Editing Chitinase (section)

== Function ==
Like cellulose, chitin is an abundant biopolymer that is relatively resistant to degradation.<ref name=Akaki1>{{cite journal |journal=Journal of Experimental Zoology |vauthors=Akaki C, Duke GE |year=2005 |volume=283 |issue=4–5 |pages=387–393 |title=Apparent chitin digestibilities in the Eastern screech owl (''Otus asio'') and the American kestrel (''Falco sparverius'') |doi=10.1002/(SICI)1097-010X(19990301/01)283:4/5<387::AID-JEZ8>3.0.CO;2-W}}</ref> Many mammals can digest chitin and the specific chitinase levels in vertebrate species are adapted to their feeding behaviours.<ref name="pmid29362395">{{cite journal | vauthors = Tabata E, Kashimura A, Kikuchi A, Masuda H, Miyahara R, Hiruma Y, Wakita S, Ohno M, Sakaguchi M, Sugahara Y, Matoska V, Bauer PO, Oyama F | display-authors = 6 | title = Chitin digestibility is dependent on feeding behaviors, which determine acidic chitinase mRNA levels in mammalian and poultry stomachs | journal = Scientific Reports | volume = 8 | issue = 1 | pages = 1461 | date = January 2018 | pmid = 29362395 | pmc = 5780506 | doi = 10.1038/s41598-018-19940-8 | bibcode = 2018NatSR...8.1461T }}</ref> Certain fish are able to digest chitin.<ref name="pmid15556391">{{cite journal | vauthors = Gutowska MA, Drazen JC, Robison BH | title = Digestive chitinolytic activity in marine fishes of Monterey Bay, California | journal = Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology | volume = 139 | issue = 3 | pages = 351–8 | date = November 2004 | pmid = 15556391 | doi = 10.1016/j.cbpb.2004.09.020 | citeseerx = 10.1.1.318.6544 }}</ref> Chitinases have been isolated from the stomachs of mammals, including humans.<ref name="pmid17587796">{{cite journal | vauthors = Paoletti MG, Norberto L, Damini R, Musumeci S | title = Human gastric juice contains chitinase that can degrade chitin | journal = Annals of Nutrition & Metabolism | volume = 51 | issue = 3 | pages = 244–51 | year = 2007 | pmid = 17587796 | doi = 10.1159/000104144 | s2cid = 24837500 }}</ref>

Chitinase activity can also be detected in human [[blood]]<ref name="pmid7836450">{{cite journal | vauthors = Renkema GH, Boot RG, Muijsers AO, Donker-Koopman WE, Aerts JM | title = Purification and characterization of human chitotriosidase, a novel member of the chitinase family of proteins | journal = The Journal of Biological Chemistry | volume = 270 | issue = 5 | pages = 2198–202 | date = February 1995 | pmid = 7836450 | doi = 10.1074/jbc.270.5.2198 | doi-access = free | hdl = 1887/50684 | hdl-access = free }}</ref><ref name="pmid7591134">{{cite journal | vauthors = Escott GM, Adams DJ | title = Chitinase activity in human serum and leukocytes | journal = Infection and Immunity | volume = 63 | issue = 12 | pages = 4770–3 | date = December 1995 | doi = 10.1128/IAI.63.12.4770-4773.1995 | pmid = 7591134 | pmc = 173683 | url = }}</ref> and possibly [[cartilage]].<ref name="Hakala1">{{cite journal | vauthors = Hakala BE, White C, Recklies AD | title = Human cartilage gp-39, a major secretory product of articular chondrocytes and synovial cells, is a mammalian member of a chitinase protein family | journal = The Journal of Biological Chemistry | volume = 268 | issue = 34 | pages = 25803–10 | date = December 1993 | doi = 10.1016/S0021-9258(19)74461-5 | pmid = 8245017 | doi-access = free }}</ref>  As in plant chitinases this may be related to pathogen resistance.<ref name="pmid12071845">{{cite journal | vauthors = Recklies AD, White C, Ling H | title = The chitinase 3-like protein human cartilage glycoprotein 39 (HC-gp39) stimulates proliferation of human connective-tissue cells and activates both extracellular signal-regulated kinase- and protein kinase B-mediated signalling pathways | journal = The Biochemical Journal | volume = 365 | issue = Pt 1 | pages = 119–26 | date = July 2002 | pmid = 12071845 | pmc = 1222662 | doi = 10.1042/BJ20020075 }}</ref><ref name="Eijk1">{{cite journal | vauthors = van Eijk M, van Roomen CP, Renkema GH, Bussink AP, Andrews L, Blommaart EF, Sugar A, Verhoeven AJ, Boot RG, Aerts JM | title = Characterization of human phagocyte-derived chitotriosidase, a component of innate immunity | journal = [[International Immunology]] | volume = 17 | issue = 11 | pages = 1505–12 | date = November 2005 | pmid = 16214810 | doi = 10.1093/intimm/dxh328 | doi-access = free }}</ref>