title: Antiserum developed for the E peptide region of insulin-like growth factor IA prohormone recognizes a serum protein by both immunoblot and radioimmunoassay.
abstract: 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.
authors.affiliation: Department of Pediatrics, Stanford University Medical Center, California 94305.
authors.forename: D R
authors.initials: DR
authors.lastname: Powell
authors.forename: P D
authors.initials: PD
authors.lastname: Lee
authors.forename: D
authors.initials: D
authors.lastname: Chang
authors.forename: F
authors.initials: F
authors.lastname: Liu
authors.forename: R L
authors.initials: RL
authors.lastname: Hintz
mesh_terms: D001798:Blood Proteins / Q000276:immunology*; D006801:Humans; D007106:Immune Sera / Q000276:immunology*; D007158:Immunologic Techniques; D007334:Insulin-Like Growth Factor I / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology*; D011863:Radioimmunoassay; D013002:Somatomedins / Q000276:immunology*; D014511:Uremia / Q000097:blood
chemical_list: D001798:Blood Proteins; D007106:Immune Sera; D010446:Peptide Fragments; D013002:Somatomedins; C053766:insulin-like growth factor 1A prohormone (91-103); D007334:Insulin-Like Growth Factor I