Chemical Properties of Equine Pituitary Follicle-Stimulating Hormone1

Abstract

Purified equine pituitary follicle stimulating hormone (FSH) was analyzed for protein and carbohydrate contents, amino acid composition, and NH2- and COOH—terminal amino acid residues. The results indicate that equine FSH is a glycoprotein having 74.9% protein, 9.3% hexose, 9.1% hexosamine, 4.7% sialic acid and 1.3% fucose. The amino acid composition was characterized by high levels of half—cystine, threonine, lysine and aspartic and glutamic acids, and a low level of methionine. Phenylalanine and aspartic acid were identified as NH2—terminal amino acids while the COOH—terminal residues were found to be isoleucine and glutamic acid. (Endocrinology91: 1418, 1972)