pH对几种来源异柠檬酸裂解酶活性的影响

发布时间：2018-07-05 01:23

本文选题：异柠檬酸裂解酶 + 缓冲液　；参考：《内蒙古农业大学》2017年硕士论文

【摘要】：本实验以三种细菌和四种植物中的异柠檬酸裂解酶作为材料,研究了该酶在不同pH值缓冲液条件下的活性,分析了氨基酸序列与酶活性大小的相关性。结果显示:大肠杆菌(Escherichia coli)、结核分枝杆菌(Mycobacterium tuberculosis)、铜绿假单胞菌(Pseudomonas aeruginosa)中异柠檬酸裂解酶的最适pH值分别为5.6、6、7,玉米(Zeamays)、大豆(Glycne max)、黄瓜(Cucumis sativus)、马铃薯(Solanum tuberosum)中异柠檬酸裂解酶的最适pH值分别为6、6.6、6.6、7.6。通过分析ICL氨基酸序列发现该酶的最适pH值与组成蛋白质中的某一类特殊氨基酸残基(中性条件下带正电/负电氨基酸,芳香族氨基酸和极性/非极性氨基酸)的个数或百分含量没有相关性,而在研究单个氨基酸残基时发现:在以上7个物种的ICL氨基酸序列中,组氨酸残基所占的百分含量分别为1.83%、2.33%、2.63%、2.09%、2.49%、2.42%、2.60%,且最适pH值相同的黄瓜和大豆中组氨酸残基所占的百分比相差很小。实验结果表明:不同物种中异柠檬酸裂解酶的最适pH值与组氨酸残基的含量有关,其随着组氨酸残基含量的增加而增大。
[Abstract]:In this experiment, isocitrate lyase from three bacteria and four plants were used as materials to study the activity of isocitrate lyase in different pH buffer solution, and the correlation between amino acid sequence and enzyme activity was analyzed. The results showed that the optimum pH values of isocitrate lyase in Mycobacterium tuberculosis), pseudomonas aeruginosa were 5. 6% and 6. 6%, respectively. The optimum pH values of isocitrate lyase in maize and soybean (Glycne max), cucumber) were 6 6. 6 and 6. 6 and 7. 6, respectively. The optimum pH values of isocitrate lyase in Escherichia coli), were 6. 6%, 6. 6%, 6. 6% and 6. 6%, respectively. The optimum pH values of isocitrate lyase in maize (Zeamays) and soybean (Glycne max), cucumber) were 6? By analyzing the amino acid sequence of ICL, it was found that the optimum pH value of the enzyme and a special amino acid residue (positive / negative amino acid) in the composition of the protein were positive / negative amino acids under neutral conditions. There was no correlation between the number or percentage of aromatic amino acids and polar / nonpolar amino acids, but in the study of single amino acid residues, it was found that in the ICL amino acid sequences of the seven species, The percentage of histidine residue was 1.83% and 2.33%, respectively. The percentage of histidine residue in cucumber with the same optimum pH value was slightly different from that in soybean, and the percentage of histidine residue in cucumber and soybean was 2.09 and 2.49 and 2.42 and 2.60 respectively. The results showed that the optimum pH value of isocitrate lyase in different species was related to the content of histidine residue, which increased with the increase of histidine residue content.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q55

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