细胞色素P450s代谢手性化合物研究进展

综述了细胞色素P450s（CYP450s）对手性化合物代谢的对映体选择性差异,探讨了CYP450s酶工程研究的进展。在环境科学方面,研究CYP450s代谢环境中手性污染物的选择性可为正确评价手性污染物及其产物的毒理作用并为环境中手性污染物的生物修复提供依据。     

ASA法测定细胞色素P450 2D6等位基因CYP2D6*6

细胞色素Ｐ４５０ ２Ｄ６９ＣＹＰ２Ｄ＾０基因２０６４Ｇ→Ａ突变,造成表达产物２１２位上谷氨酸变成甘氨酸,从而引起酶分子失活,被称为ＣＹ２Ｄ６＾＊６。利用等位基因特异扩增法,建立了ＡＳＡ－ＰＣＲ测定了ＣＹＰ２Ｄ６＾＊６的方法,经３９６例测定,说明本法快捷,准确,测定结果显示ＣＹＰ２Ｄ６＾＊６与ＣＹＰ２Ｄ６Ｔ共存,如何只为准确预测ＣＹＰ２Ｄ６酶活性,对ＣＹＰ２Ｄ６＾＊６进行测定并无意义。     

穿心莲内酯磺化物的工业生产

探讨穿心莲内酯磺化物工业化生产中的合适途径.穿心莲内酯+无水乙醇/浓硫酸→磺化72h+50%氢氧化钠液→调PH至7左右十95%乙醇→醇沉后静置2h→滤过得滤液→回收乙醇+注射用水→水沉后冷藏24h→滤过得滤液为穿心莲内酯磺化液→浓缩得稠膏后真空干燥(80℃)→得穿心莲内酯磺化物粉末.以上方法可有效将穿心莲内酯磺化形成磺酸盐,并获得满意的得率.此方法能适应工业化生产所需要的条件,为工业化大生产提供了一套简便易行的磺化工艺.     

羊踟蹰木藜芦烷类成分对细胞色素P450酶作用的虚拟研究

采用Discovery Studio 2.5软件的CDOCKER和LibDock模块进行分子对接,对羊踟蹰木藜芦烷类成分与细胞色素P450酶几种亚型作用机制进行虚拟研究。以已知的和羊踟蹰木藜芦烷类成分作为配体,细胞色素P450酶的4种亚型CYP3A4、CYP2C9、CYP2E1和CYP1A2作为受体进行对接,并将对接结果进行打分,评判配体与受体的结合模式和亲和力,揭示其可能的作用机制。结果显示CYP2E1、CYP1A2为羊踟蹰木藜芦烷类成分的主要作用靶点。     

兑水穿心莲内酯二琥珀酸半酯的合成工艺改进与关键工艺控制点

以穿心莲内酯、无水吡啶、琥珀酸酐、无水亚硫酸钠,在真空条件下,加热回流反应生成炎琥宁（脱水穿心莲内酯二琥珀酸半酯钾钠盐）的重要中间体脱水穿心莲内酯二琥珀酸半酯,在洗涤时使用酸性水溶液,总收率89．7％,含量91．3％,并对生产中关键控制点加以阐述。操作工序简便,生产成本大大降低,收率高。     

细胞色素P450BM3进化酶3D结构模建与分析

通过动力学参数测定、同源序列比较以及三维结构的模建，对三个能够羟基化吲哚生成靛蓝的高活力P450BM3进化酶E435T，D168H，D168NA225VK440N所导致的酶分子结构变化和可能的活力提高机制进行了初步分析。同源序列比较表明P450BM3晶体蛋白的氨基酸序列与同源的能够羟基化吲哚生成靛蓝的动物P450等同率只有13％～16％，并且这些突变位点均在同源的P450中没有发现。三维结构模建表明进化酶E435T高活力可能是该突变破坏了E435侧链羧基和K434赖氨酸侧链胍基之间强的氢键相互作用，使K434胍基这个带正电荷基团侧链的柔韧性增加：而进化酶D168H高活力可能是通过影响P450BM3空间结构来影响酶催化活性的改变。     

