Proton transfer in histidine hydrochloride induced by a dipolar aprotic solvent.
نویسندگان
چکیده
A 1H NMR study of histidine hydrochloride dissolved in water/dimethyl sulfoxide mixtures gives evidence that dimethyl sulfoxide is able to induce a proton transfer from the imidazolinium nitrogens (mainly N3) to the carboxylate group when its mole fraction becomes greater than 42%. The new tautomeric equilibrium AH2++- in equilibrium AH2+ is quantitatively studied as a function of the solvent composition. In pure dimethyl sulfoxide, this equilibrium is strongly biased toward the monocation AH2+, which represents 91% of the total histidine hydrochloride.
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ورودعنوان ژورنال:
- The Journal of biological chemistry
دوره 256 16 شماره
صفحات -
تاریخ انتشار 1981