灵芝免疫调节蛋白LZ-8的制备和晶体分析

Expression and crystallographic studies of a fungal immunomodulatory protein LZ-8 from a medicinal fungus Ganoderma lucidum

摘要:

LZ-8蛋白是从灵芝菌丝中分离到的真菌免疫调节蛋白，具有多种免疫调节功能，然而这一蛋白的作用机制尚不清楚。通过蛋白质晶体结构的解析，能够得到蛋白质空间结构特点，从而阐述蛋白质功能的机制。旨在得到LZ-8蛋白的晶体，并获得空间结构数据。以pET21a为表达载体，获得诱导表达的rLZ-8，通过亲和层析、分子筛凝胶层析和阴离子交换层析纯化，蛋白纯度在98％以上，采用悬滴气相扩散法得到蛋白晶体，并获得3.2?数据，为进一步对真菌免疫调节蛋白功能和结构的研究奠定了基础。

Abstract:

LZ-8 protein, isolated from a well known Chinese traditional medicinal fungus Ganoderma lucidum, is the first member of fungal immunomodulatory protein, members of which have been isolated from a variety of medicinal and edible mushrooms in the last two decades. The protein plays a multifunctional and important role in modulating immune system. In this report, in order to get LZ-8 protein crystals, the LZ-8 gene was expressed and purified by affinity chromatography, gel filtration chromatography and anion exchange chromatography subsequently. The protein was then crystallized using the hanging-drop vapour-diffusion method. The LZ-8 crystals were obtained and the phase information was calculated by X-ray diffraction. The resolution of LZ-8 crystals is 3.2?. This study will provide an insight into the structure of fungal immunomodulatory proteins.