Abstract
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.
Publication types
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Binding Sites
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Binding, Competitive
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Carrier Proteins / metabolism*
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Cattle
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Chlorates / pharmacology
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Chromatography
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Endothelium, Vascular / metabolism*
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Extracellular Matrix / metabolism
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Glycosaminoglycans / metabolism
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Glycosylation
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Heparin / metabolism*
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Heparin Lyase
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Heparitin Sulfate / metabolism
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Insulin-Like Growth Factor Binding Protein 5
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Insulin-Like Growth Factor Binding Proteins
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Molecular Sequence Data
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Peptide Fragments / chemistry
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Peptide Fragments / metabolism*
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Polysaccharide-Lyases / pharmacology
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Protamines / metabolism
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Sulfates / metabolism
Substances
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Carrier Proteins
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Chlorates
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Glycosaminoglycans
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Insulin-Like Growth Factor Binding Protein 5
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Insulin-Like Growth Factor Binding Proteins
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Peptide Fragments
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Protamines
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Sulfates
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Heparin
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Heparitin Sulfate
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Polysaccharide-Lyases
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Heparin Lyase
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sodium chlorate