Chinese Journal of Physiology

78 H. WU anp T, T, CHEN

solution coagulated at the isoelectric point. From table 1 it will be noted that the two were practically the same. We may conclude, therefore, that the albumin solution used was free from ovomucoid and that the liberation of non-protein chromogenic substances observed in the alkaline and acid solutions was real and not due to differential adsorption of that substance.

At the isoelectric point there is practically no liberation of nonprotein chromogenic substances. On either side of this point there is some liberation, much more on the alkaline than on the acid side. Since it has been shown that coagulation is not denaturation followed by flocculation but an entirely different process (8) and that heating of egg albumin at the isoelectric point probably causes coagulation without denaturation (4), we may conclude that coagulation of egg albumin is not, but denaturation is, accompanied by liberation of non- -protein chromogenic substances.

ry 1 —t | ; & a 0.15 i =r 3 aQ + inoue] aes “| ie {| si aml [ | bp —e = £ 9 | Qn ’ | 4 0.10 1 wy 2 See a — al ie See i oa ° | tea) \ A: | | = 0.0 II do | a a @ *ECSSEC CET HI | | °: 2 1.0 0.0 1.0 2.0 N NE Cc. 10 Hel Cc. To NaOH Fig. 2. Liberation of non-protein chromogenic substances on denaturation

and coagulation of sheep’s serum globulin,