Immunoreactive prohormone atrial natriuretic peptides 1-30 and 31-67; existence of a single circulating amino-terminal peptide.
Sep-Pak C18 extraction of human plasma and radioimmunoassay using antibodies which recognize atrial natriuretic peptide (99-128) and the prohormone sequences 1-30 and 31-67 resulted in mean values from 20 normal subjects of 26.2 (+/- 9.2), 362 (+/- 173) and 368 (+/- 160) pg/ml, respectively. A high correlation coefficient between values obtained using antibodies recognizing prohormone sequences 1-30 and 31-67 was observed (R = 0.84). Extracted plasma immunoreactivity of 1-30 and 31-67 both eluted at 46% acetonitrile. In contrast, chromatographic elution of synthetic peptides 1-30 and 31-67 was observed at 48 and 39% acetonitrile, respectively. Data suggest that the radioimmunoassay of plasma using antibodies recognizing prohormone sequences 1-30 and 31-67 may represent the measurement of a unique larger amino-terminal peptide fragment containing antigenic sites recognized by both antisera.
Chen
Y M
YM
NASA/Johnson Space Center, Biomedical Laboratories Branch, Houston, TX 77058.
Whitson
P A
PA
Cintrón
N M
NM
D009320:Atrial Natriuretic Factor / Q000276:immunology*; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D006801:Humans; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D011498:Protein Precursors / Q000276:immunology*; D011863:Radioimmunoassay
D010455:Peptides; D011498:Protein Precursors; D009320:Atrial Natriuretic Factor