Gonadotropin-releasing hormone-associated peptide immunoreactivity in bovine colostrum.
Gonadotropin-releasing hormone(GnRH)-associated peptide (GAP) is a 56-amino acid peptide found on the C-terminal of the GnRH (also called luteinizing hormone-releasing hormone) precursor and is assumed to be co-produced with GnRH. The purpose of this report is to demonstrate the presence of GAP immunoreactivity in bovine colostrum. Radioimmunoassay of acidified methanolic extracts demonstrated a concentration of GAP immunoreactivity of approximately 1.5 +/- 0.1 pmol/g dry skim bovine colostrum. Gel filtration (Sephadex G-10) and high-performance liquid chromatography of extracts containing GAP immunoreactivity showed it to be of low molecular weight and a high hydrophobic character. The presence of GAP immunoreactivity in bovine colostrum suggests that the GnRH precursor is synthesized and processed in mammary tissue itself.
Zhang
T
T
Laboratory of Bioorganic Chemistry, School of Pharmaceutical Sciences, University of Shizyoka, Japan.
Iguchi
K
K
Mochizuki
T
T
Hoshino
M
M
Yanaihara
C
C
Yanaihara
N
N
D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003126:Colostrum / Q000032:analysis*; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis*; D008970:Molecular Weight; D011498:Protein Precursors / Q000032:analysis*; D011863:Radioimmunoassay
D011498:Protein Precursors; C050502:gonadotropin releasing hormone associated peptide; D007987:Gonadotropin-Releasing Hormone