|
|
||||||||
Research Paper |
,ß-elimination activity that degrades L-cysteine
Department of Preventive Dentistry, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan1
Author for correspondence: Yoshio Nakano. Tel: +81 92 642 6423. Fax: +81 92 642 6354. e-mail: yosh{at}dent.kyushu-u.ac.jp
Hydrogen sulfide is highly toxic to mammalian cells. It has also been postulated that hydrogen sulfide modifies haemoglobin resulting in haemolysis. The enzyme that produces hydrogen sulfide from L-cysteine was purified from Streptococcus anginosus. Using the N-terminal amino acid sequence of the purified enzyme, the lcd gene encoding L-cysteine desulfhydrase was cloned; the recombinant protein was then purified to examine its enzymic and biological characteristics. This L-cysteine desulfhydrase had the MichaelisMenten kinetics Km=0·62 mM and Vmax=163 µmol min-1 mg-1. DL-Cystathionine, L-cystine, S-(2-aminoethyl)-L-cysteine, 3-chloro-DL-alanine and S-methyl-L-cysteine were substrates for the enzyme, whereas D-cysteine, DL-homocysteine, L-methionine, DL-serine, DL-alanine, L-cysteine methyl ester, L-tryptophan, L-tyrosine and L-phenylalanine were not. These findings suggest that this L-cysteine desulfhydrase is a C-S lyase that catalyses the
,ß-elimination (
C-N and ßC-S) reaction. In addition, it is demonstrated that the hydrogen sulfide produced by this enzyme caused the modification and release of haemoglobin in sheep erythrocytes.
Keywords: L-cysteine desulfhydrase, hydrogen sulfide
Abbreviations: RBC, sheep erythrocyte
The DDBJ accession number for the Streptococcus anginosus lcd gene sequence reported in this paper is AB084812.
a
Deceased, October 14, 2001. This paper is in recognition of his fine work and is dedicated to his memory.
This article has been cited by other articles:
![]() |
S. Irmler, S. Raboud, B. Beisert, D. Rauhut, and H. Berthoud Cloning and Characterization of Two Lactobacillus casei Genes Encoding a Cystathionine Lyase Appl. Envir. Microbiol., January 1, 2008; 74(1): 99 - 106. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. C. Martinez-Cuesta, C. Pelaez, J. Eagles, M. J. Gasson, T. Requena, and S. B. Hanniffy YtjE from Lactococcus lactis IL1403 Is a C-S Lyase with {alpha},{gamma}-Elimination Activity toward Methionine. Appl. Envir. Microbiol., July 1, 2006; 72(7): 4878 - 4884. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Sperandio, P. Polard, D. S. Ehrlich, P. Renault, and E. Guedon Sulfur Amino Acid Metabolism and Its Control in Lactococcus lactis IL1403 J. Bacteriol., June 1, 2005; 187(11): 3762 - 3778. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |