Structural study on ligand specificity of human vitamin B12 transporters.

ABSTRACT: Studies comparing the binding of genuine cobalamin (vitamin B12) to that of its natural or synthetic analogues have long established increasing ligand specificity in the order haptocorrin, transcobalamin and intrinsic factor, the high-affinity binding proteins involved in cobalamin transport in mammals. In the present study, ligand specificity was investigated from a structural point of view, for which comparative models of intrinsic factor and haptocorrin are produced based on the crystal structure of the homologous transcobalamin and validated by results of published binding assays. Many interactions between cobalamin and its binding site in the interface of the two domains are conserved among the transporters. A structural comparison suggests that the determinant of specificity regardin

SUBMITTER: Wuerges J 

PROVIDER: S-EPMC1876373 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature