Cyanogen Bromide Cleavage and Partial Amino Acid Sequence of Porcine Growth Hormone

Porcine growth hormone has been cleaved with cyanogen bromide and the resulting fragments separated by gel filtration. The amino acid sequences of the amino-terminal tetrapeptide (Fragment D), the carboxy-terminal dodecapeptide (Fragment C), and another polypeptide of 55 residues (Fragment B) are reported. Preliminary chemical evidence and comparison with the primary structure of human growth hormone indicate that Fragment B is adjacent to Fragment C in native porcine growth hormone. There is at least 67% homology between pig and human growth hormones in the carboxy-terminal third of the molecules.