脱水穿心莲内酯二琥珀酸半酯的合成工艺改进与关键工艺控制点

以穿心莲内酯、无水吡啶、琥珀酸酐、无水亚硫酸钠,在真空条件下,加热回流反应生成炎琥宁(脱水穿心莲内酯二琥珀酸半酯钾钠盐)的重要中间体脱水穿心莲内酯二琥珀酸半酯,在洗涤时使用酸性水溶液,总收率89.7%,含量91.3%,并对生产中关键控制点加以阐述。操作工序简便,生产成本大大降低,收率高。     

牛支原体广西分离株P48的原核表达及蛋白纯化研究

为获得牛支原体P48蛋白,以提供免疫学诊断产品及疫苗开发原材料,研究运用PCR方法扩增牛支原体广西分离株的脂蛋白P48的编码基因,构建pET32a-P48重组质粒,导入BL21感受态细胞,在诱导剂异丙基硫代半乳糖苷(IPTG)的诱导作用下获得P48重组蛋白并进行纯化,然后以纯化蛋白免疫小鼠,借助间接ELISA测定血清抗...     

不同栽植密度对色素万寿菊种子产量的影响

文章试验采用4种不同株行距定植密度,进行色素万寿菊种子生产,试验结果表明：色素万寿菊种子生产的最佳栽植密度应为50cm×33cm。     

碘酸钾和碘化钾对大鼠肝脏SIRT1 mRNA表达的影响

目的:观察不同剂量的碘酸钾和碘化钾对大鼠肝脏SIRT1基因表达的影响。方法:根据喂养碘剂和剂量不同将Wistar大鼠随机分为8组,即:适碘组(KI、KIO3),10倍高碘组(10KI、10KIO3)、50倍高碘组(50KI、50KIO3),100倍高碘组(100KI、100KIO3)。喂养半年后,利用实时荧光定量PCR(Real-time PCR)分析大鼠肝脏SIRT1基因表达水平。结果:适碘组中,SIRT1在KI组中的mRNA表达量高于KIO3组,P<0.05;10倍剂量组中,SIRT1在10KI组中的基因表达水平明显高于10KIO3,P<0.01;50倍和100倍剂量组中,SIRT1的基因表达量在两种不同碘剂组中没有统计学差异,P>0.05;不论摄入何种碘剂,SIRT1在高剂量碘组中的基因表达量均高于适碘组。结论:高剂量的碘化剂和碘酸钾均可上调大鼠肝脏SIRT1基因表达量,肝脏SIRT1基因的表达上调可能是机体改善高碘致高脂血症的一种重要的分子机制。     

我国P2P网络借贷模式的发展现状及风险揭示研究

P2P 网络借贷是互联网金融创新的重要组成部分,对推动我国金融改革有重要意义。文章介绍了P2P网络借贷的发展脉络和发展现状,总结归纳了我国P2P 网络借贷的主要运作模式,分析了P2P 平台的资金来源与投向结构,揭示了我国发展P2P 网络借贷所面临的流动性风险、信用风险、操作风险以及政策和法律风险。     

Effect of Resveratrol and Nicotine on PON1 Gene Expression: In Vitro Study

Dietary and lifestyle factors have been shown to have a profound effect on paraoxonase-1 (PON1) activity. Cigarette smoke has been shown to inhibit its mass and activity where as resveratrol has been shown to enhance it. We exposed hepatoma derived cell line (HepG2) to resveratrol and nicotine in varying doses and measured PON1 enzymatic activity and PON1 gene expression. In addition, total protein content of HepG2 cells was also measured. Resveratrol in a dose of 15 μmol/l or above significantly increased the PON1 enzyme activity (p > 0.001) where as nicotine in a dose of 1 μmol/l or higher significantly reduced it (p < 0.05). The resveratrol in this dose also enhanced the PON1 gene expression whereas nicotine decreased it as compared to controls. However, the protein conent of cells was not changed suggesting that they were not cytotoxic in the doses used. Till date the antioxidant vitamins have shown disappointing results against LDL oxidation and cardiovascular protection. However, the effect of resveratrol on PON1 gene expression and activity was significant, suggesting increase in PON1 activity and enhanced gene expression may be its alternative mechanism for offering protection against cardiovascular disease and may be an potential pharmacological agent which can be used for this.     

