Peculiar Stability of Amino Acids and Peptides from a Radical Perspective
作者:Zachary I. Watts、Christopher J. Easton
DOI:10.1021/ja9027583
日期:2009.8.19
Photochemical reactions of free and N-acetyl alpha-amino acids with chlorine and deuterium labeled hydrogen peroxide have been used to determine both the relative rates of reaction of molecules of these classes and the relative reactivity of their different types of hydrogen toward abstraction by chlorine and oxygen centered radicals. The relative rates of reaction of these species range over more than 3 orders
Penicillin biosynthesis: direct biosynthetic formation of penicillin V and penicillin G
作者:Jack E. Baldwin、Edward P. Abraham、Geoffrey L. Burge、Hong-Hoi Ting
DOI:10.1039/c39850001808
日期:——
The enzyme isopenicillin N synthetase is able to convert directly the dipeptides, phenoxyacetylcysteinylvaline and phenylacetylcysteinylvaline into penicillin V and G respectively; these are however very slow compared with substrates of the α-aminoadipoyl or adipoylcysteinylvaline type.
The crystal structure of isopenicillin N synthase with δ-(l-α-aminoadipoyl)-l-cysteinyl-d-methionine reveals thioether coordination to iron
作者:Ian J. Clifton、Wei Ge、Robert M. Adlington、Jack E. Baldwin、Peter J. Rutledge
DOI:10.1016/j.abb.2011.09.014
日期:2011.12
IsopenicillinNsynthase (IPNS) catalyses cyclization of δ-(l-α-aminoadipoyl)-l-cysteinyl-d-valine (ACV) to isopenicillinN (IPN), the central step in penicillin biosynthesis. Previous studies have shown that IPNS turns over a wide range of substrate analogues in which the valine residue of its natural substrate is replaced with other amino acids. IPNS accepts and oxidizes numerous substrates that
Conversion of<sup>17</sup>O/<sup>18</sup>O-labelled δ-(<scp>L</scp>-α-aminoadipyl)–<scp>L</scp>-cycteinyl–<scp>D</scp>-valine into<sup>17</sup>O/<sup>18</sup>O-labelled isopenicillin N in a cell-free extract of C. acremonium
作者:Robert M. Adlington、Robin T. Aplin、Jack E. Baldwin、Leslie D. Field、Eeva-M. M. John、Edward P. Abraham、Robert L. White
DOI:10.1039/c39820000137
日期:——
δ-(L-α-Amino[1,1,6-17O/18O]-adipyl)-L-cysteiny-D-valine was converted into isopenicillin N in cell-free extracts of Cephalosporium acremonium with no loss of 17O/18O label as shown by 17O n.m.r. spectroscopy and mass spectrometry; incubation of unlabelled tripeptide in cell-free system containing 17O/18O-enriched water produced isopenicillin N with no incorporation of 17O/18O.
Direct n.m.r. observation of cell-free conversion of (<scp>L</scp>-α-amino-δ-adipyl)-<scp>L</scp>-cysteinyl-<scp>D</scp>-valine into isopenicillin N
作者:Jack E. Baldwin、Brian L. Johnson、John J. Usher、Edward P. Abraham、Joyce A. Huddleston、Robert L. White
DOI:10.1039/c39800001271
日期:——
Carbon-13 n.m.r. spectroscopy has been used to observe the efficient conversion of (L-α-amino-δ-adipyl)-L-cysteinyl-D-valine into isopenicillin N in cell-free extracts of Cephalosporium acremonium.
碳-13 n.m.r.光谱被用来观察头孢痤疮菌无细胞提取物中 (L-δ-amino-δ-´-adipyl)-L-cysteinyl-D-valine 向异青霉素 N 的高效转化。