Chinese Journal of Physiology

Chinese Journal of Physiology, 1929, Vol, III, No, 7, pp. 7—28.

STUDIES ON DENATURATION OF PROTEINS VIL. EFFECT OF DENATURATION AND COAGULATION ON ACID- AND BASE-BINDING POWER OF PROTEINS

HSIEN WU sanp TUNG-TOU CHEN

(From the Department of Biochemistry, Peking Union Medical College, Peping)

Received for publication August 29, 1928

The purpose of the present study is to throw light on the nature of the process underlying denaturation of proteins by ascertaining whether denatured proteins combine with more or less acid or alkali than the natural proteins. An increase in acid- and base-binding power would point to a hydrolysis or some other kind of degradation, while a decrease would indicate a change in the opposite direction.

HISTORICAL

Chick and Martin (1, 2) found that “heat denaturation” of egg albumin in alkaline solution was accompanied by a decrease of alkalinity and in acid solution by a decrease of acidity. These investigators, however, heated the egg albumin in solutions of such reaction that not only denaturation but coagulation occurred. The change in reaction which they obsevered might not be due to denaturation but to coagulation. Working with cow’s hemoglobin Lewis (4) found no change of acid- or base-binding power as the result of “heat denaturation”. He did not state whether the hemoglobin was coagulated or not. Judging from the conditions of his experiment and our experience with this protein, we surmise that coagulation must have occurred. Our experiments with dog’s and sheep’s hemoglobin have failed to corroborate his