Human neurophysins--isolation by high performance liquid chromatography from different extracts.

Different extraction methods, incomplete data on their amino acid composition and different designations according to their electrophoretic mobility result in a still somewhat unclear picture of the human neurophysins. In respect to the limited amount of human material we compared the traditional extraction method with extraction procedures after removal of either HGH or of the proopiocortin-peptides. The purification of these extracts by high performance liquid chromatography resulted in an identical pattern of six neurophysin peaks. They all showed the typical characteristics of the neurophysins. According to their amino acid composition they represent two groups of neurophysins. The analysis of the peaks 4--6 is similar to the amino acid composition of neurophysin I; the main compositional characteristics of the peaks 1--3 are those of neurophysin II. However, sequencing work is needed, before the picture in the human neurophysins will be clarified.