Antiserum developed for the e peptide region of insulin-like growth factor ia prohormone recognizes a serum protein by both immunoblot and radioimmunoassay

David R. Powell, Phillip D.K. Lee, Ding Chang, Frances Liu, Raymond L. Hintz

Research output: Contribution to journalArticle

40 Scopus citations


Nucleotide sequencing of the two known cDNAs encoding human insulin-like growth factor I (IGF-I) predicts two different prohormone forms of IGF-I. The predicted prohormone amino acid sequences (E peptide regions) extend the carboxy-terminus of IGF-I by either an additional 35 (IGF-IA) or 77 (IGF-IB) amino acids. We developed an antiserum directed against a synthetic peptide which is unique to the E peptide region of IGF-IA prohormone. In a RIA using this antiserum, synthetic E peptide immunoreactivity was found in the serum of patients with chronic renal failure. The protein recognized by this antiserum has a mol wt of about 13, 000 by neutral gel filtration and about 19, 000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. These data suggest that the E peptide region of the IGF-IA prohormone is expressed and circulates as part of the prohormone.

Original languageEnglish (US)
Pages (from-to)868-875
Number of pages8
JournalJournal of Clinical Endocrinology and Metabolism
Issue number5
StatePublished - Nov 1987
Externally publishedYes


ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical

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