Faculty Collaboration Database

Recombinant glutathione S-transferase/CD36 fusion proteins define an oxidized low density lipoprotein-binding domain. J Biol Chem 1998 Dec 25;273(52):34875-81

Date

12/18/1998

Pubmed ID

9857015

DOI

10.1074/jbc.273.52.34875

Scopus ID

2-s2.0-0032567491 (requires institutional sign-in at Scopus site)   53 Citations

Abstract

CD36 is a multifunctional cell-surface receptor that binds adhesion molecules such as thrombospondin-1 and collagen and modified lipids and/or lipoproteins. It participates in cellular uptake of photoreceptor outer segments and scavenging of apoptotic cells and oxidized low density lipoprotein (Ox-LDL). Recognition and internalization of Ox-LDL by mononuclear phagocytes may play an important role in the development of atherosclerotic lesions. We have utilized a series of recombinant bacterial glutathione S-transferase/CD36 fusion proteins that span nearly all of the CD36 molecule to characterize the structural domain on CD36 that recognizes Ox-LDL. We found that the Ox-LDL-binding domain is different from the thrombospondin-1-binding domain located at amino acids 93-120. A fusion protein containing the region extending from amino acids 5 to 143 formed specific, saturable, and reversible complexes with Ox-LDL. As with intact CD36, binding was blocked by excess unlabeled Ox-LDL and antibodies to CD36. The stoichiometry and affinity of the fusion protein for Ox-LDL were similar to those of the intact protein. We also demonstrated that this fusion protein competitively inhibited binding of Ox-LDL to purified platelet CD36 and to CD36 expressed on peripheral blood monocytes and CD36 cDNA-transfected melanoma cells. The use of smaller peptides and fusion proteins including those spanning amino acids 28-93 and 5-93 has further narrowed the binding site to a region from amino acids 28 to 93, although participation of a sequence in the noncontiguous region 120-155 cannot be excluded. This study, for the first time, demonstrates unique regions of the scavenger receptor CD36 that bind the Ox-LDL ligand. Our structural analysis of the receptor provides information as to potential control of the trafficking of modified lipoproteins into the blood vessel wall.

Author List

Pearce SF, Roy P, Nicholson AC, Hajjar DP, Febbraio M, Silverstein RL

Author

Roy L. Silverstein MD Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Binding Sites
Biological Transport
Blood Platelets
CD36 Antigens
Glutathione Transferase
Humans
Lipoproteins, LDL
Macrophages
Monocytes
Peptide Fragments
Protein Binding
Recombinant Fusion Proteins
Thrombospondin 1