氨基酸与肾上腺素相互作用的伏安特性及理论研究
发布时间：2018-08-02 10:17
【摘要】： 氨基酸是构建生物机体的众多生物活性大分子之一,是构建细胞、修复组织的基础材料。肾上腺素是哺乳动物和人类的一种重要的儿茶酚胺类神经传递物质,它控制着神经系统进行一系列生物反应及神经化学过程。研究氨基酸分子与肾上腺素的相互作用,对于推动生命科学、药物化学、物理化学等学科的发展能起到一定的积极作用。本文用电化学方法研究了甘氨酸、丝氨酸、谷氨酸、天冬氨酸、苯丙氨酸五种氨基酸对肾上腺素电化学氧化的循环伏安曲线的影响,着重讨论了等电点前后天冬氨酸对肾上腺素电化学行为的影响,并辅助于量子化学方法对天冬氨酸与肾上腺素形成的氢键复合物进行了理论探讨。 利用循环伏安法研究了甘氨酸、丝氨酸、谷氨酸、天冬氨酸、苯丙氨酸在盐酸体系中对肾上腺素电子转移性质的影响,实验结果表明:盐酸溶液中,这几种氨基酸对肾上腺素具有一定的稳定作用,能在一定程度上抑制肾上腺素的氧化,从而改变了肾上腺素的循环伏安特征,结构不同的五种氨基酸抑制肾上腺素氧化的能力也有所不同,并且溶液离子强度对肾上腺素的电氧化行为也有影响,但并未影响不同结构的氨基酸抑制肾上腺素氧化能力的大小:甘氨酸＜丝氨酸＜谷氨酸＜天冬氨酸＜苯丙氨酸。此外还运用循环伏安法和交流阻抗着重研究了天冬氨酸对肾上腺素氧化行为的影响,实验发现,由于天冬氨酸在等电点之前主要以正离子的形式存在于水溶液中,对质子化的肾上腺素有排斥作用,在等电点时主要以中性的偶极离子形式存在,对质子化的肾上腺素排斥作用较小,而在等电点后虽然负离子的形式对带正电荷的肾上腺素有一定的吸引作用,但由于肾上腺素的质子化发生在其结构中的-NH_2上,形成-NH_3~+。-NH_3~+与天冬氨酸负离子中的-COO~-相互吸引容易形成氢键,但是却减少了肾上腺素酚羟基与天冬氨酸形成氢键的机会,从而减弱了对肾上腺素的保护能力。故在实验中所表现出来的即为等电点前肾上腺素与天冬氨酸的相互作用能力随pH值的增大而增大,到达等电点后这种增大变缓,所以在等电点后肾上腺素与天冬氨酸的相互作用能力比等电点时略微增加。 用量子化学方法优化了天冬氨酸能与肾上腺素能形成氢键复合物的几何构型,气相和液相中天冬氨酸能与肾上腺素形成1:1氢键复合物,氢键的形成对肾上腺素的羟基起到了保护作用,使其苯环上相邻的羟基(-OH)上的H难以脱去,降低了体系的能量,增加了肾上腺素的稳定性,在一定程度上抑制了肾上腺素的氧化,并且获得了结构参数和能量,解释了有关实验现象。
[Abstract]:Amino acid is one of the bioactive macromolecules in the construction of biological organism, and it is the basic material to construct cells and repair tissues. Epinephrine is an important catecholamine neurotransmitter in mammals and humans. It controls a series of biological reactions and neurochemical processes in the nervous system. The study of the interaction between amino acid molecules and epinephrine can play a positive role in promoting the development of life science, drug chemistry, physical chemistry and so on. The effects of five amino acids, glycine, serine, glutamic acid, aspartic acid and phenylalanine, on the cyclic voltammetry of epinephrine were studied by electrochemical method. The influence of aspartic acid on the electrochemical behavior of epinephrine before and after isoelectric point was discussed emphatically, and the hydrogen bond complex formed between aspartic acid and epinephrine was studied theoretically by quantum chemical method. The effects of glycine, serine, glutamate, aspartic acid and phenylalanine on the electron transfer properties of epinephrine in hydrochloric acid system were studied by cyclic voltammetry. These amino acids have a certain stabilizing effect on epinephrine, which can inhibit the oxidation of epinephrine to some extent, thus changing the cyclic voltammetry of epinephrine. The ability of five amino acids with different structures to inhibit the oxidation of epinephrine was also different, and the ionic strength of the solution had an effect on the electrooxidation of epinephrine. But it did not affect the ability of different amino acids to inhibit the oxidation of epinephrine: glycine < serine < glutamic acid < aspartic acid < phenylalanine. In addition, the effects of aspartic acid on the oxidation of epinephrine were studied by cyclic voltammetry and AC impedance. It was found that aspartic acid mainly existed in aqueous solution in the form of positive ions before isoelectric point. The protonation of epinephrine is repellent. At the isoelectric point, it mainly exists in the form of neutral dipole ion, but has little repellent effect on protonated epinephrine. But after isoelectric point, although the form of negative ion has a certain attraction to the positively charged epinephrine, but the protonation of epinephrine occurs in the structure of its structure, It is easy to form hydrogen bond between -NH3.-NH _ S _ 3~ and -COOO- in aspartic acid anion, but it reduces the chance of forming hydrogen bond between adrenophenol hydroxyl and aspartic acid, which weakens the protection of epinephrine. Therefore, the interaction ability of epinephrine and aspartic acid in the experiment increases with the increase of pH value and slows down after reaching the isoelectric point. So the interaction ability of epinephrine and aspartic acid after isoelectric point is slightly higher than that at isoelectric point. The geometric configuration of the hydrogen bond complex between aspartic acid and adrenergic was optimized by quantum chemical method, and the 1:1 hydrogen bond complex was formed between aspartic acid and epinephrine in gas phase and liquid phase. The formation of hydrogen bond protects the hydroxyl group of epinephrine, which makes it difficult to remove H from the adjacent hydroxyl group (-OH) on the benzene ring, which decreases the energy of the system and increases the stability of epinephrine. To some extent, the oxidation of epinephrine was inhibited, and the structural parameters and energy were obtained, which explained the experimental phenomena.
