Further biochemical characterization of the polyneuropeptide h3 recently isolated from human brain material, and its identification in human liver.

ABSTRACT

Recently (1) we reported the isolation and partial biochemical characterization of a novel polypeptide from human brain. Now we report the isolation of an almost identical polypeptide from human liver tissue and further biochemical characterization of both polypeptides. Thorough analytical investigation with several methods, fully described hereafter, of both polypeptides, leads on the one hand to a more complete picture of the polypeptide and on the other hand to the correction of earlier assumptions. The monomeric polypeptide, now identified as a glycopolypeptide, is indeed an independent chain of approximately 220 amino-acid residues and possesses 2 free sulphydryl groups. From the almost complete identity between the CNS and liver polypeptide it is concluded that they are most probably one and the same polypeptide and consequently, that h3 is not brain specific.