Procholeragenoid

《英文msh詞典》Procholeragenoid
[入口詞] Procholeragenoid
[主題詞] Cholera Toxin
[藥動學] Adjuvants,Immunologic
[英文釋義] An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers,the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells,and facillitate the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.