RESUMO
At 20 degrees C, in a phosphate buffer, pH 5,8--8,0, methanol and aniline interactions with hemoglobin and cytochrome c were studied using the difference spectrophotometry method. The difference absorption spectra are characterized by following values of lambdamax and lambdamin (nm): I--MeOH--hemoglobin (405 and 420), II-MeOH--cytochrome c (405--406 and 419--422), III--aniline--cytochrome c (421--410 and 401--396). The values of lambdamax and lambdamin for system III are shifted in the region of shorter wavelengths from 421 to 410 nm and from 401 to 396 nm, respectively within the pH range of 5,8--7,95. From difference spectra for systems I, II, III the dissociation constants of complexes obtained, Ks were calculated. Log Ks is linearly dependent on pH. System I is characterized by two values of Ks at all pH. The Ks values were calculated in general form from the dependences obtained. The nature of the complexes is discussed.
