Chauvet-Monges A M, Monti J P, Crevat A, Vincent E J
Biochimie. 1979;61(11-12):1301-8.
The action of magnesium ion on the exchange rate of the proton in C2 of thiamine and thiamine diphosphate is studied at different values of pD. Above pD 5 the ion Mg2+ increases this exchange rate. The phenomenon is markedly enhanced for TDP rather than thiamine and increases with pD. Below pD 5 magnesium decreases the exchange rate. This decrease is greater for TDP than for thiamine. The maximum effect is reached at a magnesium concentration of 0.5/1 for thiamine and of 1/1 for TDP. T1 measurements are made for different pH values with and without magnesium ion. Results seem to prove that an increase in pD values from 3.9 to 5.9 leads to an accentuation of the molecules "folded" form. Nevertheless for a given pD value the TDP-Mg complex seems to have a more "folded" form than TDP.
研究了在不同pD值下镁离子对硫胺素和硫胺素二磷酸中C2位质子交换速率的影响。在pD大于5时，Mg2+离子会提高这种交换速率。对于硫胺素二磷酸（TDP），这种现象比硫胺素更为明显，并且随pD增加而增强。在pD小于5时，镁会降低交换速率。对于TDP，这种降低比硫胺素更大。对于硫胺素，在镁浓度为0.5/1时达到最大效果，对于TDP，在镁浓度为1/1时达到最大效果。在有和没有镁离子的情况下，针对不同pH值进行了T1测量。结果似乎证明，pD值从3.9增加到5.9会导致分子“折叠”形式加剧。然而，对于给定的pD值，TDP - Mg复合物似乎比TDP具有更“折叠”的形式。
