【摘要】： 氨基酸是構(gòu)建生物機(jī)體的眾多生物活性大分子之一,是構(gòu)建細(xì)胞、修復(fù)組織的基礎(chǔ)材料。腎上腺素是哺乳動(dòng)物和人類的一種重要的兒茶酚胺類神經(jīng)傳遞物質(zhì),它控制著神經(jīng)系統(tǒng)進(jìn)行一系列生物反應(yīng)及神經(jīng)化學(xué)過程。研究氨基酸分子與腎上腺素的相互作用,對(duì)于推動(dòng)生命科學(xué)、藥物化學(xué)、物理化學(xué)等學(xué)科的發(fā)展能起到一定的積極作用。本文用電化學(xué)方法研究了甘氨酸、絲氨酸、谷氨酸、天冬氨酸、苯丙氨酸五種氨基酸對(duì)腎上腺素電化學(xué)氧化的循環(huán)伏安曲線的影響,著重討論了等電點(diǎn)前后天冬氨酸對(duì)腎上腺素電化學(xué)行為的影響,并輔助于量子化學(xué)方法對(duì)天冬氨酸與腎上腺素形成的氫鍵復(fù)合物進(jìn)行了理論探討。 利用循環(huán)伏安法研究了甘氨酸、絲氨酸、谷氨酸、天冬氨酸、苯丙氨酸在鹽酸體系中對(duì)腎上腺素電子轉(zhuǎn)移性質(zhì)的影響,實(shí)驗(yàn)結(jié)果表明:鹽酸溶液中,這幾種氨基酸對(duì)腎上腺素具有一定的穩(wěn)定作用,能在一定程度上抑制腎上腺素的氧化,從而改變了腎上腺素的循環(huán)伏安特征,結(jié)構(gòu)不同的五種氨基酸抑制腎上腺素氧化的能力也有所不同,并且溶液離子強(qiáng)度對(duì)腎上腺素的電氧化行為也有影響,但并未影響不同結(jié)構(gòu)的氨基酸抑制腎上腺素氧化能力的大小:甘氨酸＜絲氨酸＜谷氨酸＜天冬氨酸＜苯丙氨酸。此外還運(yùn)用循環(huán)伏安法和交流阻抗著重研究了天冬氨酸對(duì)腎上腺素氧化行為的影響,實(shí)驗(yàn)發(fā)現(xiàn),由于天冬氨酸在等電點(diǎn)之前主要以正離子的形式存在于水溶液中,對(duì)質(zhì)子化的腎上腺素有排斥作用,在等電點(diǎn)時(shí)主要以中性的偶極離子形式存在,對(duì)質(zhì)子化的腎上腺素排斥作用較小,而在等電點(diǎn)后雖然負(fù)離子的形式對(duì)帶正電荷的腎上腺素有一定的吸引作用,但由于腎上腺素的質(zhì)子化發(fā)生在其結(jié)構(gòu)中的-NH_2上,形成-NH_3~+。-NH_3~+與天冬氨酸負(fù)離子中的-COO~-相互吸引容易形成氫鍵,但是卻減少了腎上腺素酚羥基與天冬氨酸形成氫鍵的機(jī)會(huì),從而減弱了對(duì)腎上腺素的保護(hù)能力。故在實(shí)驗(yàn)中所表現(xiàn)出來的即為等電點(diǎn)前腎上腺素與天冬氨酸的相互作用能力隨pH值的增大而增大,到達(dá)等電點(diǎn)后這種增大變緩,所以在等電點(diǎn)后腎上腺素與天冬氨酸的相互作用能力比等電點(diǎn)時(shí)略微增加。 用量子化學(xué)方法優(yōu)化了天冬氨酸能與腎上腺素能形成氫鍵復(fù)合物的幾何構(gòu)型,氣相和液相中天冬氨酸能與腎上腺素形成1:1氫鍵復(fù)合物,氫鍵的形成對(duì)腎上腺素的羥基起到了保護(hù)作用,使其苯環(huán)上相鄰的羥基(-OH)上的H難以脫去,降低了體系的能量,增加了腎上腺素的穩(wěn)定性,在一定程度上抑制了腎上腺素的氧化,并且獲得了結(jié)構(gòu)參數(shù)和能量,解釋了有關(guān)實(shí)驗(yàn)現(xiàn)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.
【學(xué)位授予單位】：曲阜師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2008
【分類號(hào)】：R341

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳媛媛;王慧;郁章玉;;苯丙氨酸對(duì)腎上腺素電子轉(zhuǎn)移性能的影響[J];菏澤學(xué)院學(xué)報(bào);2008年05期

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本文編號(hào)：2159111