title: gamma-Glutamyltranspeptidase from Proteus mirabilis: localization and activation by phospholipids.
abstract: Antiserum was prepared against the purified gamma-glutamyltranspeptidase (EC 2.3.2.2) of Proteus mirabilis. The antiserum inactivated the gamma-glutamyltranspeptidase activities of both purified enzyme and intact cells. Native cells were agglutinated with the antibody. Immunocytochemical studies with indirect immunofluorescence and electron microscopy analysis suggested that gamma-glutamyltranspeptidase is localized on the surface of the cell. Its distribution in the cell wall or periplasmic space or both was also confirmed by the treatment of cells with lysozyme-EDTA. The purified enzyme was activated by the addition of membrane phospholipids isolated from the same bacterium. The hydrolysis activity was stimulated more than the transpeptidation activity by several phospholipids.
mesh_terms: D004789:Enzyme Activation; D007106:Immune Sera; D005779:Immunodiffusion; D007700:Kinetics; D008854:Microscopy, Electron; D010743:Phospholipids / Q000494:pharmacology* / Q000502:physiology; D011513:Proteus mirabilis / Q000201:enzymology* / Q000648:ultrastructure; D005723:gamma-Glutamyltransferase / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D007106:Immune Sera; D010743:Phospholipids; D005723:gamma-Glutamyltransferase