Direct identification of a novel disulfide bond linkage system of new isolated isomer (isomer V) in recombinantly produced h-IGF-I.
Insulin-like growth factor I (IGF-I or somatomedin C) is a serum polypeptide with three intramolecular disulfide bonds. In the course of synthesis by the recombinant DNA method, three disulfide bond isomers, all of which have Cys18-Cys61 with three combinations of two disulfide bonds formed by Cys6, Cys47, Cys48 and Cys52, were identified. Natural type, isomer II, was proved to have a Cys6-Cys48, Cys18-Cys61, Cys47-Cys52 disulfide bond system. Now, the fourth isomer, isomer V which doesn't have Cys18-Cys61 disulfide, has been isolated, and its novel disulfide bond linkage system was identified by a chemical synthetic method. The supposed conformation constrained in 3D structure for isomer V would be discussed for its biological activity.
Iwai
M
M
Marine Technical College, Faculty of Liberal Arts and Science, Ashiya, Hyogo, Japan. iwai@libe.mtc.ac.jp
Yokoyama
H
H
Yamada
H
H
Niwa
M
M
Kobayashi
M
M
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000737:chemistry; D006801:Humans; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000737:chemistry; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000737:chemistry; D007334:Insulin-Like Growth Factor I / Q000737:chemistry*; D007536:Isomerism; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry
D004220:Disulfides; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I