02266nas a2200241   4500008004100000022001400041245011000055210006900165260007300234300000800307490000700315520137800322653001601700653002001716653001801736653002501754653002501779100002901804700002601833700001901859700002001878856012601898       2015                        eng d  a0141-813000aPenicillin V acylase from pectobacterium atrosepticum exhibits high specific activity and unique kinetics0 aPenicillin V acylase from pectobacterium atrosepticum exhibits h  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a1-70 v793 a<p>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.</p>10aCooperative10aEnzyme kinetics10aGram-negative10aPenicillin V acylase10aSubstrate inhibition1 aAvinash, Vellore, Sunder1 aRamasamy, Sureshkumar1 aSuresh, C., G.1 aPundle, Archana  uhttps://library.ncl.res.in/content/penicillin-v-acylase-pectobacterium-atrosepticum-exhibits-high-specific-activity-and-002266nas a2200277   4500008004100000022001400041245007800055210006900133260009200202300001200294490000700306520130400313653001601617653002001633653001701653653001901670653001801689653001901707653001501726653001501741100002901756700002801785700002601813700003501839856011401874       2016                        eng d  a0738-855100aPenicillin acylases revisited: importance beyond their industrial utility0 aPenicillin acylases revisited importance beyond their industrial  a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcMAR  a303-3160 v363 a<p>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.</p>10abeta-lactam10acholoyl glycine10ain vivo role10aNtn hydrolases10apathogenicity10aquorum sensing10aregulation10asignalling1 aAvinash, Vellore, Sunder1 aPundle, Archana, Vishnu1 aRamasamy, Sureshkumar1 aSuresh, Cheravakkattu, Gopalan  uhttps://library.ncl.res.in/content/penicillin-acylases-revisited-importance-beyond-their-industrial-utility-0