Investigation of structure and function of bacterial porins with special emphasis on their role in physiology of Borrelia and related species

革兰氏阴性细菌的细胞质被两层膜包围。外膜起到分子过滤器的作用。筛选器属性可以是常规的，也可以是特定的。小的亲水性分子以高速通过这些膜，通过被称为细菌孔蛋白的通道。该项目将涉及对这些孔蛋白通道的研究，特别是对疏螺旋体和相关螺旋体的外膜通道的研究，这些通道到目前为止还没有很好的特征。疏螺旋体是通过寄生虫叮咬传播不同疾病的原因。例如，伯氏疏螺旋体是莱姆型疏螺旋体病的病原体，并通过硬蜱传播。东半球硬蜱传播的复发性热(TBRF)是一种常见的地方病，由传播杜氏疏螺旋体的软体硬体硬蜱叮咬而在人类中引起。其他致病性疏螺旋体物种，如赫氏疏螺旋体和复发性疏螺旋体，也可通过抽搐传播或由虱子传播。螺旋体是宿主繁殖的细菌，在温血和节肢动物宿主之间循环，因此开发了先进的策略来感知并在这些环境中生存。疏螺旋体在不同宿主中通过外膜吸收营养物质在这些细菌的生活方式中起着重要作用，因为它们只有有限的代谢能力。这意味着营养物质通过孔道的运输对于疏螺旋体在宿主中的生存非常重要。不同种的疏螺旋体和其他螺旋体的外膜孔蛋白需要用不同的生化和生物物理方法进行鉴定、分离、纯化和表征。分子生物学将被用于鉴定和克隆孔蛋白基因。需要在大肠杆菌中重组表达孔蛋白基因，以便用不同的生化和生物物理方法进一步分析孔蛋白通道。

The cytoplasm of gram-negative bacteria is surrounded by two membranes. The outer membranes serve as molecular filters. The filter properties are either general or specific. Small hydrophilic molecules pass these membranes with high velocity through channels that are known as bacterial porins. The project will deal with the study of these porin channels with special emphasis on the study of outer membrane channels of Borrelia and related Spirochetes, which are not well characterized to date. Borrelia are the cause of different diseases transmitted by the bites of parasites. For example Borrelia burgdorferi is the etiologic agent of Lyme borreliosis and is spread by Ixodes tics. Old world tick-borne relapsing fever (TBRF), caused in humans by the bite of an infected soft body tick Ornithodorus moubata transmitting the pathogen Borrelia duttonii, is a common endemic disease in Central, East and South Africa. Other pathogenic Borrelia species such as B. hermsii and B. recurrentis are also transmitted by tics or are louse-born. Borrelia spirochetes are hostpropagated bacteria that cycle between warm-blooded and arthropod hosts and have therefore developed advanced strategies to sense and survive in these environments. Uptake of nutrients through the outer membrane of Borrelia in different hosts plays an important role in the lifestyle of these bacteria because they have an only limited metabolic capacity. This means that the transport of nutrients through porins is very for important for survival of Borrelia in their hosts. Outer membrane porins in different Borrelia species and other Spirochetes should be identified, isolated, purified and characterized by different biochemical and biophysical methods. Molecular biology will be used to identify and clone porin genes. Porin genes should be recombinantly expressed in Escherichia coli for further analysis of the porin channels in different biochemical and biophysical approaches.