Expression of antimicrobial peptide Cecropin P1 in Saccharomyces cerevisiae and its antibacterial and antiviral activity in vitro

BackgroundCecropin P1, acting as an antimicrobial, has a broad-spectrum antibacterial activity with some antiviral and antifungal properties. It is a promising natural alternative to antibiotics which is originally isolated from the pig intestinal parasitic nematode Ascaris suum. Many studies have shown that Cecropin P1 is helpful for the prevention or treatment of clinical diseases. Therefore, it is very necessary to establish a safe, nontoxic, and efficient expression method of Cecropin P1.ResultsThe results indicated that the recombinant protein was about 5.5 kDa showed by Tricine–SDS–PAGE and Western blot. And Cecropin P1 was efficiently secreted and expressed after 12 h of induction, with an increasing yield over the course of the induction. Its maximum concentration was 7.83 mg/L after concentration and purification. In addition, in vitro experiments demonstrated that Cecropin P1 not only exerted a strong inhibitory effect on Escherichia coli, Salmonella sp., Shigella sp., and Pasteurella sp., but also displayed an antiviral activity against PRRSV NADC30-Like strain.ConclusionsCollectively, the strategy of expressing Cecropin P1 in Saccharomyces cerevisiae is harmless, efficient, and safe for cells. In addition, the expressed Cecropin P1 has antiviral and antibacterial properties concurrently.How to cite: Jiang R, Zhang P, Wu X, et al., Expression of antimicrobial peptide Cecropin P1 in Saccharomyces cerevisiae and its antibacterial and antiviral activity in vitro. Electron J Biotechnol 2021;50. https://doi.org/10.1016/j.ejbt.2020.12.006     

Effect of vitamin A supplementation on hematopoiesis in children with anemia

Fifty children (1–4 years age) presenting with microcytic hypochromic anemia (hemoglobin less than 10g/dl) were studied in two groups of 25 each. Group I was supplemented with iron (ferrous sulphate 6 mg/kg/d) while group II in addition to iron was also supplemented with vitamin A (5000 IU/d). Hemoglobin concentration was found to be significantly increased after 4 weeks of iron supplementation. Rise in hemoglobin was comparatively more in-group II, as compared to group I, after 8 and 12 weeks. Serum iron was significantly higher after 4 weeks in both the groups. Packed cell volume (PCV) and retinol levels increased significantly in-group II only. The data suggests that supplementation of vitamin A improves hematopoiesis.     

参与并购活动企业的创新激励——基于上市企业并购案例的实证研究

上市企业的并购活动与它的创新产出有着密切的关系,企业的创新产出同时也受到企业财务状况的影响。通过研究并购企业与目标企业的创新产出,验证并购活动与创新激励的因果关系,得到的结果显示:并购活动会激发产业协同效应,并购企业在宣告日间能够获得正的累计超额收益。因此,并购活动是提升企业创新能力的重要途径。     

Amelioration of Combination of Paclitaxel and Di Allyl Sulfide on the Alterations of Bcl2, P53 and Apoptosis Changes Against 7,12 Di Methyl Benz (A) Anthracene Induced Skin Cancer in Experimental Animals

The purpose of this study was to investigate the Bcl2, P⁵³ and apoptosis changes against skin cancer in experimental animals. Skin cancer is the most common form of human cancer. It is estimated that over 1 million new cases occur annually. The annual rates of all forms of skin cancer are increasing each year, representing a growing public concern. It has also been estimated that nearly half of all Americans who live to age 65 are likely to develop skin cancer at least once. Skin cancer was induced in rats by Di Methyl Benz (a) Anthracene at the dosage of DMBA (5 µg) per animal, three times a week for 28 weeks after conformation of skin cancer treated with Paclitaxel and Di allyl sulfide for 30 days. The levels of Bcl2 gene expression were significantly decreased and P⁵³gene expression were markedly increased in Paclitaxel and Di allyl sulfide treated animals when compared with cancer bearing animals. The treatment with combination of Paclitaxel and Di allyl sulfide effectively reduced Bcl2 protein expression and also increased P⁵³gene expression. Moreover, the levels of Bcl2 and P⁵³ a good indicators of restoring the skin architecture, were also reversed in skin damage subjects after treatment with the herbal compounds preparation. So, from the obtained results it is concluded that a combination of Paclitaxel and Di allyl sulfide is capable of restoring the skin architecture and can also increase the apoptosis activities in skin cancer rats.     

