Chymosin
67167
212152696
2008-05-13T17:32:10Z
68.210.12.103
{{protein
|Name=Chymosin [Precursor] (''B.taurus'' or ''C.dromedarius'')
|caption=
|image=
|width=
|HGNCid=
|Symbol=CYM
|AltSymbols=CPC
|EntrezGene=529879
|OMIM=
|RefSeq=NP_851337.1
|UniProt=Q9GK11
|PDB=4CMS
|ECnumber=3.4.23.4
|Chromosome=3
|Arm=
|Band=
|LocusSupplementaryData=
}}
{{protein
|Name=chymosin pseudogene (''H.sapiens'')
|caption=
|image=
|width=
|HGNCid=2588
|Symbol=CYMP
|AltSymbols=
|EntrezGene=1542
|OMIM=118943
|RefSeq=
|UniProt=
|PDB=
|ECnumber=3.4.23.4
|Chromosome=1
|Arm=
|Band=
|LocusSupplementaryData=
}}
'''Chymosin''' (or '''rennin''') is an [[Aspartic acid proteases|aspartic acid protease]] [[enzyme]] found in [[rennet]]. It is produced by the cow, in the lining of the [[abomasum]] (its fourth stomach).
Bovine chymosin is produced nowadays recombinantly in ''[[E.coli]]'', ''[[Aspergillus niger |Aspergillus niger var awamori]]'', and ''[[K.lactis]]'' as alternative resource to the one from the cows.
The gene is found in humans (on [[chromosome 1]]), but it is not in a functioning form.
Rennin is produced by gastric chief cells in infants to curdle the milk they ingest, allowing a longer residence in the bowels and better absorption.
==Enzymatic reaction==
It causes [[cleavage]] of a specific linkage, the [[peptide bond]] between [[phenylalanine]] and [[methionine]] in the [[K-casein]]. If this reaction applies to milk, the specific linkage between the [[hydrophobic]] (para-casein) and [[hydrophilic]] (acidic [[glycopeptide]]) group of [[casein]] inside milk would be broken, since they are joined by phenylalanine and methionine. The hydrophobic group would unite together and would form a [[Three-dimensional space|3D]] network to trap the aqueous phase of the milk. The resultant product is [[calcium phosphocaseinate]].
Due to this reaction, rennin is used to bring about the extensive [[Precipitation (chemistry)|precipitation]] and [[curd]] formation in [[cheese]] making.
[[de:Chymosin]]
[[fr:Chymosine]]
[[is:RennĂn]]
[[it:Chimosina]]
[[fi:Renniini]]