Isolation of a biologically active fragment from the carboxy terminus of the fetal rat binding protein for insulin-like growth factors.
We have purified a 14 kDa fragment of the 30 kDa binding protein for insulin-like growth factors (IGFs) from BRL-3A cell conditioned medium. The fragment binds IGF-I and IGF-II with similar specificity to the 30 kDa binding protein, but with lower affinity. It corresponds to the carboxy terminus of the native binding protein (residues 148-270), and is thought to arise by proteolysis. We infer that this region of the native binding protein contains, at least in part, the IGF binding domain.
Wang
J F
JF
Molecular, Cellular and Nutritional Endocrinology Branch, National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, MD 20892.
Hampton
B
B
Mehlman
T
T
Burgess
W H
WH
Rechler
M M
MM
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents; D003470:Culture Media; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D011972:Receptor, Insulin / Q000302:isolation & purification* / Q000378:metabolism; D017451:Receptors, Somatomedin; D013002:Somatomedins / Q000378:metabolism*; D013329:Structure-Activity Relationship
D003432:Cross-Linking Reagents; D003470:Culture Media; D010446:Peptide Fragments; D017451:Receptors, Somatomedin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D011972:Receptor, Insulin