<?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%">Avinash, Vellore Sunder</style></author><author><style face="normal" font="default" size="100%">Ramasamy, Sureshkumar</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author><author><style face="normal" font="default" size="100%">Pundle, Archana</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Penicillin V acylase from pectobacterium atrosepticum exhibits high specific activity and unique kinetics</style></title><secondary-title><style face="normal" font="default" size="100%">International Journal of Biological Macromolecules</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cooperative</style></keyword><keyword><style  face="normal" font="default" size="100%">Enzyme kinetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Gram-negative</style></keyword><keyword><style  face="normal" font="default" size="100%">Penicillin V acylase</style></keyword><keyword><style  face="normal" font="default" size="100%">Substrate inhibition</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">AUG</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">79</style></volume><pages><style face="normal" font="default" size="100%">1-7</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 V acylases (PVAs, E.C.3.5.11) belong to the Ntn hydrolase super family of enzymes that catalyze the deacylation of the side chain from phenoxymethyl penicillin (penicillin V). Penicillin acylases find use in the pharmaceutical industry for the production of semi-synthetic antibiotics. PVAs employ the N-terminal cysteine residue as catalytic nucleophile and are structurally and evolutionarily related to bile salt hydrolases (BSHs). Here, we report the cloning and characterization of a PVA enzyme from the Gram-negative plant pathogen, Pectobacterium atrosepticum (PaPVA). The enzyme was cloned and expressed in Escherichia coli attaining a very high yield (250 mg/l) and a comparatively high specific activity (430 IU/mg). The enzyme showed marginally better pH and thermo-stability over PVAs characterized from Gram-positive bacteria. The enzyme also showed enhanced activity in presence of organic solvents and detergents. The enzyme kinetics turned out to be significantly different from that of previously reported PVAs, displaying positive cooperativity and substrate inhibition. The presence of bile salts had a modulating effect on PaPVA activity. Sequence analysis and characterization reveal the distinctive nature of these enzymes and underscore the need to study PVAs from Gram-negative bacteria. (C) 2015 Elsevier B.V. All rights reserved.&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%">3.138</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%">Avinash, Vellore Sunder</style></author><author><style face="normal" font="default" size="100%">Pundle, Archana Vishnu</style></author><author><style face="normal" font="default" size="100%">Ramasamy, Sureshkumar</style></author><author><style face="normal" font="default" size="100%">Suresh, Cheravakkattu Gopalan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Penicillin acylases revisited: importance beyond their industrial utility</style></title><secondary-title><style face="normal" font="default" size="100%">Critical Reviews In Biotechnology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">beta-lactam</style></keyword><keyword><style  face="normal" font="default" size="100%">choloyl glycine</style></keyword><keyword><style  face="normal" font="default" size="100%">in vivo role</style></keyword><keyword><style  face="normal" font="default" size="100%">Ntn hydrolases</style></keyword><keyword><style  face="normal" font="default" size="100%">pathogenicity</style></keyword><keyword><style  face="normal" font="default" size="100%">quorum sensing</style></keyword><keyword><style  face="normal" font="default" size="100%">regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">signalling</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2016</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%">2</style></number><publisher><style face="normal" font="default" size="100%">TAYLOR &amp; FRANCIS LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND</style></pub-location><volume><style face="normal" font="default" size="100%">36</style></volume><pages><style face="normal" font="default" size="100%">303-316</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;It is of great importance to study the physiological roles of enzymes in nature; however, in some cases, it is not easily apparent. Penicillin acylases are pharmaceutically important enzymes that cleave the acyl side chains of penicillins, thus paving the way for production of newer semi-synthetic antibiotics. They are classified according to the type of penicillin (G or V) that they preferentially hydrolyze. Penicillin acylases are also used in the resolution of racemic mixtures and peptide synthesis. However, it is rather unfortunate that the focus on the use of penicillin acylases for industrial applications has stolen the spotlight from the study of the importance of these enzymes in natural metabolism. The penicillin acylases, so far characterized from different organisms, show differences in their structural nature and substrate spectrum. These enzymes are also closely related to the bacterial signalling phenomenon, quorum sensing, as detailed in this review. This review details studies on biochemical and structural characteristics of recently discovered penicillin acylases. We also attempt to organize the available insights into the possible in vivo role of penicillin acylases and related enzymes and emphasize the need to refocus research efforts in this direction.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><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%">7.51</style></custom4></record></records></xml>