Membrane-docking loops of the cPLA2 C2 domain: detailed structural analysis of the protein-membrane interface via site-directed spin-labeling.

ABSTRACT: C2 domains are protein modules found in numerous eukaryotic signaling proteins, where their function is to target the protein to cell membranes in response to a Ca(2+) signal. Currently, the structure of the interface formed between the protein and the phospholipid bilayer is inaccessible to high-resolution structure determination, but EPR site-directed spin-labeling can provide a detailed medium-resolution view of this interface. To apply this approach to the C2 domain of cytosolic phospholipase A(2) (cPLA(2)), single cysteines were introduced at all 27 positions in the three Ca(2+)-binding loops and labeled with a methanethiosulfonate spin-label. Altogether, 24 of the 27 spin-labeled domains retained Ca(2+)-activated phospholipid binding. EPR spectra of these 24 labeled domains obtained

SUBMITTER: Malmberg NJ 

PROVIDER: S-EPMC3637888 | biostudies-literature | 2003 Nov

REPOSITORIES: biostudies-literature