Isolation and characterisation of a novel peptide from ostrich adenohypophyses.

A novel peptide has been isolated from ostrich pituitary glands using acid acetone extraction, salt fractionation, ion exchange and gel permeation chromatography and preparative paper electrophoresis. The homogeneous fraction contained a large proportion of hydrophobic amino acids apparently concentrated in a portion of the polypeptide. An amino-terminal isoleucine and carboxyl-terminal glutamine were found. The molecular weight was determined as 15 024 (ultracentrifugation) and 16 185 (amino acid analysis). A single intra-molecular disulfide bond was determined. The isoelectric point was 6.5. A possible role as part of a hormone precursor is suggested.