Where is pepsinogen created

The signal peptide is cleaved as the protein is inserted into endoplasmic reticulum and the resulting proenzyme - pepsinogen - is transported to the Golgi and condensed into secretory granules. Pepsinogens are secreted in a form such that the activation peptide assumes a compact structure that occludes the active site. On exposure to an acidic pH the activation peptide is cleaved, thereby unmasking the active site and generating catalytically-active pepsin.

Optimal activity of pepsins is at pH of 1. They are reversibly inactivated at about pH 5 and irreversibly inactivated at pH 7 to 8. In general, secretion of pepsinogens is coupled to secretion of acid from the parietal cell. In vitro studies have demonstrated that secretion is effectively stimulated by agents that stimulate either of two conditions:. Receptors for many of the hormones listed above have been demonstrated on chief cells and pepsinogen secretion has been stimulated or blocked by exposure to these agents or their antagonists, respectively.

Peptides may be further digested by other proteases in the duodenum and eventually absorbed by the body. Pepsin is stored as pepsinogen so it will only be released when needed, and does not digest the body's own proteins in the stomach's lining.

Pepsin functions best in acidic environments because it is found in an acidic environment, particularly those in a pH of 1. Other important digestive proteases are the pancreatic enzymes trypsin and chymotrypsin. Pepsin denatures if the pH is more than 5.

Pepsin is potently inhibited by the peptide inhibitor pepstatin. Autolysis may also be prevented by storage of pepsins at pH 11 or by using pepsins modified by e. When the pH is adjusted back to pH 6 activity returns. Category : EC 3. Read what you need to know about our industry portal bionity.

My watch list my. My watch list My saved searches My saved topics My newsletter Register free of charge. Keep logged in. Cookies deactivated. To use all functions of this page, please activate cookies in your browser. Login Register. Home Encyclopedia Pepsin Pepsin.

Additional recommended knowledge. Topics A-Z. All topics. To top. About bionity. Your browser is not current. Microsoft Internet Explorer 6. Your browser does not support JavaScript. To use all the functions on Chemie.