IUBMB Enzyme Nomenclature


Accepted name: cyanophycinase

Reaction: [L-Asp(4-L-Arg)]n + H2O = [L-Asp(4-L-Arg)]n-1 + L-Asp(4-L-Arg)

For diagram click here.

Glossary: cyanophycin = [L-Asp(4-L-Arg)]n = N-β-aspartylarginine = [L-4-(L-arginin-2-N-yl)aspartic acid]n = poly{N4-[(1S)-1-carboxy-4-guanidinobutyl]-L-asparagine}

Other name(s): cyanophycin degrading enzyme; β-Asp-Arg hydrolysing enzyme; CGPase; CphB; CphE; cyanophycin granule polypeptidase; extracellular CGPase

Comments: The enzyme is highly specific for the branched polypeptide cyanophycin and does not hydrolyse poly-L-aspartate or poly-L-arginine [3]. A serine-type exopeptidase that belongs in peptidase family S51.

Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, PDB, CAS registry number:


1. Obst, M., Krug, A., Luftmann, H. and Steinbüchel, A. Degradation of cyanophycin by Sedimentibacter hongkongensis strain KI and Citrobacter amalonaticus strain G isolated from an anaerobic bacterial consortium. Appl. Environ. Microbiol. 71 (2005) 3642-3652. [PMID: 16000772]

2. Obst, M., Oppermann-Sanio, F.B., Luftmann, H. and Steinbüchel, A. Isolation of cyanophycin-degrading bacteria, cloning and characterization of an extracellular cyanophycinase gene (cphE) from Pseudomonas anguilliseptica strain BI. The cphE gene from P. anguilliseptica BI encodes a cyanophycin-hydrolyzing enzyme. J. Biol. Chem. 277 (2002) 25096-25105. [PMID: 11986309]

3. Richter, R., Hejazi, M., Kraft, R., Ziegler, K. and Lockau, W. Cyanophycinase, a peptidase degrading the cyanobacterial reserve material multi-L-arginyl-poly-L-aspartic acid (cyanophycin): molecular cloning of the gene of Synechocystis sp. PCC 6803, expression in Escherichia coli, and biochemical characterization of the purified enzyme. Eur. J. Biochem. 263 (1999) 163-169. [PMID: 10429200]

[EC created 2007]

Return to EC 3.4.15 home page
Return to EC 3.4 home page
Return to EC 3 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page