Cystalysin, a 46-kDa L-cysteine desulfhydrase from Treponema denticola: Biochemical and biophysical characterization

Lianrui Chu, Jeffery L. Ebersole, Gary P. Kurzban, Stanley C. Holt

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

A 46-kDa hemolytic protein referred to as cystalysin, from Treponema denticola ATCC 35404, was characterized and overexpressed in Escherichia coli LC-67. Cystalysin lysed erythrocytes, hemoxidized hemoglobin to sulfhemoglobin and methemoglobin, and removed the sulfhydryl and amino group from selected S-containing compounds (e.g., cysteine) producing H2S, NH3, and pyruvate. With L-cysteine as substrate, cystalysin obeys Michaelis- Menten kinetics. Cystathionine and s-aminoethyl-L-cysteine were also substrates. Several of the small alpha amino acids were found to be competitive inhibitors of cystalysin. The enzymatic activity was increased by β-mercaptoethanol and was not inhibited by the proteinase inhibitor TLCK (Nα-p-tosyl-L-lysine chloromethyl ketone), pronase, or proteinase K, suggesting the functional site was physically protected or located in a small fragment of the polypeptide. We hypothesize that cystalysin is a pyridoxal- 5-phosphate-containing enzyme with the activity of an αC-N and βC-S lyase (cystathionase). Since high amounts of H2S have been reported in deep periodontal pockets, this metabolic enzyme from T. denticola may also function in vivo as an important virulence molecule.

Original languageEnglish (US)
Pages (from-to)442-450
Number of pages9
JournalClinical Infectious Diseases
Volume28
Issue number3
DOIs
StatePublished - 1999

ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases

Fingerprint Dive into the research topics of 'Cystalysin, a 46-kDa L-cysteine desulfhydrase from Treponema denticola: Biochemical and biophysical characterization'. Together they form a unique fingerprint.

Cite this