Premium
Differential dissociation kinetics explain the binding preference of insulin‐like growth factor binding protein‐6 for insulin‐like growth factor‐II over insulin‐like growth factor‐I
Author(s) -
Marinaro Joe A.,
Jamieson Gary P.,
Hogarth P.Mark,
Bach Leon A.
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00499-8
Subject(s) - kinetics , insulin , insulin like growth factor , growth factor , insulin like growth factor binding protein , chemistry , dissociation (chemistry) , receptor–ligand kinetics , endocrinology , biochemistry , biology , physics , receptor , quantum mechanics
Insulin‐like growth factor binding protein‐6 binds insulin‐like growth factor‐II with a marked preferential affinity over insulin‐like growth factor‐I. The kinetic basis of this binding preference was studied using surface plasmon resonance. Binding of insulin‐like growth factor‐I and insulin‐like growth factor‐II to immobilized insulin‐like growth factor binding protein‐6 fitted a two‐site binding kinetic model. Insulin‐like growth factor‐I and insulin‐like growth factor‐II association rates were similar whereas the dissociation rate was ∼60‐fold lower for insulin‐like growth factor‐II, resulting in a higher equilibrium binding affinity for insulin‐like growth factor‐II. The equilibrium binding affinities of a series of insulin‐like growth factor‐II mutants were also explained by differential dissociation kinetics. O ‐glycosylation had a small effect on the association kinetics of insulin‐like growth factor binding protein‐6. The insulin‐like growth factor binding properties of insulin‐like growth factor binding protein‐6 are explained by differential dissociation kinetics.