Preparation of biologically active and site specifically radioiodinated recombinant human insulin-like growth factor-I.
Recombinant human insulin-like growth factor-I (rhIGF-I) was iodinated using a lactoperoxidase-catalyzed labeling method. The labeled products were separated into more than five fractions by ion-paired reverse-phase high performance liquid chromatography (HPLC). A fraction (peak 1), which showed the highest yield and radioactivity, was found to be biologically active in the BALB/c 3T3 cell proliferating system. The site of the iodination was investigated by S-pyridylethylation followed by trypsinization and separation with HPLC using reverse phase columns. From the amino acid analysis of the peaks which were radioactive, the iodination site of peak 1 was revealed to be Tyr-24 and Tyr-60. This is the first report of the biological activity of radioactive peptide hormone with a defined labeled site.
Kohama
Y
Y
Faculty of Pharmaceutical Sciences, Osaka University, Japan.
Okabe
M
M
Tsujikawa
K
K
Oka
H
H
Teramoto
T
T
Kayamori
Y
Y
Itoh
M
M
Mimura
T
T
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000737:chemistry* / Q000494:pharmacology; D007457:Iodine Radioisotopes / Q000737:chemistry*; D007553:Isotope Labeling; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology
D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I