Heidaran M A, Yu J C, Jensen R A, Pierce J H, Aaronson S A
Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892.
J Biol Chem. 1992 Feb 15;267(5):2884-7.
32D cells transfected with the human alpha platelet-derived growth factor receptor (alpha PDGFR) bind PDGF-AA, -AB, and -BB isoforms with high affinity, and the binding of each can be efficiently competed by all three isoforms. In an effort to develop better understanding of spatial relationships of binding sites for PDGF-AA and -BB, we constructed an alpha PDGFR mutant which deleted amino acids 150-189 within its extracellular domain. This mutant showed a marked decrease in high affinity binding sites for PDGF-AA without comparable alteration in affinity for PDGF-BB. These findings imply that the high affinity binding sites for PDGF-AA and PDGF-BB in the alpha PDGFR extracellular domain are not structurally coincident.
用人类α血小板衍生生长因子受体（α PDGFR）转染的32D细胞以高亲和力结合PDGF - AA、- AB和 - BB亚型，并且这三种亚型中的每一种都能有效竞争彼此的结合。为了更好地理解PDGF - AA和 - BB结合位点的空间关系，我们构建了一个α PDGFR突变体，该突变体缺失了其细胞外结构域内的150 - 189位氨基酸。该突变体显示出PDGF - AA高亲和力结合位点显著减少，而对PDGF - BB的亲和力没有类似改变。这些发现表明，α PDGFR细胞外结构域中PDGF - AA和PDGF - BB的高亲和力结合位点在结构上并不重合。
