Chinese Journal of Physiology

bo a

H. WU awnp T. T. CHEN

| | 0.6|———|- 7 t ; tS { 4 Si irae ° Pe Gs | = mie) qs CLI 2 o2 hcl 9a i a : Sj }- [|= a ! Ss Ae 0 | He t !

2.0 1.6 8 1.G

cc-Mw01 added:—_-—>Co wae added

Fig. 11, Change in acid-binding power of oxyhemoglobin on denaturation and coagulation.

protein is in. solution. Lewis made no mention of any difficulty encountered in bringing the coagulum into solution. We thought that if the coagulation occurred in the absence of any electrolyte the coagulum might be so fine and would redissolve in very dilute acids and alkales. Accordingly we dialyzed some crystalline dog’s oxyhemoglobin until free from salt, but the coagulum prepared from this was also insoluble. Of course there is the possibility that the stock hemoglobin solution which. Lewis used was so acid or alkaline that no coagulation occurred. in his experiment. In that case, it is probable that he was experimenting with hemoglobin which was already denatured.

DISCUSSION

That the solutions of the denatured protein are less acid in acid solution and less alkaline in alkaline solution than those of the corresponding natural protein can be interpreted as an increase of acid- and base-binding power of the protein on denaturation. The opposite phenomenon observed in coagulation, is, however, open to several interpretations. (A) The coagulated protein may have fewer acid- and base-binding groups due to some change in the protein molecule. (B) The coagulated protein, being less dispersed than the natural or flocculated protein, may require longer time to complete the combination

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