正交实验优化RGD-蛛丝蛋白基因工程菌高密度发酵条件

通过正交实验对RGD-蛛丝蛋白基因工程菌高密度发酵条件进行优化.选择pH、温度、诱导剂、前体物甘氨酸/丙氨酸4因素,分别在3个水平上进行考察.当菌体密度OD600 nm为35左右时,添加IPTG诱导5 h,确定了发酵诱导条件为前体物甘氨酸/丙氨酸质量浓度为0.5%,诱导剂IPTG浓度为0.4 mmol/L,pH为7.0,温度为37℃.工程菌密度OD600 nm 可达到53.1,目的蛋白比例可达到24.3%,每L发酵液菌体经纯化可得到410 mg的目的蛋白.     

利用RT-PCR技术鉴定人ZP3嵌合肽基因在昆虫细胞中的表达

目的：探讨在转录水平上对人卵透明带蛋白3(hZP3)嵌合肽在昆虫细胞中的表达鉴定．方法：用含目的基因的重组病毒感染昆虫细胞，用LiCl法提取RNA，以其为模板，利用一步法RT-PCR反转录出目的DNA．结果：琼脂糖凝胶电泳显示其PCR产物只有一条DNA条带且与目的基因大小一致，而阴性对照未见任何条带．结论：hZP3嵌和肽基因在重组病毒感染的昆虫细胞中成功转录，初步验证了目的基因的表达．     

Urotensin Ⅱ increases endothelin production by vascular smooth muscle cells in rats

The aim of this study was to observe the effects of urotensin Ⅱ (UII) on production of endothelin (ET) in rat aortic vascular smooth muscle cells (VSMC). Cultured VSMCs incubated with various concentrations of UII were used to measure the VSMC ³H-TdR incorporation, the amount of ET mRNA and ET production in VSMCs. In this work we found that UII (10^-10—10^-8 mol/L) promoted VSMC ³H-TdR incorporation (47%—83%, P < 0.01) and increased the amount of ET mRNA by 17.1% (P < 0.05) to 112.8% (P < 0.01), respectively, in a concentration dependent manner compared with control. After 4 and 8 h incubation, 10^-10—10^-8 mol/L of UII elevated the ET synthesis and release in a concentration dependent manner. After 4 h incubation, the content of ET in medium was 4.9, 5.36 and 7.12 pg/mL (P < 0.01). After 8 h incubation, the ET content released from VSMCs was 12.6, 12.07 and 17.17 pg/mL (P < 0.01). In addition, it was found that BQ₁₂₃, a specific ET_A receptor antagonist, obviously decreased the VSMC DNA synthesis induced by UII. The results of this study showed that UII could stimulate the ET mRNA expression and ET production in VSMC. The effects of UII on VSMC DNA synthesis were partly mediated by ET autocrine pathway. It suggests that the interaction between UII and ET plays an important biological regulating role as endogenous active peptides.     

Adrenomedullin inhibits the endothelin production induced by urotensin II in rat vascular smooth muscle cells

The aim of this study was to observe the effects of adrenomedullin (ADM) on endothelin (ET) production induced by urotensin Ⅱ (UⅡ) in rat vascular smooth muscle cells (VSMCs). Cultured VSMCs which were incubated with UⅡ (10^-8 mol/L) and with various concentrations of ADM were used to measure the VSMCs ³H-TdR incorpora- tion, the activity of extracellular signal-regulated kinase (ERK), the amount of ET mRNA and ET production in VSMCs. In this work we found that incubation with UⅡ(10^-8 mol/L) increased obviously the amount of ET mRNA in VSMCs and ET production in medium, however, coincubation with ADM (10^-10—10^-8 mol/L) and UⅡ(10^-8 mol/L) reduced the amount of ET mRNA by 15%, 24% and 45% (P< 0.01) respectively, compared with UⅡ alone. The content of ET in medium was 14.13, 11.38 and 11.00 pg/mL. ADM alone (10^-8 mol/L) had no effect on ET production in VSMCs. UⅡ (10^-8 mol/L) promoted the 3H-TdR incorpo- ration and activity of ERK in VSMCs. ADM inhibited VSMCs 3H-TdR incorporation and activation of ERK in a concentration-dependent manner. Compared with UⅡ group, after coincubation with ADM (10^-10—10^-8 mol/L) and UⅡ (10^-8 mol/L) the VSMCs 3H-TdR incorporation was decreased by 7% (P > 0.05), 32% (P < 0.05) and 41% (P < 0.01), respectively, and the activity of ERK was decreased by 24% (P > 0.05), 32% (P < 0.05) and 36% (P < 0.05), re- spectively, in a concentration-dependent manner. The results show that in cultured VSMCs ADM inhibits ET mRNA expression, ET production and proliferation stimulated by UⅡ, and that inhibitory effect of ADM on UⅡ bioaction could be mediated through inhibiting MAPK pathway.     

