Competition for binding to insulin-like growth factor (IGF) binding protein-2, 3, 4, and 5 by the IGFs and IGF analogs.

摘要: The insulin-like growth factors (IGF) I and II bind to IGF binding proteins (BP) with high affinity. affinity of each the IGFs for individual BPs regions IGF-I molecule that are required this have been defined only IGFBP-1 IGFBP-3. present studies determined several analogs (prepared using in vitro mutagenesis) pure IGFBP-2, 3, 4, 5. results show IGFBP-2 binds these a manner similar IGFBP-1. For example, mutation A chain region (positions 49, 50, 51) or B 4) greater than 20-fold reduction either 2. In contrast, mutations minimal effect on IGFBP-3, whereas substitutions at 15, 16 positions reduce by least 50-fold. At pH 7.4, IGFBP-4 is less affected 4 compared IGFBP-1, 2, ...