新疆药用延胡索资源调查

作者对新疆维吾尔自治区的9个市、县进行了药用延胡索的资源调查,采集植物标本70余份,弄清药用种类主要是3种,即Corydalis glaucescens Regel,C.ledebouriana Kir.et Kar.和C.schanginii(Pall.)Fedtsch.;初步了解了3种药用延胡索植物的分布状况,并对块茎中总生物碱的含量作了分析。     

Crystallization and main-chain structure of neutral protease from Streptomyces caespitosus

A neutral protease, i.e., a zinc-containing metalloendoprotease from Streptomyces caespitosus, has been crystallized using acetone as a precipitating agent. The crystals diffract to better than 1.5 A resolution when a rotating anode X-ray generator is used as an X-ray source. Protein phase angles were calculated by the multiple isomorphous replacement method using two heavy-atom derivatives (HgCl2 and CH3HgCl). A 6 A resolution electron density map clearly showed molecular boundaries. Although its amino acid sequence is not known, the folding pattern of the polypeptide chain could be traced on a 2.5 A resolution electron density map. A large cleft, which is located on the molecular surface, was proved to be the active site of the enzyme by structure analyses of inhibitor-complex crystals. The highest electron density peak, which corresponds to the cleft, was assigned to a catalytically essential zinc atom on difference Fourier synthesis between native and EDTA-soaked crystals.     

应用杆状病毒载体在昆虫细胞系统中表达乙型肝炎病毒表面抗原基因

构建了同时带有乙型肝炎病毒表面抗原基因和大肠杆菌的β-半乳糖苷酶基因的杆状病毒转移载体质粒pVL941lacHBS。应用磷酸钙沉淀技术将pVL941lacHBS DNA转入事先用AcNPV感染过的Sf9细胞,在显色剂X-gal存在下,筛选无多角体的蓝色蚀斑。经过若干次蚀斑纯化,最后获得含乙肝病毒表面抗原基因和β-半乳糖苷酶基因的重组杆状病毒R-AcV941LS。 用R-AcV941LS感染Sf9细胞,在感染后72～96小时,用RPHA和RIA分别检测组织培养上清液和细胞裂解液中的乙型肝炎病毒表面抗原含量。结果,组织培养上清液为3.83μg/1×10~6～2×10~6细胞;细胞裂解液为4.39μg/1×10~6～2×10~6细胞。乙型肝炎病毒表面抗原的合成总量为8.22μg/1×10~6～2×10~6细胞。免疫电镜观察显示表达产物呈约22nm的球形颗粒。小鼠免疫接种实验结果表明,以R-AcV941LS感染Sf9细胞表达的乙型肝炎病毒表面抗原与在哺乳动物细胞系表达的乙型肝炎病毒表面抗原具有相近似的免疫原性。     

人源性流行性出血热病毒的形态特征

本文报道流行性出血热病毒(汉坦病毒)H-114株的电镜形态。发现形态发生以内质网膜和胞浆膜芽生为主。病毒颗粒为圆形或卵圆形。具有双层膜结构,大小为90～120nm。提出了汉坦病毒形态发生的理论观点。