Department of Biophysics, Molecular Biology and Bioinformatics, University College of Science, 92, Acharya Prafulla Chandra Road, Kolkata 700009, India.
Int J Biol Macromol. 2011 Jan 1;48(1):202-9. doi: 10.1016/j.ijbiomac.2010.11.003. Epub 2010 Nov 16.
We studied structural modifications of metmyoglobin (Mb) after short-term (6 days) and long-term (30 days) glycation by fructose (fructation). Fructation caused gradual changes in the structure of the protein with respect to increased absorbance at 280 nm, enhanced fluorescence emission (with excitation at 285 nm), increased surface accessible tryptophan residues and reduced α-helix content and change in tertiary structure. However, long-term fructation changed Mb to oxymyoglobin (MbO2), as demonstrated by different spectroscopic (absorption, fluorescence, circular dichroic and electron paramagnetic resonance) studies and trifluoperazine-induced oxygen release experiment. Fructation appeared to modify Arg139 to arg-pyrimidine, which exhibited antioxidative activity and might be involved in the conversion of met (Fe3+) to oxy (Fe2+) form of myoglobin.
我们研究了短期（6 天）和长期（30 天）果糖糖化（fructation）后肌红蛋白（Mb）的结构修饰。糖化导致蛋白质结构逐渐发生变化，表现在 280nm 处吸光度增加、荧光发射增强（激发波长 285nm）、表面可及色氨酸残基增加、α-螺旋含量降低以及三级结构改变。然而，长期的糖化将 Mb 转化为氧合肌红蛋白（MbO2），这可以通过不同的光谱（吸收、荧光、圆二色性和电子顺磁共振）研究和三氟拉嗪诱导的氧释放实验来证明。糖化似乎将 Arg139 修饰为 Arg-嘧啶，其表现出抗氧化活性，可能参与将肌红蛋白的 Met（Fe3+）形式转化为氧合（Fe2+）形式。
