高密度脂蛋白体外氧化修饰动力学研究

在体外ＨＤＬ在Ｃｕ＾２＋诱导下可发生氧化修饰,为了探讨体外务浆高密度脂蛋白（ＨＤＬ）氧化修饰中几种产物的动力学改变,用Ｃｕ＾２＋与ＨＤＬ保温２￣２４ｈ,分别观察了ＨＤＬ氧化修饰过程中硫代巴比妥酸反应物质（ＴＢＡＲＳ）,脂氢过氧化物（ＬＯＯＨ）、共轭二烯（ＣＤ）及相对电泳迁移率（ＲＥＭ）等的变化。结果显示,ＬＯＯＨ和ＣＤ两个指标动力学变化相似,呈现延滞期,扩增期和下降期三个时相,而ＴＢＡＲＳ和ＲＥＭ     

巯基乙酸对蟾蜍血清转氨酶和钙含量的影响

以健康的中华蟾蜍为实验动物,研究皮肤染毒巯基乙酸(TGA)对血液天门冬氨酸氨基转氨酶(AST)、丙氨酸氨基转氨酶(ALT)和钙含量的影响,并对其作用机理进行初步探讨.试验结果表明,染毒巯基乙酸剂量对于血清AST、ALT和Ca含量影响效果明显.方差分析表明各试验处理组与对照组相比差异显著;染毒TGA的时间对于血清生化指标的影响呈现累积趋势,各试验处理组染毒后期与前期差异显著.表明巯基乙酸对于蟾蜍肝组织等器官具有明显的损伤作用,因此化工产品巯基乙酸对水体的污染不容忽视.     

氧化亚铁硫杆菌氧化亚硫酸盐的动力学研究

实验用Ms培养基,利用去除铁离子的氧化亚铁硫杆菌(Thiobacillus ferrooxidans)进行了细菌亚硫酸盐的生长代谢研究。实验结果表明氧化亚铁硫杆菌对亚硫酸根具有一定的氧化能力。用Origin 7.0对实验数据进行拟合处理,表明了氧化亚铁硫杆菌催化氧化亚硫酸盐的动力学方程符合Hill方程。氧化亚铁硫杆菌催化氧化亚硫酸盐是一个底物抑制的细胞反应,其KS值随pH值和底物浓度的改变而变化。pH值对反应有很大的影响,pH值越接近中性KS就越小,反应速率就越大。     

HcNPV半胱氨酸蛋白酶基因的核苷酸序列研究

ＨｃＮＰＶ半胱氨酸蛋白酶基因的核苷酸序列研究贡成良１小林淳宫岛成寿金伟１吴祥甫２＊（日本三重大学分子素材工学科,三重５１４,日本;１浙江农业大学蚕学系,杭州３１００２９;２中国科学院上海生物化学研究所,上海２０００３１）关键词美国白蛾;核型多角体病毒...     

土壤氧化还原酶催化动力学研究进展

土壤氧化还原酶是存在于土壤中的一种重要酶类,参与土壤中为数众多的重要生物化学反应,与土壤中有机物质的转化、腐殖质的形成以及土壤肥力变化密切相关.其催化反应的动力学研究常用来阐明其催化过程的特性、酶的本质属性及其对环境变化的响应等.研究土壤氧化还原酶动力学特征对探讨其来源、性质及影响因素,对进一步调控多种营养元素参与的反应过程有重要意义.文中概述了土壤氧化还原酶动力学研究的理论基础,综述了土壤氧化还原酶催化动力学研究的进展和影响因素,并对今后的研究提出了几点建议.     

电渗析法分离提纯N-乙酰-L-半胱氨酸研究

使用我校由辐射法制备的高性能离子交换膜ＨＦ—１及ＨＦ—２,采用电渗析技术对合成所得的Ｎ－乙酰－Ｌ－半胱氨酸进行了分离提纯,脱盐率＞１５％,损失率＜１５％,为工业化应用提供了依据。     

巯基乙酸对中华蟾蜍红细胞核异常的影响

试验以健康的中华蟾蜍为实验动物,研究注射巯基乙酸对红细胞核异常的影响.试验结果表明,在一定的范围内,巯基乙酸可引起蟾蜍微核细胞率和核异常细胞率遗传指标发生明显变化,随着巯基乙酸浓度的增加和作用时间的延长,蟾蜍红细胞微核和核异常率呈现先上升后下降的规律性变化.     

歼击飞行员飞行应激对同型半胱氨酸和皮质醇的影响

目的:探讨南部战区某旅歼击飞行员血清皮质醇(COR)和同型半胱氨酸(Hcy)联合检测的意义。方法:对歼击飞行员(A组)、地方健康体检人员(B组)、部队考学战士(C组)、空军地勤人员(C组)的血清COR、Hcy水平进行两两比较,通过Kruskal-Wallis统计学方法处理分析。结果:B组人员COR水平比A组、C组、D组人员低,差异有统计学意义(P<0.05);C组人员Hcy水平比A组、B组、D组人员高,差异有统计学意义(P<0.05)。结论:经常性的飞行训练可增强飞行员分泌激素的适应性,在航空保健工作中,COR联合Hcy监测及动态观察对保障飞行员的健康和飞行安全,提高部队战斗力具有一定的意义。     

冠心病患者血浆同型半胱氨酸和内皮功能的研究(英文)

