[Study of the protein-peptide composition of secretory granules of bovine lactogenic hormone].

A combination of gel chromatography, fluorimetric analysis and polyacrylamide gel electrophoresis with immunochemical identification, the protein-peptide composition of secretory granules of the lactogenic hormone (LTH) isolated from the anterior lobe of bovine hypophysis was investigated. It was found that the peptide content of the granules is less than 3% of that of immunoreactive LTH. Using gel chromatography, the secretory granules were found to contain a hormone monomer and two immunoreactive forms with Mr 42 and 64 kD. With respect to immunoreactivity, the hormone form content was 90, 3 and 7%, respectively. Using polyacrylamide gel electrophoresis and subsequent immunochemical identification, the presence of four immunoreactive forms of LTH were identified in the secretory granules.