Effect ofCrataeva nurvala bark decoction on enzymatic changes in liver of normal and stone forming rats

The influence of Crataeva nurvala bark decoction was studied in calcium oxalate stone forming rats, in relation to oxalate metabolism in liver. The activities of the major oxalate synthesizing enzymes in liver namely, glycollate oxidase (GAO) and lactate dehydrogenase (LDH) were significantly increased in the calculogenic group. Bark decoction treatment lowered the liver GAO activity considerably. Transport ATPases (Na⁺, K⁺ and Ca²⁺-ATPases) and alkaline phosphatase were enhanced in rats fed calculi producing diet, while the activities of acid phosphatase, inorganic pyrophosphatase and aminotransferases were slightly reduced. Bark decoction administration produced a marginal decrease in Na⁺, K⁺-ATPase and increase in aspartate aminotransferase activities, without significantly altering other enzyme activities. The decrease in liver GAO activity seen during bark decoction treatment, with concomitant decrease in kidney oxalate level, may prove beneficial as a prophylactic measure in preventing stone recurrence.     

Effects of short-term hormone replacement on atherogenic indices in Indian postmenopausal women

Indian ethnicity by itself is a strong risk factor for development of CAD in Indian postmenopausal women due to lower HDL levels as compared to Whites and women of oriental origin. We evaluated and compared the short-term effects of menopause, estrogen replacement therapy and combined estrogen and progestin replacement therapy on various atherogenic indices. 40 postmenopausal women, both surgical and natural (20 each) were selected. 10 surgical postmenopausal women were given 0.625 mg conjugated estrogens daily for 6 months and 10 natural postmenopausal women were given 0.625 mg conjugated estrogen with 2.5 mg medroxyprogesterone acetate daily. 20 women were included in the control group and given placebo. Fasting venous blood samples were analyzed for extended lipid profile and calculated atherogenic indices before starting the therapy and after 1,3 and 6 months. LDL and Apolipoprotein B increased (p<0.05) and those of Apolipoprotein A1 and HDL decreased in the control groups. In both the study groups levels of serum cholesterol and LDL decreased (p<0.05) and those of HDL and Apolipoprotein A1 increased (p<0.01). LDL/HDL, Apo B/ApoA1, Total Cholesterol/HDL decreased significantly (p<0.05) in both the study groups compared to the control groups. The effect of estrogen alone was more significant as compared to combination therapy. Log Triglycerides (TG)/HDL ratio showed a decrease in women on estrogen alone but the difference was not significant. Our study confirms that short term HRT has a favorable effect on atherogenic indices in Indian postmenopausal women.     

Effect of pH on spectral characteristics of P5C-ninhydrin derivative: Application in the assay of ornithine amino transferase activity from tissue lysate

Currently available method(s) for assaying pyrroline-5-carboxylate (P5C), an important intermediate metabolite of ornithine, proline and glutamate metabolic pathways, are cumbersome or not sensitive enough for microanalysis. The present study involving the synthesis of P5C followed by purity check, molecular mass (amu =113.1) determination by mass spectrometry and spectral characterization of P5C-ninhydrin derivative (λ max: 510 nm) confirmed the authenticity of the preparation. Studies on the effect of pH on spectral characteristics of P5C ninhydrin derivative demonstrated a significant change with respect to λ max (620 nm) and several ∼ 12 fold increase in molar extinction coefficient (ε: 1.96 × 10⁵) in alkaline conditions (pH:7.0–8.0) as compared to the reported Molar ε of 1.65 × 10⁴ at max λ 510 nm in ethanolic solution. The modified method, with the improved sensitivity, is adopted for the assay of ornithine amino transferase activity in WBC’s/platelets lysate(s) from human blood.