Open AccessAmphibian lutropin from the bullfrog Rana catesbeiana
Author(s) -
HAYASHI Hiroaki,
HAYASHI Tomoko,
HANAOKA Yoichi
Publication year - 1992
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1992.tb16756.x
Subject(s) - bullfrog , cyanogen bromide , protein subunit , amphibian , biology , biochemistry , protein primary structure , peptide sequence , rana , amino acid , microbiology and biotechnology , chemistry , endocrinology , ecology , gene
The amino acid sequence of lutropin (LH) β subunit of an amphibian, the bullfrog Rana catesbeiana , has been determined. The primary structure was determined by sequencing the intact protein (residues 1–44) and peptides originated by cyanogen bromide cleavage and lysyl endopeptidase digestion. 12 cysteine residues are conserved in the bullfrog and mammalian LH β subunit. One sugar‐chain‐binding site at Asn‐8 is also conserved in the bullfrog and in all mammals except humans. This glycoprotein is composed of 112 amino acid residues with a molecular mass of 12675 Da, considering the six cystine bridges and excepting the sugar chain. The bullfrog β subunit has approximately 50% sequence identity with that of mammals and with the fish gonadotropin β subunit, and about 40% with bullfrog follicle‐stimulating hormone β subunit.