02185nas a2200265   4500008004100000022001400041245009100055210006900146260007300215300001000288490000700298520124000305653002201545653003601567653001801603653002301621100002401644700002501668700001901693700002101712700002501733700002001758700002401778856011701802       2012                        eng d  a0141-813000aPurification and characterization of YxeI, a penicillin acylase from Bacillus subtilis0 aPurification and characterization of YxeI a penicillin acylase f  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a25-300 v503 a<p>The paper reports the purification and characterization of the first penicillin acylase from Bacillus subtilis. YxeI, the protein annotated as hypothetical, coded by the gene yxeI in the open reading frame between iol and hut operons in B. subtilis was cloned and expressed in Eshcherichia coli, purified and characterized. The purified protein showed measurable penicillin acylase activity with penicillin V. The enzyme was a homotetramer of 148 kDa. The apparent Km of the enzyme for penicillin V and the synthetic substrate 2-nitro-5-(phenoxyacetamido)-benzoic acid was 40 mM and 0.63 mM, respectively, and the association constants were 8.93 x 10(2) M-1 and 2.51 x 10(5) M-1, respectively. It was inhibited by cephalosporins and conjugated bile salts, substrates of the closely related bile acid hydrolases. It had good sequence homology with other penicillin V acylases and conjugated bile acid hydrolases, members of the Ntn hydrolase family. The N-terminal nucleophile was a cysteine which is revealed by a simple removal of N-formyl-methionine. The activity of the protein was affected by high temperature, acidic pH and the presence of the denaturant guanidine hydrochloride. (C) 2011 Elsevier B.V. All rights reserved.</p>10aBacillus subtilis10aConjugated bile acid hydrolases10aNtn hydrolase10aPenicillin acylase1 aRathinaswamy, Priya1 aGaikwad, Sushama, M.1 aSuresh, C., G.1 aPrabhune, Asmita1 aBrannigan, James, A.1 aDodson, Guy, G.1 aPundle, Archana, V.  uhttps://library.ncl.res.in/content/purification-and-characterization-yxei-penicillin-acylase-bacillus-subtilis-001922nas a2200265   4500008004100000022001400041245011800055210006900173260009500242300001200337490000800349520092800357653002401285653001201309653002301321653001501344653001901359653002301378100002901401700002601430700001901456700002401475700002601499856013101525       2013                        eng d  a0006-291X00aStructural modelling of substrate binding and inhibition in penicillin V acylase from pectobacterium atrosepticum0 aStructural modelling of substrate binding and inhibition in peni  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcAUG  a538-5430 v4373 a<p>Penicillin V acylases (PVAs) and bile salt hydrolases (BSHs) have considerable sequence and structural similarity; however, they vary significantly in their substrate specificity. We have identified a PVA from a Gram-negative organism, Pectobacterium atrosepticum (PaPVA) that turned out to be a remote homolog of the PVAs and BSHs reported earlier. Even though the active site residues were conserved in PaPVA it showed high specificity towards penV and interestingly the penV acylase activity was inhibited by bile salts. Comparative modelling and docking studies were carried out to understand the structural differences of the binding site that confer this characteristic property. We show that PaPVA exhibits significant differences in structure, which are in contrast to those of known PVAs and such enzymes from Gram-negative bacteria require further investigation. (C) 2013 Elsevier Inc. All rights reserved.</p>10aBile salt hydrolase10adocking10aHomology modelling10aInhibition10aPectobacterium10aPenicillin acylase1 aAvinash, Vellore, Sunder1 aPanigrahi, Priyabrata1 aSuresh, C., G.1 aPundle, Archana, V.1 aRamasamy, Sureshkumar  uhttps://library.ncl.res.in/content/structural-modelling-substrate-binding-and-inhibition-penicillin-v-acylase-pectobacterium-002736nas a2200277   4500008004100000022001400041245013100055210006900186260008000255300001400335490000700349520172600356653001702082653002802099653002302127653002102150653001402171653002302185653002002208100002602228700001802254700002202272700002602294700001902320856011902339       2015                        eng d  a1367-543500aSequence and structure-based comparative analysis to assess, identify and improve the thermostability of penicillin G acylases0 aSequence and structurebased comparative analysis to assess ident  aTIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANYbSPRINGER HEIDELBERGcNOV  a1493-15060 v423 a<p>Penicillin acylases are enzymes employed by the pharmaceutical industry for the manufacture of semi-synthetic penicillins. There is a continuous demand for thermostable and alkalophilic enzymes in such applications. We have carried out a computational analysis of known penicillin G acylases (PGAs) in terms of their thermostable nature using various protein-stabilizing factors. While the presence of disulfide bridges was considered initially to screen putative thermostable PGAs from the database, various other factors such as high arginine to lysine ratio, less content of thermolabile amino acids, presence of proline in beta-turns, more number of ion-pair and other non-bonded interactions were also considered for comparison. A modified consensus approach designed could further identify stabilizing residue positions by site-specific comparison between mesostable and thermostable PGAs. A most likely thermostable enzyme identified from the analysis was PGA from Paracoccus denitrificans (PdPGA). This was cloned, expressed and tested for its thermostable nature using biochemical and biophysical experiments. The consensus site-specific sequence-based approach predicted PdPGA to be more thermostable than Escherichia coli PGA, but not as thermostable as the PGA from Achromobacter xylosoxidans. Experimental data showed that PdPGA was comparatively less thermostable than Achromobacter xylosoxidans PGA, although thermostability factors favored a much higher stability. Despite being mesostable, PdPGA being active and stable at alkaline pH is an advantage. Finally, several residue positions could be identified in PdPGA, which upon mutation selectively could improve the thermostability of the enzyme.</p>10aAlkalistable10abeta-lactam antibiotics10aConsensus approach10aDisulfide bridge10aIon pairs10aPenicillin acylase10aThermostability1 aPanigrahi, Priyabrata1 aChand, Deepak1 aMukherji, Ruchira1 aRamasamy, Sureshkumar1 aSuresh, C., G.  uhttps://library.ncl.res.in/content/sequence-and-structure-based-comparative-analysis-assess-identify-and-improve-0