Publications & Reports

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.

Marinaro JA, Jamieson GP, Hogarth PM, Bach LA
University of Melbourne, Department of Medicine, Austin and Repatriation Medical Centre, Heidelberg, Vic, Australia.

Abstract

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 approximately 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.

Publication

  • Journal: FEBS Letters
  • Published: 07/05/1999
  • Volume: 450
  • Issue: 3
  • Pagination: 240-244

Authors