Search Results

You are looking at 1 - 1 of 1 items for

  • Author: F. Shibayama x
  • Refine by access: All content x
Clear All Modify Search
K. Tamura
Search for other papers by K. Tamura in
Google Scholar
PubMed
Close
,
M. Kobayashi
Search for other papers by M. Kobayashi in
Google Scholar
PubMed
Close
,
S. Suzuki
Search for other papers by S. Suzuki in
Google Scholar
PubMed
Close
,
Y. Ishii
Search for other papers by Y. Ishii in
Google Scholar
PubMed
Close
,
S. Koyama
Search for other papers by S. Koyama in
Google Scholar
PubMed
Close
,
H. Yamada
Search for other papers by H. Yamada in
Google Scholar
PubMed
Close
,
K. Hashimoto
Search for other papers by K. Hashimoto in
Google Scholar
PubMed
Close
,
M. Niwa
Search for other papers by M. Niwa in
Google Scholar
PubMed
Close
, and
F. Shibayama
Search for other papers by F. Shibayama in
Google Scholar
PubMed
Close

ABSTRACT

Monoclonal antibodies (McAb) and polyclonal antibodies (PcAb) against human insulin-like growth factor-I (somatomedin C; hIGF-I) were produced. Using these two antibodies, an enzyme-linked immunosorbent assay (ELISA) system for hIGF-I was established. The ELISA system was able to detect hIGF-I at a range of 1–25 μg/l, compared with the range of 1–50 μg/l detected by radioimmunoassay (RIA). Human IGF-II and human insulin could not be recognized in this system. The plasma concentrations of IGF-I found using the ELISA agreed well with those found using RIA after conventional Sep-Pak C18 cartridge pretreatment. Epitopes of hIGF-I to McAb and PcAb were investigated by enzymatic digestion of hIGF-I followed by comparing the affinity of the antibodies to the peptides obtained proteolytically. The epitope to McAb was found to be a peptide containing Leu10-Val11-Asp12 (epitope 2). Five epitopes to PcAb containing the following key fragments were identified: a conformational structure formed by the disulphide bonds between Cys6 and Cys48, and between Cys47 and Cys52 (epitope 1), Leu10-Val11-Asp12 (epitope 2), Val17-Cys18-Gly19-Asp20 (epitope 3), Arg21-Gly22-Phe23-Tyr24 (epitope 4) and Lys68-Ser69-Ala70 (epitope 5). Of these, the peptide containing epitope 5 showed the highest affinity to PcAb. The results indicated that our ELISA system combined recognition by epitope 2 of McAb and recognition by epitope 5 of PcAb to obtain its good specificity.

Journal of Endocrinology (1990) 125, 327–335

Restricted access