Chymosine
370905
29872845
2008-05-22T22:54:41Z
Pixeltoo
12024
! pov
La '''chymosine''' ou '''rennine''' (ne pas confondre avec [[rénine]]) est une [[endopeptidase]] ({{N° EC|3.4.23.4}}) du suc gastrique des veaux, des nouveau-nés... permettant la digestion ''spécifique'' de la [[caséine]].
Pour fabriquer les fromages, on ajoute au [[lait]] de la chymosine de veau.<!--, or for making [[junket]]--> Cette enzyme réagit spécifiquement avec la κ-[[caséine]] à la surface des [[micelle]]s de caséine du lait, coupant la protéine entre la [[phénylalanine]] et la [[méthionine]]. Ceci en présence d'ions [[calcium]] provoque la coagulation des micelles de caséine, donnant un [[caillé]].
<!-- The soluble fragment (residules 106-169) which becomes part of the [[whey]] is known as [[glyco macro peptide]] and contains the [[glycosylation]] sites for kappa casein. The other component (residules 1-105) is insoluble.
The traditional source of rennet is the [[abomasum]] (fourth [[stomach]]) of [[slaughter]]ed, milk-fed new-born [[calf|calves]] or other young [[ruminant]]s. It is also possible to produce rennet from [[fungus|fungi]]. In recent times, most commercial rennet is made from genetically modified [[yeast]] or [[bacterium|bacteria]], allowing the production of cheese that is considered [[vegetarian]]. This rennet is thought to yield greater consistency in cheese quality than traditional animal rennet. Another rennet substitute ''cynara'' (from wild thistle) is used in traditional cheese production throughout the [[Mediterranean]].
Sometimes, the terminology is more distinct, '''rennet''' being the stomach extract, while '''rennin''' or '''chymosin''' are names for the pure enzyme itself, which is the active ingredient in the extract.-->
==Voir aussi==
* [[pepsine]]
* [[présure]]
== Liens externes==
* {{en}} http://www.vegsoc.org/info/cheese.html
* {{en}} [[Banque de données des protéines|PDB]] [http://www.rcsb.org/pdb/cgi/explore.cgi?pid=203441034360021&page=0&pdbId=1CMS 1CMS], bovine chymosin
[[Catégorie:EC 3.4.23]]
[[de:Chymosin]]
[[en:Chymosin]]
[[fi:Renniini]]
[[is:Rennín]]
[[it:Chimosina]]