title: Circular dichroic studies of protein kinase C and its interactions with calcium and lipid vesicles.
abstract: Circular dichroism was used to study the secondary structure of protein kinase C (PKC) in aqueous solution and the conformational changes resulting due to the presence of its regulatory cofactors (e.g. Ca2+, phosphatidylserine (PS) and phorbol 12-myristate 13-acetate (PMA)). Computer analysis of the CD data for the estimates of secondary structure showed that PKC maintains a highly ordered structure containing 36% alpha-helix, 57% beta-sheet and 7% beta-turn. PKC displays a minor conformational change upon addition of Ca2+. However, a larger change is observed on adding phosphatidylserine vesicles in the presence of Ca2+. In this case, the alpha-helix content is decreased by approx. 35% and beta-sheet increased by approx. 16%. The protein does not experience further significant changes in conformation on adding PMA.
authors.affiliation: Department of Biophysics, Boston University School of Medicine, Housman Medical Research Center, MA 02118.
authors.forename: J
authors.initials: J
authors.lastname: Shah
authors.forename: G G
authors.initials: GG
authors.lastname: Shipley
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002417:Cattle; D002942:Circular Dichroism; D008081:Liposomes; D008433:Mathematics; D008970:Molecular Weight; D010718:Phosphatidylserines / Q000378:metabolism* / Q000494:pharmacology; D011485:Protein Binding; D011487:Protein Conformation; D011493:Protein Kinase C / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000378:metabolism / Q000494:pharmacology
chemical_list: D008081:Liposomes; D010718:Phosphatidylserines; D000255:Adenosine Triphosphate; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium