Editing Trypsin (section)

== Properties ==
Human trypsin has an optimal [[operating temperature]] of about 37&nbsp;°C.<ref>{{cite journal | vauthors = Chelulei Cheison S, Brand J, Leeb E, Kulozik U | title = Analysis of the effect of temperature changes combined with different alkaline pH on the β-lactoglobulin trypsin hydrolysis pattern using MALDI-TOF-MS/MS | journal = Journal of Agricultural and Food Chemistry | volume = 59 | issue = 5 | pages = 1572–81 | date = March 2011 | pmid = 21319805 | doi = 10.1021/jf1039876 | bibcode = 2011JAFC...59.1572C }}</ref>  In contrast, the [[Atlantic cod]] has several types of trypsins for the [[poikilotherm]] fish to survive at different body temperatures. Cod trypsins include trypsin I with an activity range of {{convert|4|to|65|C|F}} and maximal activity at {{convert|55|°C|°F|abbr=on}}, as well as trypsin Y with a range of {{convert|2|to|30|C|F}} and a maximal activity at {{convert|21|°C|°F|abbr=on}}.<ref>{{cite journal | vauthors = Gudmundsdóttir A, Pálsdóttir HM | title = Atlantic cod trypsins: from basic research to practical applications | journal = Marine Biotechnology | volume = 7 | issue = 2 | pages = 77–88 | year = 2005 | pmid = 15759084 | doi = 10.1007/s10126-004-0061-9 | bibcode = 2005MarBt...7...77G | s2cid = 42480996 }}</ref>

As a protein, trypsin has various molecular weights depending on the source. For example, a molecular weight of 23.3 kDa is reported for trypsin from bovine and porcine sources.

The activity of trypsin is not affected by the [[enzyme inhibitor]] tosyl phenylalanyl chloromethyl ketone, [[tosyl phenylalanyl chloromethyl ketone|TPCK]], which deactivates [[chymotrypsin]].

Trypsin should be stored at very cold temperatures (between &minus;20 and &minus;80&nbsp;°C) to prevent [[Autolysis (biology)|autolysis]], which may also be impeded by storage of trypsin at pH 3 or by using trypsin modified by [[reductive methylation]]. When the pH is adjusted back to pH 8, activity returns.