Luteinizing Hormone

The sequences of the 119 amino acids of bovine and porcine luteinizing hormone β‐subunits were determined, 17 amino acid replacements being observed between these species. Variability in the primary structure was observed for porcine β‐subunit, in that position 10 is occupied by both arginyl and glutamyl residues. No free amino terminal residue was detected for both porcine and bovine β‐polypeptide chains and both exhibited carboxy‐terminal heterogeneity. The homology of the β‐subunits of luteinizing hormone from various species and the β‐subunit of the bovine thyroid‐stimulating hormone is discussed as the subunit of both hormones can combine with a similar α‐subunit.