Limited proteolysis
The Limited proteolysis is a term used in biochemistry and physiology , and the elimination referred individual peptide fragments from a large precursor peptide. In the body, inactive enzyme precursors are turned into active enzymes. This type of proteolysis is limited because only very specific fragments can and must be split off in order to obtain a functional protein.
Another form of limited proteolysis is the cleavage of the signal sequence from export proteins, ie proteins that a cell synthesizes for “outside”; This includes both secretion proteins (e.g. insulin ) and cell membrane proteins in the rough endoplasmic reticulum .
Large parts of the blood coagulation cascade proceed via the activation of enzymes through limited proteolysis. And also many hormones (e.g. renin ) are proteases that turn precursor proteins (e.g. angiotensinogen ) into active peptide hormones (e.g. angiotensin I ) by splitting off . In the pancreas, the limited proteolysis prevents the organ from digesting itself, as the inactive precursor trypsinogen is only converted to the protein-splitting enzyme trypsin by the enteropeptidase of the small intestinal mucosa .
Individual evidence
- ↑ Ulf Dettmer et al .: Intensive course in biochemistry. Elsevier, Urban & Fischer, 2005. ISBN 9783437444500 . P. 38f.