Über Peptidasen im Hühnereiklar und in aus ihm gewonnenen Präparaten

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Abstract
The reaction mixture contained 1.25 cc. veronal acetate buffer in a total vol. of 12.5 cc; 0.36 g. gelatin, casein or peptone ultra concentrate; or 0.28 g. leucylglycine or 0.2 g. glycylglycine; manganous chloride, 0.001 M; cysteine hydrochloride, 0.004 M; amts. of the various chicken egg albumin preparations usually equivalent to 0.36 g. dry wt. (1/2 of this amt. for the acetone precipitated product, and 1/8 for the lysozyme prod-duct). The mixtures were sterile and were incubated from 20-120 hrs. at 40[degree]. The course of the cleavage was followed by determining the increase in the number of ml. of N/20 Na ethylate used in titrating the samples. In fresh sterile egg albumin solns., in sterile dry prepns., acetone precipitates, or glycerin extracts of acetone precipitates of egg albumin, poly- and dipeptidases were present, which were not further activated by Mn. The albumin preparations did not split d-leucylglycine even in the presence of cysteine and Mn. A crude avidin prep. from chicken egg albumin contained the same enzymes as the albumin, except that the dipeptidases were active only in the presence of Mn. Neither the egg albumin nor the lysozyme obtained from it contained proteases. The proteases present in commercial egg albumin were due to contamination with protease forming bacteria.

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