Preparation of Biologically Active and Site Specifically Radioiodinated Recombinant Human Insulin-like Growth Factor-I

Yasuhiro Kohama, Ma Sar U. Okabe, Kazutake Tsujikawa, Hiroaki Oka, Tetsuyuki Teramoto, Yuzo Kayamor, M. Masaaki, Tsutomu Mimura

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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.

Original languageEnglish
Pages (from-to)808-810
Number of pages3
JournalChemical and Pharmaceutical Bulletin
Issue number3
Publication statusPublished - Jan 1 1992


All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Drug Discovery

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