Acylase I-Catalyzed Deacetylation of N-Acetyl-l-cysteine and S-Alkyl-N-acetyl-l-cysteines
摘要:
The aminoacylase that catalyzes the hydrolysis of N-acetyl-L-cysteine (NAC) was identified as acylase I after purification by column chromatography and electrophoretic analysis. Rat kidney cytosol was fractionated by ammonium sulfate precipitation, and the proteins were separated by ion-exchange column chromatography, gel-filtration column chromatography, and hydrophobic interaction column chromatography. Acylase activity with NAC and N-acetyl-L-methionine (NAM), a known substrate for acylase I, as substrates coeluted during all chromatographic steps. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the protein was purified to near homogeneity and had a subunit M-r of 43 000, which is identical with the M-r of acylase I from porcine kidney and bovine liver. n-Butylmalonic acid was a slow-binding inhibitor of acylase I and inhibited the deacetylation of NAC with a K-i of 192 +/- 27 mu M These results show that acylase I catalyzes the deacetylation of NAG. The acylase I-catalyzed deacetylation of a range of S-alkyl-N-acetyl-L-cysteines, their carbon and oxygen analogues, and the selenium analogue of NAM was also studied with porcine kidney acylase I. The specific activity of the acylase I-catalyzed deacetylation of these substrates was related to their calculated molar volumes and lag P values. The S-alkyl-N-acetyl-L-cysteines with short (C-0-C-3) and unbranched S-alkyl substituents were good acylase I substrates, whereas the S-alkyl-N-acetyl-L-cysteines with long (>C-3) and branched S-alkyl substituents were poor acylase I substrates. The carbon and oxygen analogues of S-methyl-N-acetyl-L-cysteine and the carbon analogue of S-ethyl-N-acetyl-L-cysteine were poor acylase I substrates, whereas the selenium analogue of NAM was a good acylase I substrate.
The synthesis of S-alkylated cysteinederivatives was carried out successfully in the presence of 1,1,3,3-tetramethylguanidine. Alkylation proceeded in high yields on unprotected amino acids and peptides containing a sulfhydryl group.
Method Of Synthesizing S-Allyl-Cysteine Analogues And Their Therapeutic Application In Treating Myocardial Infarction
申请人:ZHU YIZHUN
公开号:US20090036534A1
公开(公告)日:2009-02-05
A pharmaceutical composition and methods of producing and application of the composition for treating myocardial infarction of a subject are disclosed. The pharmaceutical composition comprises a therapeutically effective amount of at least one synthesized compound selected from the group consisting of SEC, SPC, SBC, SPEC, SAC, SAMC, and SPRC, and a pharmaceutically acceptable carrier.
Influence of Sulfoxide Group Placement on Polypeptide Conformational Stability
作者:Eric G. Gharakhanian、Ehab Bahrun、Timothy J. Deming
DOI:10.1021/jacs.9b07223
日期:2019.9.18
The synthesis of a homologous series containing five new non-ionic sulfoxide containing polypeptides was described. Sulfoxide groups bestowed water solubility for all homologs, which allowed their use as a model for study of helix-coil transitions in water while avoiding contributions from charged groups or phase separation. Polypeptides were found to adopt chain conformations in water that were dependent
In Vitro Biogeneration of Pure Thiosulfinates and Propanethial-<i>S</i>-oxide
作者:Cunxi Shen、Kirk L. Parkin
DOI:10.1021/jf000711g
日期:2000.12.1
derived from a single ACSO, and a preparation containing a mixture of four thiosulfinate species was derived from reaction mixtures employing binary ACSO substrate systems. Identities of homologous thiosulfinates and PTSO were confirmed by 1H NMR. This approach has the potential to be used as a preparative tool for yielding pure thiosulfinates and PTSO to facilitate the study of chemical and biological properties
开发了一个模型反应系统,使用分离的蒜氨酸酶(EC 4.4.1.4)和分离的或合成的烷基(烯)基-L-半胱氨酸亚砜(ACSO)生成纯硫代亚磺酸盐和丙烷硫氧化物(PTSO)。在21-23摄氏度下3小时后,反应收率范围为30%至60%,并将有机硫反应产物萃取到CHCl3中,以制得具有受控组成的产物制剂。纯的硫代亚磺酸盐或PTSO来源于单一的ACSO,而含有四种硫代亚磺酸盐物质的混合物的制备则来自采用二元ACSO底物系统的反应混合物。同源硫代亚磺酸盐和PTSO的身份通过1 H NMR确认。