A phospholipid substrate molecule residing in the membrane surface mediates opening of the lid region in group IVA cytosolic phospholipase A2.

ABSTRACT: The Group IVA (GIVA) phospholipase A(2) associates with natural membranes in response to an increase in intracellular Ca(2+) along with increases in certain lipid mediators. This enzyme associates with the membrane surface as well as binding a single phospholipid molecule in the active site for catalysis. Employing deuterium exchange mass spectrometry, we have identified the regions of the protein binding the lipid surface and conformational changes upon a single phospholipid binding in the absence of a lipid surface. Experiments were carried out using natural palmitoyl arachidonyl phosphatidylcholine vesicles with the intact GIVA enzyme as well as the isolated C2 and catalytic domains. Lipid binding produced changes in deuterium exchange in eight different regions of the protein. The regi

SUBMITTER: Burke JE 

PROVIDER: S-EPMC2576534 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature