兽疫链球菌透明质酸合成相关基因hasB的克隆以及性质研究

透明质酸是链球菌荚膜的主要组成部分,有着重要的生理功能。UDP-葡萄糖脱氢酶(HasB)是透明质酸合成中的一个关键酶,而C类链球菌的UDP-葡萄糖脱氢酶编码基因(hasB)尚未被克隆。通过hasB基因的上下游序列设计引物从兽疫链球茵的基因组中克隆出一段序列,测序结果显示其包含一个由1206个碱基组成的开放阅读框,所编码的蛋白序列同化脓链球菌和乳链球菌的UDP-葡萄糖脱氢酶蛋白序列分别有63.1%和70.6%的相似性。将这段基因置于T7启动子下,并在大肠杆菌中进行表达,能够得到一个约47kDa的蛋白,酶活测定显示其具有UDP-葡萄糖脱氢酶活性。这些结果表明所克隆的基因是兽疫链球菌的UDP-葡萄糖脱氢酶编码基因。

马链球菌兽疫亚种hasB基因功能的研究

为了阐明马链球菌兽疫亚种(Streptococcus equi ssp.zooepidemicus,SEZ)荚膜的致病机理,使该菌引起的猪、马、牛等多种动物的链球菌病得到有效控制,试验采用Real-time PCR技术分析has B基因的体内表达特性,通过构建基因缺失突变菌株、调理吞噬试验等对has B基因的致病性进行系统评价。结果表明:相对于体外培养的细菌,SEZ感染小鼠脾脏分离细菌的mRNA表达均显著下调;基因缺失突变菌株Δhas B与亲本菌株的生长状况基本一致,但是致病力显著降低;基因缺失突变菌株Δhas B影响补体和巨噬细胞介导的免疫反应,使其抵抗宿主巨噬细胞的吞噬能力显著降低。

Evonik Strengthens Its Investment in R&D

To cope with the current difficult financial situation worldwide,most of the compa-nies plan to cut down their cost significantly,however,on October 1st,2008 Evonik Industries opened

PU Sizing Agent Sector Starts Reform

Polyurethane (PU) sizing agent is athermoplastic PU elastomer exten-sively used in synthetic leather, arti-ficial deerskin and electrostatic flock-ing sectors. The drastic productionand demand increase of syntheticleather in China in recent years haspromoted rapid consumption growthof PU sizing agent.

Court Reconfirms Sinorgchem's Non-Infringement Position in Patent Case

Concluding a five-year legal dispute withFlexsys America L.P.,the U.S.DistrictCourt in Ohio entered a final judgment ofnon-infringement for Jiangsu Sinorgchemand its subsidiaries.On July 6th,2010,the Ohio Court grantedSinorgchem defendants’ motion for summaryjudgment,finding that they did