| Abstract
| - Spectrofluorimetry experiments using synthetic trisaccharides indicate that in compounds that display affinity for antithrombin III (AT-III), a unique trisaccharide sequence plays the key role in the early recognition, and the first step of AT-III activation. Added to previous observations, these new results suggest that the two-step binding mechanism previously proposed (Olson et al., J. Biol. Chem., 1981, 256, 11073-11079) might involve, in the first place, a conformational change of the protein, induced by the trisasaccharide →4)-O-(6-O-sulfo-2-sulfoamino-2-deoxy-α- D -glucopyranosyl)-(1→4)-O-(β-D-glucopyranosyluronic acid)-(1→4) -O- (3,6- di -O-sulfo-2-sulfoamino-2-deoxy-α-D- glucopyranosyl)-(1→, then would follow the fitting which ends in the locked complex. These observations support the new paradigm invoking specific oligosacchande sequences in selective interactions of glycosaminoglycans and proteins.
|