【学位授予单位】：曲阜师范大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R341
本文编号：2159111
[Abstract]:Amino acid is one of the bioactive macromolecules in the construction of biological organism, and it is the basic material to construct cells and repair tissues. Epinephrine is an important catecholamine neurotransmitter in mammals and humans. It controls a series of biological reactions and neurochemical processes in the nervous system. The study of the interaction between amino acid molecules and epinephrine can play a positive role in promoting the development of life science, drug chemistry, physical chemistry and so on. The effects of five amino acids, glycine, serine, glutamic acid, aspartic acid and phenylalanine, on the cyclic voltammetry of epinephrine were studied by electrochemical method. The influence of aspartic acid on the electrochemical behavior of epinephrine before and after isoelectric point was discussed emphatically, and the hydrogen bond complex formed between aspartic acid and epinephrine was studied theoretically by quantum chemical method. The effects of glycine, serine, glutamate, aspartic acid and phenylalanine on the electron transfer properties of epinephrine in hydrochloric acid system were studied by cyclic voltammetry. These amino acids have a certain stabilizing effect on epinephrine, which can inhibit the oxidation of epinephrine to some extent, thus changing the cyclic voltammetry of epinephrine. The ability of five amino acids with different structures to inhibit the oxidation of epinephrine was also different, and the ionic strength of the solution had an effect on the electrooxidation of epinephrine. But it did not affect the ability of different amino acids to inhibit the oxidation of epinephrine: glycine < serine < glutamic acid < aspartic acid < phenylalanine. In addition, the effects of aspartic acid on the oxidation of epinephrine were studied by cyclic voltammetry and AC impedance. It was found that aspartic acid mainly existed in aqueous solution in the form of positive ions before isoelectric point. The protonation of epinephrine is repellent. At the isoelectric point, it mainly exists in the form of neutral dipole ion, but has little repellent effect on protonated epinephrine. But after isoelectric point, although the form of negative ion has a certain attraction to the positively charged epinephrine, but the protonation of epinephrine occurs in the structure of its structure, It is easy to form hydrogen bond between -NH3.-NH _ S _ 3~ and -COOO- in aspartic acid anion, but it reduces the chance of forming hydrogen bond between adrenophenol hydroxyl and aspartic acid, which weakens the protection of epinephrine. Therefore, the interaction ability of epinephrine and aspartic acid in the experiment increases with the increase of pH value and slows down after reaching the isoelectric point. So the interaction ability of epinephrine and aspartic acid after isoelectric point is slightly higher than that at isoelectric point. The geometric configuration of the hydrogen bond complex between aspartic acid and adrenergic was optimized by quantum chemical method, and the 1:1 hydrogen bond complex was formed between aspartic acid and epinephrine in gas phase and liquid phase. The formation of hydrogen bond protects the hydroxyl group of epinephrine, which makes it difficult to remove H from the adjacent hydroxyl group (-OH) on the benzene ring, which decreases the energy of the system and increases the stability of epinephrine. To some extent, the oxidation of epinephrine was inhibited, and the structural parameters and energy were obtained, which explained the experimental phenomena.
【学位授予单位】：曲阜师范大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R341
【引证文献】
相关期刊论文 前1条
1 陈媛媛;王慧;郁章玉;;苯丙氨酸对肾上腺素电子转移性能的影响[J];菏泽学院学报;2008年05期
，本文编号：2159111
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