Peptides reproducing the ApoA-I 141-164 region: Studies on Hpt recognition

P 229 PEPTIDES REPRODUCING THE APOA-I 141-164 REGION:STUDIES ON HPT RECOGNITIONL. D. D'Andrea,1 M. S. Spagnuolo,2 A. De Stefano,1 M. Morra,1 A.Carlucci,2 A. Del Gatto,2 P. Caso,2 C. Pedone1 P. Abrescia2 and E.Benedetti21Istituto di Biostrutture e Bioimmagini, CNR, Napoli, 80134, Italy2Dipartimento delle Scienze Biologiche, Universita` degli Studi diNapoli "Federico II", Napoli, 80134, ItalyApolipoprotein A-I (ApoA-I) is the major component of the high density lipoproteins (HDL) which are involved in the reverse cholesterol transport. In particular, ApoA-I stimulates the efflux of cholesterol from cell toward HDL activating the enzyme lecithin-cholesterol acyltransferase (LCAT). It has been demonstrated that the protein haptoglobin(Hpt) binds to ApoA-I [1] and inhibits the ApoA-I-dependent activity of LCAT [2]. Hpt is one of the most abundant proteins in the plasma and its level increases during inflammation processes. Previously, we have mapped the Hpt-binding site of Apo A-I to the sequence 141-164 and demonstrated that peptides reproducing this site competewith ApoA-I for binding to Hpt and restore the LCAT activity in the presence of Hpt [3]. Here we report the molecular bases of the ApoAI/Hpt recognition using peptides reproducing the ApoA-I sequence 141-164.[1] Kunitake, S.T., Carilli, C.T., Lau, K., Protter, A.A., Naya-Vigne,J., Kane, J.P. Biochemistry 33, 1988 (1994).[2] Balestrieri, M., Cigliano, L., De Simone, M.L., Dale, B., Abrescia,P. Mol. Reprod. Dev. 59, 186 (2001).[3] Spagnuolo, M.S., Cigliano, L., D'Andrea, L.D., Pedone, C.,Abrescia P. J. Biol. Chem., 280, 1193 (2005).