Abstract
The rate of proton exchange in the 2′-position of thiamine pyrophosphate was determined by following the corresponding signal intensity of the proton magnetic resonance spectrum in 2H2O. In acidic solution the exchange rate was found to be inversely proportional to the 2H+ concentration. Above p2H = 5 the exchange rate was too rapid for measurement. Because of the rapid spontaneous H exchange in ...
Abstract
The rate of proton exchange in the 2′-position of thiamine pyrophosphate was determined by following the corresponding signal intensity of the proton magnetic resonance spectrum in 2H2O. In acidic solution the exchange rate was found to be inversely proportional to the 2H+ concentration. Above p2H = 5 the exchange rate was too rapid for measurement. Because of the rapid spontaneous H exchange in the physiological pH range, participation of an enzyme in the formation of the 2′-carbanion, the first step in all enzymic reactions catalysed by thiamine pyrophosphate, can be considered to be unnecessary.