<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kumar, R. Suresh</style></author><author><style face="normal" font="default" size="100%">Brannigan, James A.</style></author><author><style face="normal" font="default" size="100%">Prabhune, Asmita</style></author><author><style face="normal" font="default" size="100%">Pundle, Archana V.</style></author><author><style face="normal" font="default" size="100%">Dodson, Guy G.</style></author><author><style face="normal" font="default" size="100%">Dodson, Eleanor J.</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structural and functional analysis of a conjugated bile salt hydrolase from Bifidobacterium longum reveals an evolutionary relationship with penicillin V acylase</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Biological Chemistry</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">OCT</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">43</style></number><publisher><style face="normal" font="default" size="100%">AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC</style></publisher><pub-location><style face="normal" font="default" size="100%">9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA</style></pub-location><volume><style face="normal" font="default" size="100%">281</style></volume><pages><style face="normal" font="default" size="100%">32516-32525</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Bile salt hydrolase (BSH) is an enzyme produced by the intestinal microflora that catalyzes the deconjugation of glycine- or taurine-linked bile salts. The crystal structure of BSH reported here from Bifidobacterium longum reveals that it is a member of N-terminal nucleophil hydrolase structural superfamily possessing the characteristic alpha beta beta alpha tetra-lamellar tertiary structure arrangement. Site-directed mutagenesis of the catalytic nucleophil residue, however, shows that it has no role in zymogen processing into its corresponding active form. Substrate specificity was studied using Michaelis-Menten and inhibition kinetics and fluorescence spectroscopy. These data were compared with the specificity profile of BSH from Clostridium perfrigens and pencillin V acylase from Bacillus sphaericus, for both of which the three-dimensional structures are available. Comparative analysis shows a gradation in activity toward common substrates, throwing light on a possible common route toward the evolution of pencillin V acylase and BSH.&lt;/p&gt;</style></abstract><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">4.258</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kumar, R. Suresh</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author><author><style face="normal" font="default" size="100%">Brannigan, James A.</style></author><author><style face="normal" font="default" size="100%">Dodson, Guy G.</style></author><author><style face="normal" font="default" size="100%">Gaikwad, Sushama M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Bile salt hydrolase, the member of Ntn-hydrolase family: differential modes of structural and functional transitions during denaturation</style></title><secondary-title><style face="normal" font="default" size="100%">IUBMB Life</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Aggregation</style></keyword><keyword><style  face="normal" font="default" size="100%">Bile salt hydrolase</style></keyword><keyword><style  face="normal" font="default" size="100%">molten-globule</style></keyword><keyword><style  face="normal" font="default" size="100%">Unfolding</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">FEB</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">2</style></number><publisher><style face="normal" font="default" size="100%">TAYLOR &amp; FRANCIS INC</style></publisher><pub-location><style face="normal" font="default" size="100%">325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA</style></pub-location><volume><style face="normal" font="default" size="100%">59</style></volume><pages><style face="normal" font="default" size="100%">118-125</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Conformational transitions and functional stability of the bile salt hydrolase (BSH; cholylglycine EC: 3.5.1.24) from Bifidobacterium longum (BlBSH) cloned and expressed in E. coli were studied under thermal, chemical and pH-mediated denaturation conditions using fluorescence and CD spectroscopy. Thermal and Gdn-HCl-mediated denaturation of BlBSH is a multistep process of inactivation and unfolding. The inactivation and unfolding of the enzyme was found to be irreversible. Enzyme activity seems sensitive to even minor conformational changes at the active site. Thermal denaturation as such did not result in any insoluble protein aggregates. However, on treating with 0.25-1 M Gdn-HCl the enzyme showed increasing aggregation at temperatures of 40-55 degrees C indicating more complex structural changes taking place in the presence of chemical denaturants. The enzyme secondary structure was still intact at acidic pH (pH 1-3). The perturbation in the tertiary structure at the acidic pH was detected through freshly formed solvent exposed hydrophobic patches on the enzyme. These changes could be due to the formation of an acid-induced molten globule-like state.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">2.653</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kumar, R. Suresh</style></author><author><style face="normal" font="default" size="100%">Prabhune, Asmita</style></author><author><style face="normal" font="default" size="100%">Pundle, A. V.