Booth B A, Boes M, Andress D L, Dake B L, Kiefer M C, Maack C, Linhardt R J, Bar K, Caldwell E E, Weiler J
Veterans Administration Medical Center, Department of Internal Medicine, Iowa City 52246, USA.
Growth Regul. 1995 Mar;5(1):1-17.
IGFBP-3 and IGFBP-5, but not the other 4 IGF binding proteins, specifically bound to endothelial cell (EC) monolayers. Charged compounds, such as heparin and heparan sulfate, competed for this binding. Of the 6 IGFBPs, IGFBP-3 and IGFBP-5 had the greatest heparin affinity. Peptides of 18 amino acids were synthesized, corresponding to a common basic region of IGFBP-3 (P3), IGFBP-5 and IGFBP-6 (P6) which contained a heparin binding sequence. P3 and P6 inhibited IGFBP-3 and -5 binding to endothelial cell monolayers and the peptides bound directly to EC extracellular matrix. This suggested that the C-terminal basic segment of IGFBP-3/-5 is important for the association of the binding protein with the EC monolayer.
胰岛素样生长因子结合蛋白3（IGFBP-3）和胰岛素样生长因子结合蛋白5（IGFBP-5），而非其他4种胰岛素样生长因子结合蛋白，可特异性结合至内皮细胞（EC）单层。带电荷的化合物，如肝素和硫酸乙酰肝素，可竞争这种结合。在6种胰岛素样生长因子结合蛋白中，IGFBP-3和IGFBP-5具有最强的肝素亲和力。合成了18个氨基酸的肽段，其对应于IGFBP-3（P3）、IGFBP-5和IGFBP-6（P6）的一个共同碱性区域，该区域包含肝素结合序列。P3和P6抑制IGFBP-3和-5与内皮细胞单层的结合，且这些肽段可直接结合至EC细胞外基质。这表明IGFBP-3/-5的C末端碱性片段对于结合蛋白与EC单层的结合很重要。
