NMR solution structure of complement-like repeat CR3 from the low density lipoprotein receptor-related protein. Evidence for specific binding to the receptor binding domain of human alpha(2)-macroglobulin.Dolmer, K., Huang, W., Gettins, P.G.
(2000) J Biol Chem 275: 3264-3269
- PubMed: 10652313
- DOI: 10.1074/jbc.275.5.3264
- Primary Citation of Related Structures:
- PubMed Abstract:
We have used NMR methods to determine the structure of the calcium complex of complement-like repeat 3 (CR3) from the low density lipoprotein receptor-related protein (LRP) and to examine its specific interaction with the receptor binding domain of human ...
We have used NMR methods to determine the structure of the calcium complex of complement-like repeat 3 (CR3) from the low density lipoprotein receptor-related protein (LRP) and to examine its specific interaction with the receptor binding domain of human alpha(2)-macroglobulin. CR3 is one of eight related repeats that constitute a major ligand binding region of LRP. The structure is very similar in overall fold to homologous complement-like repeat CR8 from LRP and complement-like repeats LB1, LB2, and LB5 from the low density lipoprotein receptor and contains a short two-strand antiparallel beta-sheet, a one turn alpha-helix, and a high affinity calcium site with coordination from four carboxyls and two backbone carbonyls. The surface electrostatics and topography are, however, quite distinct from each of these other repeats. Two-dimensional (1)H,(15)N-heteronuclear single quantum coherence spectra provide evidence for a specific, though relatively weak (K(d) approximately 140 microM), interaction between CR3 and human alpha2-macroglobulin receptor binding domain that involves a contiguous patch of surface residues in the central region of CR3. This specific interaction is consistent with a mode of LRP binding to ligands that uses contributions from more than one domain to generate a wide array of different binding sites, each with overall high affinity.
Department of Biochemistry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612-4316, USA.