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 RECOGNITION L. 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. Benedetti2 1Istituto di Biostrutture e Bioimmagini, CNR, Napoli, 80134, Italy 2Dipartimento delle Scienze Biologiche, Universita` degli Studi di Napoli "Federico II", Napoli, 80134, Italy Apolipoprotein 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 compete with 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).