</style></author><author><style face="normal" font="default" size="100%">Karthikeyan, Muthukumarasamy</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Tryptophan residue is identified in the substrate binding of penicillin G acylase from Kluyvera citrophila</style></title><secondary-title><style face="normal" font="default" size="100%">Enzyme and Microbial Technology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">fluorescence measurement</style></keyword><keyword><style  face="normal" font="default" size="100%">K. citrophila</style></keyword><keyword><style  face="normal" font="default" size="100%">Penicillin G acylase</style></keyword><keyword><style  face="normal" font="default" size="100%">sequence alignment</style></keyword><keyword><style  face="normal" font="default" size="100%">substrate-docking</style></keyword><keyword><style  face="normal" font="default" size="100%">tryptophan modification</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">APR</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">5</style></number><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE INC</style></publisher><pub-location><style face="normal" font="default" size="100%">360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA</style></pub-location><volume><style face="normal" font="default" size="100%">40</style></volume><pages><style face="normal" font="default" size="100%">1389-1397</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Penicillin acylases are important enzymes in pharmaceutical industry for the production of semi-synthetic beta-lactam antibiotics via the key intermediate 6-aminopenicillanic acid. The penicillin G acylase purified from Kluyvera citrophila (KcPGA) on modification with tryptophan-specific reagents such as N-bromo succinamide (NBS) and 2-hydroxy 5-nitrobenzylbromide (HNBB) showed partial loss of activity and substrate protection. Various solute quenchers and substrate were used to probe the microenvironment of the putative reactive tryptophan through fluorescence quenching. Homology modeling of KcPGA structure has been carried out. Docking substrate on this modeled KcPGA structure identifies the tryptophan residue that is directly influenced by substrate binding. To confirm the biological significance of this particular tryptophan, we did a sequence comparison of PGAs from various organisms. The sequence alignment clustered the matches into two sets, those closer to (&amp;gt; 40% identical) KcPGA and had the tryptophan of interest present in them formed the first set, while those less identical (&amp;lt; 30%) to KcPGA and the particular tryptophan absent in them formed the second set. It is clear from the reported kinetic parameters of representative members of these two sets that the affinity for penicillin G (penG) of the former class is several times better. Thus, based on our studies we suggest that the tryptophan residue in the identified position is important for binding substrate penG by the acylases. (c) 2006 Elsevier Inc. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">2.624</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Varshney, Nishant Kumar</style></author><author><style face="normal" font="default" size="100%">Kumar, R. Suresh</style></author><author><style face="normal" font="default" size="100%">Ignatova, Zoya</style></author><author><style face="normal" font="default" size="100%">Prabhune, Asmita</style></author><author><style face="normal" font="default" size="100%">Pundle, Archana</style></author><author><style face="normal" font="default" size="100%">Dodson, Eleanor J.</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Crystallization and X-ray structure analysis of a thermostable penicillin G acylase from alcaligenes faecalis</style></title><secondary-title><style face="normal" font="default" size="100%">Acta Crystallographica Section F-Structural Biology and Crystallization Communications</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">calcium binding</style></keyword><keyword><style  face="normal" font="default" size="100%">disulfide bridges</style></keyword><keyword><style  face="normal" font="default" size="100%">Ntn hydrolases</style></keyword><keyword><style  face="normal" font="default" size="100%">orthorhombic form</style></keyword><keyword><style  face="normal" font="default" size="100%">tetragonal form</style></keyword><keyword><style  face="normal" font="default" size="100%">Thermostability</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAR</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">3</style></number><publisher><style face="normal" font="default" size="100%">WILEY-BLACKWELL</style></publisher><pub-location><style face="normal" font="default" size="100%">COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA</style></pub-location><volume><style face="normal" font="default" size="100%">68</style></volume><pages><style face="normal" font="default" size="100%">273-277</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;{The enzyme penicillin G acylase (EC 3.5.1.11) catalyzes amide-bond cleavage in benzylpenicillin (penicillin G) to yield 6-aminopenicillanic acid, an intermediate chemical used in the production of semisynthetic penicillins. A thermostable penicillin G acylase from Alcaligenes faecalis (AfPGA) has been crystallized using the hanging-drop vapour-diffusion method in two different space groups: C2221, with unit-cell parameters a = 72.9&lt;/p&gt;</style></abstract><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">0.552
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