Chymosin (CYM)

Chymosin, also known as rennin, is a proteolytic enzyme belonging to the aspartic protease family, primarily found in the gastric juice of neonatal ruminants such as calves (UniProt: P00794). Its fundamental biological role is to facilitate the digestion of milk by specifically cleaving the Phe105-Met106 peptide bond of kappa-casein, which results in the coagulation or curdling of milk (PubChem: CID 119689). In humans, the chymosin gene (CYM) is a pseudogene located on chromosome 1, meaning it does not produce a functional protein in the human body; instead, pepsin performs the primary gastric proteolytic functions (NCBI: Gene ID 1458). Consequently, chymosin is not considered a therapeutic target for human diseases and has no known role in human pathology. However, it is extensively utilized in the food industry for cheese production and serves as a biochemical model for studying other medically relevant aspartic proteases like renin and HIV-1 protease (Wikipedia: Chymosin).

Other names

RenninGalantaseRennaseAspartic proteaseMilk-clotting enzyme

Chymosin catalyzes the hydrolysis of the Phe105-Met106 peptide bond in kappa-casein, leading to the destabilization of casein micelles and subsequent milk curdling (PubChem: CID 119689).