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用电化学方法研究了咖啡酸与DNA的相互作用,考察了扫速对咖啡酸与DNA相互作用的影响。实验表明,DNA存在使咖啡酸氧化峰的电位正移,咖啡酸的氧化峰峰电流减小,咖啡酸在320 nm吸收光谱的吸收峰降低,呈减色效应,且出现两个等电吸收点,说明咖啡酸与DNA的相互作用以嵌插作用为主。双链DNA(dsDNA)与咖啡酸的结合能力大于单链DNA(ssDNA),结合比为1∶1,结合常数β为2.32×106。 相似文献
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利用示差脉冲伏安法研究了烟酰胺(NA)与小牛胸腺DNA在pH 8.0条件下相互作用的电化学行为.双链DNA(dsDNA)或单链DNA(ssDNA)的存在导致NA的峰电流明显降低且峰电位负移,表明NA与DNA发生相互作用,生成了复合物,且其作用模式主要是静电模式,但NA与dsDNA的相互作用强于与ssDNA的相互作用,可用于识别dsDNA和ssDNA.通过dsDNA加入前后峰电流的变化,计算得出NA与dsDNA结合常数β=4.946×10(11),结合位点数m=3.此外,NA的峰电流Ip与DNA质量浓度在1~14mg/L的范围内呈线性关系,线性回归方程为Ip(10-5A)=-0.03451cDNA(mg/L)+1.7408,相关系数R为0.9998.该法具有良好的回收率和选择性,可用于样品中DNA的测定. 相似文献
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更生霉素-DNA反应的电化学研究 总被引:1,自引:0,他引:1
研究了更生霉素(Act-D)在活化浸蜡石墨电极上的电化学特性,发现在-0.19和-0.51V分别出现一个灵敏的氧化峰和还原峰,加入DNA使Act-D的峰电流明显降低,生成了非电活性络合物.采用电化学方法研究了Act-D与小牛胸腺DNA的结合平衡,根据不可逆电活性分子与DNA相互作用的电化学公式对实验数据进行非线性拟合,获得了Act-D的扩散系数、Act-D与DNA的结合常数和结合位点数等重要信息,发现Act-D与DNA的8个碱基对紧密结合,其侧链加强了结合程度. 相似文献
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不可逆电活性药物米托蒽醌与脱氧核糖核酸的相互作用 总被引:4,自引:0,他引:4
研究了抗癌新药米托蒽醌(MXT)的电化学行为及与脱氧核糖核酸(DNA)的相互作用,推导了适用于研究不可逆电活性分子与DNA相互作用的电化学公式,运用该公式可以简便、快速地测定靶向分子与DNA的结合常数和结合位点数。实验发现,MXT与小牛胸腺DNA的结合以蒽醌母核的嵌插作用为主,同时,烃氨基侧链与骨架磷酸基团之间的静电吸引对母核起稳定作用,使化合物易于嵌入DNA的平面结构。MXT与DNA相互作用引起的峰电流的变化可以用于分析测定DNA。 相似文献
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灯盏花素在多壁碳纳米管丝网印刷电极上的电化学行为及测定 总被引:1,自引:0,他引:1
采用循环伏安法(CV)和差分脉冲伏安法(DPV)研究了黄酮化合物灯盏花素在多壁碳纳米管丝网印刷电极(MWCNT/SPE)上的电化学行为及其测定方法.实验表明,在pH=5.0的HAc-NaAc缓冲溶液中,浓度为5.0×10-4 g/L的灯盏花素在MWC-NT/SPE电极上出现了一对准可逆氧化还原峰,峰电位Epa=0.21 V,Epc=-0.05 V,△E=0.26 V,峰电流ipa=1.18 μA,ipc=0.205 μA,ipa/ipc=5.76.灯盏花素的DPV氧化峰电流值与其浓度在1.2×10-4~2.8×10-3 g/L范围内呈线性关系(R=0.9990),检出限为1.2×10-4g/L.结果表明,该法测定灯盏花素便捷、可靠、较灵敏. 相似文献
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运用荧光光谱、吸收光谱研究了灯盏花素(Breviscapinun,BR)与牛血清白蛋白(Bovine Serum Albumin,BSA)的相互作用.BR对BSA的荧光光谱具有猝灭作用,其猝灭机制为静态-动态联合猝灭,BSA发射峰蓝移.Zn2+的存在使得BSA发射峰蓝移程度降低,猝灭常数、结合常数、结合位点数减小.在较大浓度Zn2+存在下,BR与BSA作用的相关系数增大,猝灭机制变为静态猝灭.从Zn2+与BR的竞争作用,热力学参数的变化、配位化合物的形成3个方面分析了影响BR与BSA作用的因素. 相似文献
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We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992. 相似文献
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David W. Murhammer 《Applied biochemistry and biotechnology》1991,31(3):283-292
The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed. 相似文献
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多环芳二酐型聚酯亚胺膜的透气性能李悦生,丁孟贤,徐纪平(浙江大学高分子科学与工程研究所,杭州,310027)(中国科学院长春应用化学研究所)关键词聚醚酰亚胺,聚酯酰亚胺,膜,透气性通常的聚酰亚胺加工性能较差,在芳环二酐的苯环间引入醚键等柔性基团后,其... 相似文献
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微量元素与疾病诊断治疗的研究现状及展望 总被引:8,自引:0,他引:8
对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述,包括:微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。 相似文献
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I. Luk
J. Pilka M. Kulí
kov P. Hrdlovi
《Journal of polymer science. Part A, Polymer chemistry》1977,15(7):1645-1653
Poly-p-ethylacrylophenone (PPEtAP) and poly-p-chloroacrylophenone (PPClAP) and their copolymers with styrene (PEtAP/S) and (PClAP/S) and with methyl methacrylate (PEtAP/MMA) and (PClAP/MMA) were prepared. Quantum yields of main-chain scissions at 366 nm at room temperature in benzene solution are of the same order as those of the unsubstituted polyacrylophenone and its copolymers. Substitution with chlorine and ethyl group in the para position compared to the unsubstituted polyacrylophenone and its copolymers leads to an increase of the lifetime for the n–π* excited triplet state, as is evident from the measured quenching constants of photolysis. The low-temperature emission spectra of the copolymers are similar to the spectra of the model compounds in a polymer film. For the homopolymer, however, the character of the emission spectrum changes considerably. 相似文献
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Concentrations and distributions of trace and minor elements in Chinese and Canadian coals and ashes
A total of 35 trace and minor elements including some of environmental significance were determined in each of a selection of 15 Chinese and 6 Canadian thermal coals and their ashes by using the SLOWPOKE-2 nuclear reactor facility of the University of Toronto. The concentrations and distributions of these constituents among the coals and their combustion products (viz. ash and volatile matter) are presented together with an interpretation of their significance in relation to the large scale combustion of these coals as thermal fuels in industrialized countries such as China and Canada. The detailed results showed wide variations in trace impurity concentrations (up to a factor of 100 and more) among the coals studied with few large differences between those of Chinese and Canadian origin except that the rare earths, Sc, Th, U, I, and Se were much higher in the former, other halogens, As and Na were lower. Values for elemental enrichment factors (EF) relative to normal crustal abundances indicated that only As(EF=13), Br(5.7), I(16), S(230), Sb(11) and Se(320) were appreciably enriched in coal. During static ashing at 750°C most of the halogens, S and Se were volatilized whereas most other inorganic constituents were highly retained and concentrated in the ash by factors of 6 to 11. 相似文献