% similarity) with earlier reported alpha-galactosidase from B. stearothermophilus NUB 3621. The secondary structure of the enzyme determined by circular dichroism (CD) spectroscopy exhibited alpha/beta class of protein and showed temperature induced conformational forms below and above the transition temperature. The purified enzyme showed biphasic Arrhenius plot with break point at 55 degrees C for pNPG and 50 degrees C for melibiose, raffinose and stachyose. The enzyme hydrolyzes alpha-1-3, alpha-1-4, and alpha-1-6 galactosidic linkages and not the beta-galactosidic linkages. Synthetic substrates pNPG and oNPG had lower K-m and higher K-cat as compare to natural substrates, melibiose, raffinose, and stachyose. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {alpha-galactosidase, Bacillus stearothermophilus (NCIM-5146), Purification, Secondary structure, thermostable enzyme}, issn = {1359-5113}, doi = {10.1016/j.procbio.2006.01.003}, author = {Gote, M. M. and Khan, Mohammad Islam and Gokhale, D. V. and Bastawade, Kulbhushan B. and Khire, Jayant Malhar} } @article { ISI:000243572800014, title = {Purification and characterization of a lectin from endophytic fungus fusarium solani having complex sugar specificity}, journal = {Archives of Biochemistry and Biophysics }, volume = {457}, number = {2}, year = {2007}, month = {JAN}, pages = {243-251}, publisher = {ELSEVIER SCIENCE INC}, type = {Article}, address = {360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA}, abstract = {

A lectin from the mycelial extract of an endophytic strain of Fusarium solani was purified. Its hemagglutinating activity was inhibited by glycoproteins possessing N-linked as well as O-linked glycans. The thermodynamics and kinetics of binding of glycans and glycoproteins to F. solani lectin Was Studied using SUH ace plasmon resonance. The lectin showed high affinity for asialofetuin, asia-lofibrinogen, asialofibrinogen, and thyroglobulin: and comparatively low affinity for mucin, fetuin, fibrinogen, and holotransferrin. Glycoproteins showed glycans with significant contribution from enthalpy and positive entropy, suggesting several fold higher affinity than their corresponding g the involvement of non-polar protein-protein interaction. Moreover, the higher affinity of the glycoproteins was due to their faster association rates and low activation energy. (c) 2006 Elsevier Inc. All rights reserved.

}, keywords = {endophytic fungus, Fusarium solani, Lectin, Purification, SPR, Thermodynamic properties}, issn = {0003-9861}, doi = {10.1016/j.abb.2006.10.019}, author = {Khan, Feroz and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000254697200009, title = {Purification and characterization of a T-antigen specific lectin from the coelomic fluid of a marine invertebrate, sea cucumber (Holothuria scabra)}, journal = {Fish \& Shellfish Immunology}, volume = {24}, number = {4}, year = {2008}, month = {APR}, pages = {450-458}, publisher = {ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD}, address = {24-28 OVAL RD, LONDON NW1 7DX, ENGLAND}, abstract = {

A novel lectin was purified from the coelomic fluid of the sea cucumber Holothuria scabra (HSL), subjected to bacterial challenge. HSL is a monomeric glycoprotein of molecular mass 182 kDa. The lectin is highly thermostable as it retains full activity for 1 h at 80 degrees C. Further, the hemagglutination activity of HSL is unaffected by pH in the range 2-11. Unlike other lectins purified from marine invertebrates, the hemagglutination activity of HSL does not require any divalent metal ions. The affinity profile of HSL was studied by a combination of hemagglutination inhibition and fluorescence spectroscopy. HSL binds to desialylated glycoproteins, Me alpha Gal, T-antigen and T (alpha-ser)-antigen with a distinction between beta 1-4 and beta 1-3 linkages. Me alpha-T-antigen was a potent ligand having highest affinity (K-a 8.32 x 10(7) M-1). Monosaccharide binding is enthalphically driven while disaccharide binding involves both entropic and enthalpic contributions. (c) 2008 Elsevier Ltd. All rights reserved.

