Showing papers on "Penicillin amidase published in 1988"
TL;DR: Results and electrophoretic and spectroscopic analysis indicated that the denaturation was caused by partial unfolding during the depressurization step.
Abstract: The stability of the monomeric enzymes α-chymotrypsin and trypsin, and the oligomeric enzyme penicillin amidase in supercritical CO2 has been studied. They were found to be partly denatured during the depressurization step. The degree of denaturation was larger in humid CO2 than in dry CO2. Enzymes with S-S bridges (α-chymotrypsin; trypsin) were denatured to a lesser degree than the enzyme without cysteine (penicillin amidase). These results and electrophoretic and spectroscopic analysis indicated that the denaturation was caused by partial unfolding during the depressurization step.
80 citations
TL;DR: Penicillin acylase from E. coli (EC 3.11) accepts a broad range of N-phenylacetyl-dipeptide esters as substrates and hydrolyses the N-terminal protecting group selectively at room temp.
46 citations
TL;DR: Penicillin G acylase was purified from the cultured filtrate of Arthrobacter viscosus 8895GU and was found to consist of two distinct subunits with apparent molecular weights of 24,000 and 60,000.
Abstract: Penicillin G acylase was purified from the cultured filtrate of Arthrobacter viscosus 8895GU and was found to consist of two distinct subunits with apparent molecular weights of 24,000 (alpha) and 60,000 (beta). The partial N-terminal amino acid sequences of the alpha and beta subunits were determined with a protein gas phase sequencer, and a 29-base oligonucleotide corresponding to the partial amino acid sequence of the alpha subunit was synthesized. An Escherichia coli transformant having the penicillin G acylase gene was isolated from an A. viscosus gene library by hybridization with the 29-base probe. The resulting positive clone was further screened by the Serratia marcescens overlay technique. E. coli carrying a plasmid designated pHYM-1 was found to produce penicillin G acylase in the cells. This plasmid had an 8.0-kilobase pair DNA fragment inserted in the EcoRI site of pACYC184.
45 citations
TL;DR: Penicillinacylase from Ecoli, immoblized on Eupergit C beads catalyzes the hydrolysis in water/CH 3 CN 10:1, at pH 75 and 23° C, of a set of O-phenylacetate esters of primary carbinols as discussed by the authors.
34 citations
TL;DR: The near-UV and far-UV CD spectrum in the presence of penicillin G sulfoxide showed that the binding of this inhibitor to the enzyme resulted in modification of the dichroism of several aromatic residues.
Abstract: The mature penicillin G acylase fromKluyvera citrophila was examined by circular dichroism (CD). The far-UV CD spectrum at neutral pH revealed 11% alpha-helix, 44% beta-sheet, 11% beta-turn and 34% random coil. Far-UV and near-UV CD spectra showed that the enzyme presented a high conformational stability under different conditions of pH and salt concentration. The predictive model of Chou and Fasman indicated the presence of several beta-segments that could be arranged in antiparallel beta-sheets, which might explain the structural stability. The near-UV CD spectrum in the presence of penicillin G sulfoxide showed that the binding of this inhibitor to the enzyme resulted in modification of the dichroism of several aromatic residues.
7 citations