RT Journal Article
SR Electronic
T1 THE ISOLATION OF A PROTEIN FROM THE PARS NEURALIS OF THE OX PITUITARY WITH CONSTANT OXYTOCIC, PRESSOR AND DIURESIS-INHIBITING ACTIVITIES
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 190
OP 209
VO 74
IS 2
A1 H. B. VAN DYKE
A1 BACON F. CHOW
A1 R. O. GREEP
A1 ALEXANDRE ROTHEN
YR 1942
UL http://jpet.aspetjournals.org/content/74/2/190.abstract
AB The isolation of a protein from frozen posterior lobes of oxen is described. It appears to be pure so far as this can be demonstrated by constant solubility and by "schlieren" patterns in the ultracentrifuge. Although some inhomogeneity was found in the Tiselius electrophoresis apparatus, reasons are given for believing this to be derived from a pure protein. The molecular weight is about 30,000. The isoelectric point is about pH 4.8. Empirical analysis revealed an unusually high percentage of S (4.9 per cent) which is almost entirely present as part of cystine. Oxytocic, vasopressor, and diuresis-inhibiting activities are all present in ratios resembling those of U.S.P. reference standard. Ten micrograms of nitrogen or 61 micrograms of solids are approximately equivalent to 1 U.S.P. unit. Experiments designed to demonstrate that the oxytocic and vasopressor activities are moieties chemically united with the protein are described. Reduction of the cystine in the protein by thioglycollic acid nearly abolishes the activity. In this respect cysteine is much less effective.