组合化学技术中的组合合成与群集筛选

本文叙述了组合化学技术的研究与应用，包括诸如同步多重合成（混合固相合成）法、多头合成（多针合成）法、茶袋法、光印（光控合成）法、反应珠法、载体合成法、基因重组法、非肽类岸法、色谱条码法等及其检测方法。它们已成为寻找和发展分子多样性与研究开发新药的策略和途径。     

云芝糖肽对裸鼠荷人肝癌的抑制作用

比较了云芝糖肽（Ｐｏｌｙｓａｃｃｈａｒｉｄｅ—ｐｒｐｔｉｄｅｏｆＣｏｒｉｏｌｕｓｖｅｒｓｉｃｏｌｏｒ，ＰＳＰ）单方和云芝糖肽复方（ＰＳＰ＋丹参＋川芎＋黄芪）对荷人肝癌ＢＡＬＢ／Ｃ裸鼠的治疗作用，并观察了裸鼠体内脂质过氧化物（ＬＰＯ）和超氧化物歧化酶（ＳＯＤ）的变化．试验结果表明，ＰＳＰ单方和复方按０．５～１．０ｇ／ｋｇ（体重）．ｄ连续用药２８天，对裸鼠荷人肝癌有明显的抑制作用，抑瘤率为５２％～５８％，增加药物剂量并不增强其抑瘤效果。裸鼠红细胞内５ＯＤ活性与对照组相比明显增强（单方：Ｐ＜０．０５；复方：Ｐ＜０．０１）．裸鼠血浆内ＬＰＯ含量有所下降，而以ＰＳＰ复方组对裸鼠血浆中过氧化反应的减弱更为显著。提示ＰＳＰ单方和复方的抑瘤效应可能与提高宿主的抗氧化能力有关。     

大肠杆菌中人心钠素基因在P_L和T7启动子控制下的高效表达

将Ｐ１噬菌体的ｒｅｆ基因与人心钠素的嵌合基因ＲＥＦ－ＡＮＰ分别克隆入带Ｐ＿Ｌ启动子和Ｔ７启动子的两种表达载体，获得高效表达重组质粒ｐＺＪＭ１和ｐＺＪＭ４．ｐＺＪＭ１转化ＤＨ５α、ｐＺＪＭ４转化ＨＭＳ１７４，在表达细菌培养到ＯＤ＿（６００）＝０．２５时分别进行温度诱导和化学诱导，快速凝胶扫描结果表明ＲＥＰ－ＡＮＰ表达量各占细菌可溶性总蛋白的６７．１％和２８．１％；在ＯＤ＿（６００）＝１．０或２．０时进行诱导，均能维持高效表达；且温度诱导的表达效率总是优于化学诱导。     

生长激素释放肽（GHRP）的合成及促生长效应

采用Ｍｅｒｒｉｆｉｌｄ固相法合成了生长激素释放肽，其氨基酸序列为Ｈｉｓ－Ｄ－Ｔｒｐ－Ａｌａ－Ｔｒｐ－Ｄ－ｐｈｅ－Ｌｙｓ－ＮＨ２．ＨＰＬＣ分析纯度为９７．７％，氨基酸组分分析与理论值吻合。以窿不同剂量对１５、２５及３５日龄小鼠的生长效应，１０００μ／齐量可使小鼠体重较对照组增加１５．２％，当剂量高达１０ｍｇ／ｋｇ时仍安全无毒。     

天蚕素A- 蜂毒素杂合肽基因的克隆*

杂合肽天蚕素（１－７）蜂毒素（５－１２）是一个只有１５个氨基酸残基的短肽，是具有疏水性Ｃ－端和亲水性Ｎ－端的双性分子．它的分子大小只相当于天蚕素Ａ的４０％，而抗菌活性相当于完整天蚕素，或更高．本文根据其氨基酸顺序设计一个４５ｂｐ的杂合肽基因，通过接头克隆到载体ｐＶＴ１０２－Ｕ上，在酵母中表达，用比浊法初步测定表明表达产物具有抗Ｅ．ｃｏｌｉＤ３１活性．