A New Method for the Purification of Arginase

Abstract

The arginase purification method of Mohamed and Greenberg yielded a product which, according to electrophoretic data, was a composite of 3 or 4 constituents. The problem remaining, therefore, was that of freeing the prepn. of the other proteins. The addn. of Mn or Co salts, brought to pH 4, with the immediate addn-. of an excess of phosphate buffer of pH 9 cleared the soln. of all colored substances, with loss of 35-45% of activity. Electrophoretic analysis showed the presence of 2 constituents. Arginase was found in the slower of the 2 moving fractions. The spectrophotometric peak at 412 m[mu] before purification showed a considerable drop after Co treatment. Arginase apparently was a colorless enzyme with albumin properties. The following ions, in addn. to Co, were tested for purification purposes: Mn, Ni, Cd, Sn, Sr, Ba, Ca, Mg, and Pb. The first 4 were rated as good for clarification purposes ; only Mn, Ni, and Sr gave yields comparable with those from Co. No details of methods were given.