EC 22.214.171.124 - Bleomycin hydrolase
IntEnz Enzyme Nomenclature
- Inactivates bleomycin B2 (a cytotoxic glycometallopeptide) by hydrolysis of a carboxyamide bond of β-aminoalanine, but also shows general aminopeptidase activity. The specificity varies somewhat with source, but amino acid arylamides of Met, Leu and Ala are preferred .
The molecule is a homohexamer in which the monomers have a papain-like tertiary structure (in peptidase family C1). The active sites are on the walls of a central channel through the molecule, and access of substrate molecules to them is obstructed by this and by the C-terminus of each polypeptide chain . Bleomycin can scarcely be the natural substrate, and there are reports of limited endopeptidase activity. Known from bacteria as well as eukaryotic organisms. Hydrolase H from chicken muscle has many similarities to bleomycin hydrolase, but hydrolyses Ph-CO-Arg-2-naphthylamine as well as aminopeptidase substrates .
Links to other databases
Human bleomycin hydrolase: molecular cloning, sequencing, functional expression, and enzymatic characterization.Biochemistry 35: 6706-6714 (1996). [PMID: 8639621]
cDNA cloning and expression of chicken aminopeptidase H, possessing endopeptidase as well as aminopeptidase activity.Eur. J. Biochem. 245: 283-288 (1997). [PMID: 9151954]
The unusual active site of Gal6/bleomycin hydrolase can act as a carboxypeptidase, aminopeptidase, and peptide ligase.Cell 93: 103-109 (1998). [PMID: 9546396]
Catalytic properties of the cysteine aminopeptidase PepC, a bacterial bleomycin hydrolase.Biochim. Biophys. Acta 1383: 63-70 (1998). [PMID: 9546047]
[EC 126.96.36.199 created 2000]