目的:探讨冠心病患者血浆中同型半胱氨酸、内皮素、循环内皮细胞水平与冠状动脉粥样硬化性心脏病发生过程的关系。方法:对62例冠心病患者组和50例健康对照组分别采用高效液相色谱分析法和放射免疫分析法测定血浆中同型半胱氨酸水平和内皮素水平,同时测定血浆中循环内皮细胞的数量。结果:冠心病组同型半胱氨酸(21.27±5.73)μmol/L、内皮素(84.30±13.68)ng/L、循环内皮细胞(12.08±5.85)和cells/0.9μl明显高于对照组同型半胱氨酸(9.12±4.87)μmol/L、内皮素(47.65±12.71)ng/L、循环内皮细胞(2.35±1.02)cells/0.9μl,P均小于0.001。同型半胱氨酸与内皮素、循环内皮细胞呈正相关(r=0.601,P0.01;r=0.645,P0.01),且冠心病组血浆循环内皮细胞和内皮素呈正相关(r=0.850,P0.01)。结论:同型半胱氨酸及内皮素对冠状动脉粥样硬化性心脏病的发生发展有促进作用,对其检测有临床实用价值。     

弱氧化醋杆菌阿拉伯糖醇脱氢酶基因克隆及其在大肠杆菌中的表达

The partial genomic library of Acetobacter suboxydans was constructed using Yeast| E.coli shuttle plasmid YEp352 as vector.Two positive transformants,designated as DH5α(pAD91) and DH5α(pAD98),were obtained by screening the growth of transformants on the agar plate in which D|arabitol was used as the sole carbon source.The results of Southern blot and restriction endonuclease analysis showed that the two recombinants are identical.The insert is about 2.3kb.Arabitol dehydrogenase activity assay indic…     

TGA对蟾蜍血清生理指标的影响

本试验利用生化检测方法,以健康的中华蟾蜍为实验动物,研究注射巯基乙酸对血液生理指标的影响,并对其作用机理进行了初步探讨.试验结果表明,随染毒TGA剂量增加,蟾蜍血清总蛋白、葡萄糖含量下降,胆固醇、甘油三酯含量上升;随染毒TGA时间的延长,血清总蛋白、葡萄糖含量先下降后上升但均低于对照组,胆固醇、甘油三酯含量先上升后下降但均高于对照组.因此提示化工产品对生物的影响不容忽视.     

Biological Reduction of Ferric Iron by Iron- and Sulfur-oxidizing Bacteria

B-1625 FA_2β, one of the minor acidic actinomycin congeners produced by Streptomyces antibioticus No. B-1625, was produced selectively on the combined use of sarcosine and ferrous sulfate in a complex medium. The FA_2β was further separated into two components, MeOH- insoluble FA_{2β – 1} and MeOH-soluble FA_{2β – 2}, by methanol treatment. After repeating the MeOH treatment, the purified FA_{2β – 1} was examined as to its physicochemical properties, and subjected to amino acid analysis, and ¹³C-, ¹H-NMR and FAB mass spectral measurements. As a result, the structure of FA_{2β – 1} was deduced to be 2-amino-1-carboxyl-4,6-dimethyl-3-phenoxazone-9- carbonyl-threonyl-valyl-sarcosyl-sarcosyl-N-methylvaline. As much as 1 mg/ml of FA_{2β – 1} showed no antibacterial activity against Gram-negative or Gram-positive bacteria, although FA_{2β – 2} shows antibiotic activity.     

Effect of Thiolated Polymers to Textural and Mucoadhesive Properties of Vaginal Gel Formulations Prepared with Polycarbophil and Chitosan

The aim of this study was to design and evaluate of mucoadhesive gel formulations for the vaginal application of clomiphene citrate (CLM) for local treatment of human papilloma virus (HPV) infections. Chitosan (CHI) and polycarbophil (PC) were covalently modified using the thioglycolic acid and L-cysteine, respectively. The formation of thiol conjugates of chitosan (CHI-TG) and polycarbophil (PC-CYS) were confirmed by FT-IR analysis and PC-CYS and CHI-TG were found to have 148.42 ± 4.16 and 41.17 ± 2.34 μmol of thiol groups per gram of polymer, respectively. One percent CLM gels were prepared by combination of various concentrations of PC and CHI with thiolated conjugates of these polymers. Hardness, compressibility, elasticity, adhesiveness and cohesiveness of the gels were measured by Texture profile analysis and the vaginal mucoadhesion was investigated by mucoadhesion test. The increasing in the amount of the thiol conjugates was found to enhance the elasticity, cohesiveness, adhesiveness and mucoadhesion of the gel formulations but not their hardness and compressibility when compared to gels prepared using their respective parent formulations. Slower release rate of CLM from gels was achieved when the polymer concentrations were increased in the gel formulations. PC and its thiol conjugate were found to prolong the release of CLM longer than 70 h unlike gel formulations prepared using CHI and its thiol conjugate which were able to release CLM up to 12 h. Stability of CLM was preserved during the 3 month stability analysis under controlled room temperature and accelerated conditions.     

Implications of the role of reactive cystein in arginine kinase: reactivation kinetics of 5,5'-dithiobis-(2-nitrobenzoic acid)-modified arginine kinase reactivated by dithiothreitol

The reduction of 5,5'-dithiobis-(2-nitrobenzoic acid)-modified arginine kinase by dithiothreitol has been investigated using the kinetic theory of the substrate reaction during modification of enzyme activity. The results show that the modified arginine kinase can be fully reactivated by an excess concentration of dithiothreitol in a monophasic kinetic course. The presence of ATP or the transition-state analog markedly slows the apparent reactivation rate constant, while arginine shows no effect. The results of ultraviolet (UV) difference and intrinsic fluorescence spectra indicate that the substrate arginine-ADP-Mg2+ can induce conformational changes of the modified enzyme but adding NO3- cannot induce further changes that occur with the native enzyme. The reactive cysteines' location and role in the catalysis of arginine kinase are discussed. It is suggested that the cysteine may be located in the hinge region of the two domains of arginine kinase. The reactive cysteine of arginine kinase may play an important role not in the binding to the transition-state analog but in the conformational changes caused by the transition-state analog.