IGFBP-3 and IGFBP-5 association with endothelial cells: role of C-terminal heparin binding domain.
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.
Booth
B A
BA
Veterans Administration Medical Center, Department of Internal Medicine, Iowa City 52246, USA.
Boes
M
M
Andress
D L
DL
Dake
B L
BL
Kiefer
M C
MC
Maack
C
C
Linhardt
R J
RJ
Bar
K
K
Caldwell
E E
EE
Weiler
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000378:metabolism*; D002417:Cattle; D002704:Chlorates / Q000494:pharmacology; D002845:Chromatography; D004730:Endothelium, Vascular / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D006031:Glycosylation; D006493:Heparin / Q000378:metabolism*; D019763:Heparin Lyase; D006497:Heparan Sulfate / Q000378:metabolism; D018975:Insulin-Like Growth Factor Binding Protein 5; D018969:Insulin-Like Growth Factor Binding Proteins; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D011133:Polysaccharide-Lyases / Q000494:pharmacology; D011479:Protamines / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism
D002352:Carrier Proteins; D002704:Chlorates; D006025:Glycosaminoglycans; D006493:Heparin; D019763:Heparin Lyase; D006497:Heparan Sulfate; D018975:Insulin-Like Growth Factor Binding Protein 5; D018969:Insulin-Like Growth Factor Binding Proteins; D010446:Peptide Fragments; D011133:Polysaccharide-Lyases; D011479:Protamines; D013431:Sulfates; C032706:sodium chlorate