Analysis of proteins

Abstract

Caseinogen treated with 1% NaOH at 37[degree] for 24 hr. and then acidified suffers loss of its P and amide groups; the product, containing 55% of the original N, is called depocasein. It resembles a meta-protein in solubility in 0.1N acid and alkali, but is precipitated by higher conc. of acid. Its amino-acids, in general those of caseinogen, show a few marked differences, tyrosine being 1% higher, methionine 0.8% lower and lysine and proline also lower. The most striking difference is in glutamic acid which is 17%; lower.