山西大学学报（自然科学版）
山西大學學報（自然科學版）
산서대학학보（자연과학판）
JOURNAL OF SHANXI UNIVERSITY
2005年
4期
383-387
,共5页
过氧化氢酶%DNA%直接电化学%电化学催化
過氧化氫酶%DNA%直接電化學%電化學催化
과양화경매%DNA%직접전화학%전화학최화
Catalase%DNA%Direct electrochemistry%Electrocatalysis
通过将单、双螺旋的小牛胸腺DNA膜修饰在热解石墨电极上,研究了过氧化氢酶的直接伏安和电催化性质.结果表明过氧化氢酶(Cat)-DNA膜上显示出一对很好的几乎可逆的循环伏安峰,在50 mmol·L,pH为7.0磷酸缓冲溶液中,扫描速度为0.1 V·s-1情况下,单、双螺旋DNA膜上,其式电位分别为-0.223 V和-0.209V,其还原和氧化电子传递速率常数值分别为ks,red=21.0 s-1;ks,ox=33.0 s-1和ks,Red=13.5 s-1;ks,ox=13.3 s-1.在pH为3.81～7.72的范围内,Fe(Ⅲ)/Fe(Ⅱ)电对的还原电位随pH呈线性变化,表明一电子的转移伴有一质子的耦合.另外从紫外可见吸收光谱可见,在中性pH条件下,过氧化氢酶在DNA膜中保持了原有的结构不变.此外,我们还研究得到在DNA膜中过氧化氢酶保持了对过氧化氢的催化活性,并提出了可能的催化机制.
通過將單、雙螺鏇的小牛胸腺DNA膜脩飾在熱解石墨電極上,研究瞭過氧化氫酶的直接伏安和電催化性質.結果錶明過氧化氫酶(Cat)-DNA膜上顯示齣一對很好的幾乎可逆的循環伏安峰,在50 mmol·L,pH為7.0燐痠緩遲溶液中,掃描速度為0.1 V·s-1情況下,單、雙螺鏇DNA膜上,其式電位分彆為-0.223 V和-0.209V,其還原和氧化電子傳遞速率常數值分彆為ks,red=21.0 s-1;ks,ox=33.0 s-1和ks,Red=13.5 s-1;ks,ox=13.3 s-1.在pH為3.81～7.72的範圍內,Fe(Ⅲ)/Fe(Ⅱ)電對的還原電位隨pH呈線性變化,錶明一電子的轉移伴有一質子的耦閤.另外從紫外可見吸收光譜可見,在中性pH條件下,過氧化氫酶在DNA膜中保持瞭原有的結構不變.此外,我們還研究得到在DNA膜中過氧化氫酶保持瞭對過氧化氫的催化活性,併提齣瞭可能的催化機製.
통과장단、쌍라선적소우흉선DNA막수식재열해석묵전겁상,연구료과양화경매적직접복안화전최화성질.결과표명과양화경매(Cat)-DNA막상현시출일대흔호적궤호가역적순배복안봉,재50 mmol·L,pH위7.0린산완충용액중,소묘속도위0.1 V·s-1정황하,단、쌍라선DNA막상,기식전위분별위-0.223 V화-0.209V,기환원화양화전자전체속솔상수치분별위ks,red=21.0 s-1;ks,ox=33.0 s-1화ks,Red=13.5 s-1;ks,ox=13.3 s-1.재pH위3.81～7.72적범위내,Fe(Ⅲ)/Fe(Ⅱ)전대적환원전위수pH정선성변화,표명일전자적전이반유일질자적우합.령외종자외가견흡수광보가견,재중성pH조건하,과양화경매재DNA막중보지료원유적결구불변.차외,아문환연구득도재DNA막중과양화경매보지료대과양화경적최화활성,병제출료가능적최화궤제.
The direct voltammetry and electrocatalytic properties of catalase (Cat) in single-stranded or doublestranded (ss-or ds-) calf thymus DNA films cast on pyrolytic graphite (PG) electrodes were investigated. CatDNA film electrodes showed a pair of well-defined and nearly reversible cyclic voltammetry peaks. The formal -0. 209 V with dsDNA and -0. 223 V with ssDNA, respectively. The electron transfer between catalase and PG electrodes was greatly facilitated in the DNA films. At a dsDNA/PG electrode,reduction and oxidation electrontransfer rate constant values of ks, red= 13.5 s-1 and ks ,ox= 13.3 s-1 were obtained. At the ssDNA/PG electrode,the values were ks, red = 21. 0 s-1 and ks, ox = 33. 0 s 1, respectively. UV-Vis absorption spectroscopy demonstrated that catalase retained a near native conformation in DNA films at medium pH. We further investigated the responding with pH,Scanrate and H2O2. Obtaining a series valued information.
