Effects of oral administration recombinant Saccharomyces cerevisiae expressing human-salmon calcitonin on hypercalcemia rats~

Recombinant human-salmon calcitonin (hsCT) was synthesized and expressed on the cell surfaces of recombinant Saccharomyces cerevisiae (yAGA2-hsCT) using the pAGA2-hsCT expression vector.Expression of r...     

腺病毒介导的SPINK6表达在肝癌细胞QGY-7703中功能的初步研究

为了探讨SPINK6对肝癌细胞的抑制作用,使用缺陷型腺病毒载体构建载有SPINK6基因的重组腺病毒,感染肝脏肿瘤细胞QGY-7703,上调SPINK6蛋白的表达.通过CCK8细胞增殖实验和软琼脂克隆形成实验证实SPINK6对QGY-7703细胞生长的抑制,通过Transwell实验和细胞划痕试验证实SPINK6对QGY-7703细胞的体外细胞迁移与侵袭能力的抑制,为我们进一步揭示SPINK6的作用机制奠定了基础.     

重组质粒pEgr-1-TRAIL辐射诱导乳腺癌细胞效应的实验研究

目的将具有辐射诱导表达特性的重组质粒p Egr-1-TRAIL转入乳腺癌MCF-7细胞中,诱导肿瘤杀伤基因TRAIL的表达,实现辐射和基因对MCF-7细胞的双重杀伤效应.方法用ELISA法检测不同剂量X射线诱导TRAIL表达的量效关系及2 Gy X射线照射后不同时间TRAIL的表达;用流式细胞仪检测不同处理组MCF-7细胞早期凋亡情况.结果不同剂量X射线照射转染p Egr-1-TRAIL重组质粒的乳腺癌细胞MCF-7,TRAIL表达量明显高于假照组(P0.001~0.05),其中5 Gy X射线照后表达量最高,TRAIL表达量为假照组的5.1倍.2 Gy X射线照射后4 h,TRAIL表达量明显升高(P0.05),并随时间延长逐渐增加,照射后32 h达峰值,表达量为照射前的4.6倍.MCF-7-p Egr-1-TRAIL/0 Gy组早期凋亡细胞百分数较MCF-7/0 Gy和MCF-7-p3.1Egr/0 Gy组明显增加(P0.01),随着照射剂量的增加,MCF-7-p Egr-1-TRAIL/5 Gy组细胞早期凋亡率与其他处理组比较均存在统计学意义(P0.001~0.05),MCF-7/0 Gy组细胞生长最快,而MCF-7-p Egr-1-TRAIL/8 Gy组细胞生长最慢.结论乳腺癌细胞转染p Egr-1-TRAIL重组表达质粒联合X射线照射能够增加MCF-7细胞凋亡,抑制其生长.     

Establishment ofChlamydomonas reinhardtii chloroplast expression

An expression vector pACⅢ containing the chimeric gene HAV- VP3P1 and HCV-C gene has been constructed and transferred to C. reinhardtii by the biolistic method. The trans-formants have been identified by PCR, Southern-blotting, Northern-blotting and Western-blotting assays after selecting on resistant medium and incubating in the dark. The results show that the chimeric gene has replaced the chIL gene of C. reinhardtii chloroplast genome and expressed correctly under the control of the C. reinhardtii chloroplast double promoters 5' chlL-5' atpA. The analysis of SDS-PAGE indicates that the expressed protein accounts for 5.31 % of total soluble protein.     

电击法转移含人凝血因子IX基因重组质粒的影响因素

反转录病毒载体在基因治疗中可能会产生野生型病毒颗粒而引起安全性问题，本文研究含ＦＩＸｃＤＮＡ重组质粒基因治疗血友病Ｂ的可能，构建了不具反转录病毒载体结构的两重组质粒ｐＳＣＩＸＴＮ和ｐＣＩＸＴＮ，前者合ＳＶ４０早期启动子和ｈＣＭＶ启动子共同控制的ＦＩＸｃＤＮＡ，后者仅含ｈＣＭＶ启动于控制的ＦＩＸｃＤＮＡ，它们都含有ＴＫ启动于驱动的ｎｅｏ基因，通过电击法将基因转移到ＰＡ３１７和ＨＴ１０８０细胞，在ＨＴ１０８０细胞中的ＦＩＸ表达量分别为２２０、２１２ｎｇ／（１０６细胞·２４ｈ）通过与ｐＣＭＶＩＸ共转染靶细胞，可以增加人ＩＸ因子表达１．５～３．５倍，显示了用质粒载体转染靶细胞在血友病Ｂ基因治疗中是一条潜在可行的途径．本项研究用自制的电击仪转移ＰＡ３１７和ＨＴ１０８０等细胞，最高的转移效率达１０－３，并探讨了细胞种类，ＤＮＡ量，ＤＮＡ结构，电压，脉冲时间与转移效率及表达量的关系．     

Production of functional rat liver PSP protein in Escherichia coli

An efficient Escherichia coli expression system for the production of a perchloric acid-soluble protein (PSP) has been constructed. Complementary DNA encoding PSP was inserted into an inducible bacterial expression vector pGEX-4T-1. After the plasmid introduced into E. coli was expressed by isopropyl 1-thio-β-D-galactopyranoside (IPTG), the recombinant product was purified by glutathione-Sepharose 4B affinity chromatography. The purified product showed the expected NH₂-terminal sequence, but the translation inhibitory activity of this product was 10 times lower compared with that of authentic PSP isolated from rat liver. Received 8 October 1998; received after revision 6 November 1998; accepted 6 November 1998     

用ELISA双抗体夹心法检测人重组白细胞介素2(rHuIL-2)在酵母菌中表达的研究

采用ELISA夹心法检测人重组IL-2在酵母菌中表达产物的免疫学活性.结果表明,本法具有特异性强、简易、快速和重复性好等特点,尤其对利用工程菌制备及纯化rlL-2过程中能较快地监测出是否有该产物表达.     

毕氏酵母流加发酵过程的比生长速率控制

在已建立的毕氏酵母发酵过程结构模型基础上，进行了甲醇流加阶段恒定比生长速率控制研究。实验结果表明，基于模型的甲醇进料策略可以将细胞比生长速率恒定地控制在设定值；在比生长速率均值相等的情况下，恒定比生长速率进料策略较之恒速进料策略蛋白产量更高。