Lambda toxin (Clostridium perfringens)

Akinobu Okabe, Osamu Matsushita

Research output: Chapter in Book/Report/Conference proceedingChapter


This chapter discusses the structural chemistry and the biological aspects of lambda toxin. The deduced protein sequence of λ-toxin comprises three portions which include a signal sequence, a pro sequence, and the mature enzyme. Four enzymes belonging to the same M4 peptidase family, Bacillus thermoproteolyticus thermolysin, Bacillus cereus neutral protease, Pseudomonas aeruginosa elastase, have been shown to have closely related tertiary structures. Each enzyme consists of two domains in common which include an N-terminal domain rich in antiparallel β strands, and a C-terminal domain rich in a helices. There is a deep cleft between these domains, and the first two α helices of the C-terminal domain form the bottom of the cleft and act as ligands for a zinc ion and a substrate water molecule. λ-Toxin can degrade immunoglobulin G, complement C3 component, fibrinogen, fibronectin and α2-macroglobulin, which contribute to innate or adaptive immune defense against infection. This implies a pathogenic role, as suggested for many proteases produced by pathogenic bacteria. Intradermal injection of the purified λ-toxin into mice causes hemorrhagic edema by increasing vascular permeability.

Original languageEnglish
Title of host publicationHandbook of Proteolytic Enzymes, Second Edition
Subtitle of host publicationVolume 1: Aspartic and Metallo Peptidases
Number of pages3
ISBN (Electronic)9780120796113
ISBN (Print)9780124121058
Publication statusPublished - Jan 1 2004
Externally publishedYes

ASJC Scopus subject areas

  • General Biochemistry,Genetics and Molecular Biology


Dive into the research topics of 'Lambda toxin (Clostridium perfringens)'. Together they form a unique fingerprint.

Cite this