“Stoichiometry of Lipid-Protein Interaction Assessed by Hydrophobic Photolabeling¨

VILLAMIL GIRALDO A.M; CASTELLO PR,; GONZÁLEZ FLECHA FL; MOELLER, J.V; DELFINO JM; ROSSI JPFC

FEBS LETTERS

Elsevier

Lugar: Amsterdam; Año: 2006 vol. 580 p. 607 - 612

0014-5793

FEBS Lett. 2006 Apr 3;580(8):2158.Stoichiometry of lipid-protein interaction assessed by hydrophobic photolabeling.Villamil Giraldo AM, Castello PR, Gonzalez Flecha FL, Moeller JV, Delfino JM, Rossi JP.Instituto de Quimica y Fisicoquimica Biologicas, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Junin 956.C1113AAD, Buenos Aires, Argentina.Here we undertook a comparative study of the composition of the lipid annulus of three ATPases pertaining to the P-type family: plasma membrane calcium pump (PMCA), sarcoplasmic reticulum calcium pump (SERCA) and Na,K-ATPase. The photoactivatable phosphatidylcholine analogue [(125)I]TID-PC/16 was incorporated into mixtures of dimyristoyl phosphatidylcholine (DMPC) and each enzyme with the aid of the nonionic detergent C(12)E(10). After photolysis, the extent of the labeling reaction was assessed to determine the lipid:protein stoichiometry: 17 for PMCA, 18 for SERCA, 24 for the Na,K-ATPase (alpha-subunit) and 5.6 mol PC/mol protein for the Na,K-ATPase (beta-subunit).