Chitosanase
| Chitosanase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 3.2.1.132 | ||||||||
| CAS no. | 51570-20-8 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Chitosanase (EC 3.2.1.132) is an enzyme with systematic name chitosan N-acetylglucosaminohydrolase.[1][2][3][4] This enzyme catalyses the following chemical reaction
- Endohydrolysis of beta-(1->4)-linkages between D-glucosamine residues (GlcN-GlcN) in a partly acetylated chitosan
A whole spectrum of chitosanases are known.
Promiscuity
[edit]Chitosanases can be divided into four classes by the extent of their enzyme promiscuity:[5]
- Cleaves GlcNAc-GlcN and GlcN-GlcN;
- Cleaves only GlcN-GlcN;
- Cleaves GlcN-GlcNAc and GlcN-GlcN;
- Cleaves a wide variety of β-glycosidic bonds except GlcNAc-GlcNAc (one that cleaves GlcNAc-GlcNAc would be instead considered a promiscuous endo-chitinase).
Under the CAZy classification of glycoside hydrolases, chitosanase activity mostly occurs in GH5, GH7, GH8, GH46, GH75, and GH80.[5]
- GH5 is a very large family. Some promiscuous enzymes in this family digest both carboxymethyl cellulose (CMC) [or cellulose] and chitosan.[5]
- GH7 is where most cellulases and cellulose 1,4-beta-cellobiosidases reside. A few cellulases/cellobiosidases in this family are additionally able to digest chitosan. No pure chitosanases have been identified in this family.[5]
- Most of GH8 is promiscuous. Hydrolyzable substrates in addition to chitosan may include CMC, cellulose, lichenan, and (unspecified) β-glucan.[5]
- GH46 is mostly specific to chitosan due to a conserved highly electronegative substrate-binding cleft, but one example that also digests cellulose has been found.[5]
- GH75 and GH80 are only known to be specific.[5]
References
[edit]- ↑ Fenton DM, Eveleigh DE (1981). "Purification and mode of action of a chitosanase from Penicillium islandicum". J. Gen. Microbiol. 126: 151–165. doi:10.1099/00221287-126-1-151.
- ↑ Saito J, Kita A, Higuchi Y, Nagata Y, Ando A, Miki K (October 1999). "Crystal structure of chitosanase from Bacillus circulans MH-K1 at 1.6-A resolution and its substrate recognition mechanism". The Journal of Biological Chemistry. 274 (43): 30818–25. doi:10.1074/jbc.274.43.30818. PMID 10521473.
- ↑ Izume M, Nagae S, Kawagishi H, Mitsutomi M, Ohtakara A (March 1992). "Action pattern of Bacillus sp. no. 7-M chitosanase on partially N-acetylated chitosan". Bioscience, Biotechnology, and Biochemistry. 56 (3): 448–53. doi:10.1271/bbb.56.448. PMID 1368330.
- ↑ Marcotte EM, Monzingo AF, Ernst SR, Brzezinski R, Robertus JD (February 1996). "X-ray structure of an anti-fungal chitosanase from streptomyces N174". Nature Structural Biology. 3 (2): 155–62. doi:10.1038/nsb0296-155. PMID 8564542.
- 1 2 3 4 5 6 7 Su, H; Sun, J; Jia, Z; Zhao, H; Mao, X (November 2022). "Insights into promiscuous chitosanases: the known and the unknown". Applied Microbiology and Biotechnology. 106 (21): 6887–6898. doi:10.1007/s00253-022-12198-1. PMID 36178516.
External links
[edit]- Chitosanase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
