酸土脂环酸芽孢杆菌Fe-SOD基因克隆及生物信息学分析

酸土脂环酸芽孢杆菌具有嗜酸耐热的独特生理特性,从该属细菌中分离到的多种酶类都具有耐酸热稳定性,是筛选耐酸耐热酶的重要菌种资源。超氧化物歧化酶(SOD)由于具有重要的生理功能而广泛用于食品、药品及化妆品等行业。为了深入探讨酸土脂环酸芽孢杆菌SOD的分子生物学特性,本研究利用同源克隆、交错式热不对称PCR技术和生物信息学方法进行Fe-SOD基因克隆、测序及序列分析。结果表明,Fe-SOD基因(GenBank序列号:JN614998)ORF全长为606bp,编码202个氨基酸,其推测氨基酸序列与来源于酸热脂环酸芽孢杆菌DSM446的Fe-SOD(ACV58017.1)序列相似性最高,为78%。整个蛋白序列含有Fe/MnSODs家族的5个模体,SOD活性中心含有金属离子结合配基His27、His82、Asp164和His168,具有Fe/MnSODs家族典型的蛋白结构特征。酸土脂环酸芽孢杆菌Fe-SOD基因的克隆和生物信息学分析为进一步构建原核表达载体、获得生产耐酸热Fe-SOD的基因工程菌株奠定基础。     

超氧化物歧化酶氨基酸网络的鲁棒性研究

蛋白质结构的鲁棒性能够提高蛋白质在不稳定环境中保持生物功能的能力。用氨基酸网络表示超氧化物歧化酶(Fe-SOD)的结构,从研究氨基酸网络鲁棒性的角度研究Fe-SOD结构的鲁棒性。实验结果显示,氨基酸网络的鲁棒性比同等规模大小的随机网络的鲁棒性差。尤其以介数方式攻击,Fe-SOD氨基酸网络表现出明显的脆弱性。嗜热的Fe-SOD氨基酸网络的鲁棒性比常温的氨基酸网络的鲁棒性高。通过鲁棒性分析,识别氨基酸网络中关键残基,发现关键残基主要包括进化保守残基、疏水性残基、规则二级结构内部的残基以及Fe-SOD活性位点残基。与热稳定性低的Fe-SOD氨基酸网络相比,热稳定性高的Fe-SOD氨基酸网络中的关键残基较均匀地分布在Fe-SOD内部。关键残基在Fe-SOD结构中均匀分布,有利于提高嗜热Fe-SOD整体的稳定性。     

In vitro Leishmanicidal and Trypanosomicidal Properties of Imidazole-Containing Azine and Benzoazine Derivatives

Leishmaniasis and Chagas diseases are two of the most important parasitic diseases in the world. Both belong to the category of Neglected Tropical Diseases, and they cannot be prevented by vaccination. Their treatments are founded in outdated drugs that possess many pernicious side-effects and they're not easy to administer. With the aim of discovering new compounds that could serve as anti-trypanosomal drugs, an antiparasitic study of a synthetic compound family has been conducted. A series of new 1,4-bis(alkylamino)- and 1-alkylamino-4-chloroazine and benzoazine derivatives 1 – 4 containing imidazole rings have been synthesized and identified. Their structures showed a possible interest based on previous work. Their in vitro anti-Leishmania infantum, anti-L. braziliensis, anti-L. donovani and anti-T. cruzi activity were tested, as well as the inhibition of Fe-SOD enzymes. It was found that some of them exhibited quite relevant values indicative of being worthy of future more detailed studies, as most of them showed activity to more than only one parasite species, especially compound 3 c was active for the three studied Leishmania species and also for T. cruzi, which is a very interesting trait as it covers a wide spectrum.