Skip Navigation


Journal of Biochemistry Advance Access originally published online on November 1, 2007
Journal of Biochemistry 2008 143(1):59-68; doi:10.1093/jb/mvm194
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
143/1/59    most recent
mvm194v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Kong, Y.
Right arrow Articles by Shen, X.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kong, Y.
Right arrow Articles by Shen, X.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2007 The Japanese Biochemical Society.

Enzymatic Characterization and Inhibitor Discovery of a New Cystathionine {gamma}-Synthase from Helicobacter pylori

Yunhua Kong1,{dagger}, Dalei Wu1,{dagger}, Haiyun Bai1, Cong Han1, Jing Chen1, Lili Chen1, Lihong Hu1,2,{ddagger}, Hualiang Jiang1,2 and Xu Shen1,2,*

1Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203; and 2School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China

*To whom correspondence should be addressed. Tel: +86-21-50806918, Fax: +86-21-50806918, E-mail: xshen{at}mail.shcnc.ac.cn

Received September 9, 2007; Accepted October 1, 2007


  Abstract

Cystathionine {gamma}-synthase (CGS) catalyses the first step of the transsulfuration pathway that converts L-cysteine to L-homocysteine in bacteria, whereas this pathway is absent in human. In this report, we identified a new metB gene from Helicobacter pylori strain SS1, and the recombinant H. pylori Cystathionine {gamma}-synthase (HpCGS) was successfully cloned, expressed and purified in Escherichia coli system. Enzymatic study of HpCGS indicated that the Km and kcat/Km values against the substrate O-succinyl-L-homoserine (L-OSHS) were 3.02 mM and 98.7 M–1s–1, respectively. Moreover, four natural products ({alpha}-lapachone, 9-hydroxy-{alpha}-lapachone, Paulownin and Yangambin, Fig. 1) were discovered to demonstrate inhibitory activities against HpCGS with IC50 values of 11 ± 3, 9 ± 1, 19 ± 2 and 27 ± 6 µM, respectively. All these four inhibitors prevent the binding of L-OSHS to HpCGS in a non-competitive fashion. In vitro antibacterial assays further indicated that these four discovered compounds could highly inhibit the growth of H. pylori and exhibited strong inhibitory specificity against H. pylori related to E. coli.

Key Words: cystathionine {gamma}-synthase, Helicobacter pylori, inhibitor, inhibitor type, minimum inhibition concentration, transsulfuration

Abbreviations: CGS, cystathionine {gamma}-synthase; HpCGS, Helicobacter pylori cystathionine {gamma}-synthase; EcCGS, E. coli cystathionine {gamma}-synthase; L-OSHS, O-Succinyl-L-homoserine; HO-HxoDH, D-2-Hydroxyisocaproate Dehydrogenase; MIC, minimum inhibition concentration; APPA, DL-E-2-amino-5-phosphono-3-pentenoic acid; PPCA, 3-(phosphonomethyl)pyridine-2-carboxylic acid; CTCPO, 5-carboxymethylthio-3-(3'-chlorophenyl)-1,2,4-oxadiazol; Ni-NTA, nickel-nitrilotriacetic acid; PCR, polymerase chain reaction

{dagger} These authors contributed equally to this work.

{ddagger} Correspondence may also be addressed. E-mail: simmhulh{at}mail.shcnc.ac.cn


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.