}, keywords = {Fluorescence spectroscopy, Holothuria scabra, Lectin, marine invertebrate, Thermodynamic properties}, issn = {1050-4648}, doi = {10.1016/j.fsi.2008.01.002}, author = {Gowda, Nagaraj M. and Goswami, Usha and Khan, Mohammad Islam} } @article { ISI:000272302200009, title = {Production, purification, and characterization of taxol and 10-DABIII from a new endophytic fungus gliocladium sp isolated from the Indian yew tree, taxus baccata}, journal = {Journal of Microbiology and Biotechnology}, volume = {19}, number = {11}, year = {2009}, month = {NOV}, pages = {1342-1347}, publisher = {KOREAN SOC MICROBIOLOGY \& BIOTECHNOLOGY}, address = {KOREA SCI TECHNOL CENTER \#507, 635-4 YEOGSAM-DONG, KANGNAM-GU, SEOUL 135-703, SOUTH KOREA}, abstract = {

We have isolated endophytic fungi from the Indian yew tree, Taxus baccata, and then screened for taxol production. Out of the 40 fungal cultures screened, one fungus Gliocladium sp. was found to produce taxol and 10-DABIII (10-deacetyl baccatin III). These compounds were purified by TLC and HPLC and characterized using UV-spectroscopy, ESI-MS, MS/MS, and proton NMR. One liter of Gliocladium sp. culture yielded 10 mu g of taxol and 65 mu g of 10-DABIII. The purified taxol from the fungus showed cytotoxicity towards cancer lines HL-60 (leukemia), A431 (epidermal carcinoma), and MCF-7 (breast cancer).

}, keywords = {10 DAB III, Endophytic fungi, Gliocladium sp., Taxol, Taxus baccata}, issn = {1017-7825}, doi = {10.4014/jmb.0904.04041}, author = {Sreekanth, D. and Syed, A. and Sarkar, S. and Sarkar, Dhiman and Santhakumari, B. and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000265921000002, title = {Purification and characterization of putative alkaline [Ni-Fe] hydrogenase from unicellular marine green alga, tetraselmis kochinensis NCIM 1605}, journal = {Microbiological Research}, volume = {164}, number = {2}, year = {2009}, month = {FEB}, pages = {131-137}, publisher = {ELSEVIER GMBH, URBAN \& FISCHER VERLAG}, address = {OFFICE JENA, P O BOX 100537, 07705 JENA, GERMANY}, abstract = {

Hydrogenase enzyme from the unicellular marine green alga Tetraselmis kochinensis NCIM 1605 was purified 467 fold to homogeneity. The molecular weight was estimated to be similar to 89kDa by SDS-PAGE. This enzyme consists of two subunits with molecular masses of similar to 70 and similar to 19 kDa. The hydrogenase was found to contain 10 g atoms of Fe and 1 g of atom of Ni per mote of protein. The specific activity of hydrogen evolution was 50 mu mol H-2/mg/h of enzyme using reduced methyl viologen as an electron donor. This hydrogenase enzyme has pl value similar to 9.6 representing its alkaline nature. The absorption spectrum of the hydrogenase enzyme showed an absorption peak at 425 nm indicating that the enzyme had iron-sulfur clusters. The total of 16 cysteine residues were found per mote of enzyme under the denaturing condition and 20 cysteine residues in reduced denatured enzyme indicating that it has two disulfide bridges. (C) 2007 Published by Elsevier GmbH.

}, keywords = {Characterization, Chemical modification, Ni-Fe hydrogenase, Tetraselmis kochinensis, Unicellular green algae}, issn = {0944-5013}, doi = {10.1016/j.micres.2006.11.006}, author = {Bhosale, Siddharth H. and Pant, A. and Khan, Mohammad Islam} }