不同pH值下金属硫蛋白的电喷雾质谱研究

Study on the Metallothioneins at Different pH by Electrospray Ionization-Mass Spectrometry

考察不同 p H值下金属硫蛋白与锌 (Zn)的结合情况表明 ,p H值下降 ,总离子流强度增大 ,但低于 3以后 ,又急剧下降 ;同时 p H也决定了金属与硫蛋白的结合形态 ,在比较理想的电离的条件下发现 ,在 p H 3 .0时主要以脱金属硫蛋白的形式存在 ;在 p H4.0时金属硫蛋白结合了 4个 Zn。

The total ion intensities of the metallothioneins(MTs) increase from pH 7 to 3. The use of electrospray mass spectrometry render it possible to acquire molecular and chemical binding information of the metallothioneins at different pH condition. The result shows that pH is the primary factor to determine the zinc combind to metallothioneins. Metallothioneins are conbined with four zinc at pH 4.0 while none zinc is found to be conbined to the protein at pH 3.0.