[Study of hemoglobin structure by a turbidimetric method]

The initial velocity of coagulation of human oxyhemoglobin in tris-HCl buffer measured by turbidimetric method, pH 7.2 in the presence of phenylmercuryacetate made it possible to estimate the amount of moles of this reagent stechiometrically binding with hemoglobin without coagulation of the latter. At 15-30 degrees C this amount is 30-34 mole per hemoglobin-tetramer. At temperature increase from 30 to 42.5 degrees C the amount of the reagent necessary for protein coagulation sharply decreases. A model is proposed assuming that oxyhemoglobin coagulation proceeds only during binding of the reagent with specific protein sites.