Purification of a high molecular weight somatomedin binding protein from human plasma.
The somatomedins insulin-like growth factor I and II (1,2) are in serum bound to high-molecular weight binding proteins (6,7,8). By use of a four step chromatographic procedure a somatomedin binding protein was isolated from outdated human plasma. Exclusion chromatography on Sephadex G-200 disclosed a molecular weight of 150 kDa. After lyophilization however, the binding activity was found in a lower molecular weight range of 35-45 kDa. A partial amino acid sequence analysis of the lyophilized material revealed a possible N-terminal sequence of Ala-Pro-Trp. This sequence is identical to the N-terminal sequence of the 35 kDa somatomedin binding protein previously isolated from human amniotic fluid (16).
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D002352:Carrier Proteins / Q000302:isolation & purification*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D008970:Molecular Weight; D013002:Somatomedins / Q000378:metabolism*
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins