离子对人血清白蛋白影响的1H NMR研究

人血清白蛋白（HSA）上有很多的结合位点，对药物及内源性物质的运输有很重要的作用.由于HSA分子量大且结构复杂，核磁共振（NMR）谱图信号重叠严重，因此使用常规的NMR技术很难获得天然丰度HSA上结合位点的信息.我们通过新的谱编辑技术，将横向弛豫加权（T₂W）与RD-WaterLOGSY技术相结合（即T₂W-RD-WaterLOGSY），观察到了天然丰度HSA表面的一些明显的特征信号，且这些信号的分辨率较高；通过pH滴定和2D ¹H-¹H TOCSY实验，我们对观察到的信号做了初步指认，发现部分信号来自于HSA表面的组氨酸；然后，我们通过这些特征信号研究了金属离子与HSA之间的相互作用.结果表明该技术可用于简化天然丰度HSA的谱线，在不对HSA进行突变的情况下，能反映了Zn²⁺与HSA的强结合作用以及结合位点等信息.

Effects of Metal Ions on Human Serum Albumin Studied by Radiation Damping Water-Ligand Observed via Gradient Spectroscopy

Human serum albumin (HSA) contains many metabolite binding sites. It has been widely studied for its functions in drug transportation. Nuclear magnetic resonance (NMR) is a frequently used tool to study HSA. However, due to its high molecular weight, the NMR spectra of HSA acquired with the conventional methods are often crowded, making spectral assignment and data interpretation difficult. In this study, a new method, which combined radiation damping water-ligand observed via gradient spectroscopy (RD-WaterLOGSY) with transverse relaxation weighted (T2W) techniques, was proposed to simplify the NMR spectra of HSA. With the T2W-RD-WaterLOGSY technique, the effect of pH on HSA was studied, as well as the interactions between HSA and Zn2+. The results showed that the relative changes in chemical shift could be used as a probe to analyze the pH changes in HSA solution and the interactions between HSA and Zn2+.