烟曲霉与人肺上皮细胞中E-cadherin相结合蛋白的初步研究

Preliminary study on the proteins in Aspergillus fulmigatus which can bind to E-cadherin in human pulmonary epithelial cells

目的烟曲霉是重要的条件致病真菌,可引起侵袭性肺曲霉病,而侵袭上皮细胞是烟曲霉致病的第一步。侵袭过程涉及的相关分子及其入侵机制尚不明确。上皮细胞的黏附分子E-cadherin可以和烟曲霉结合,并参与烟曲霉黏附侵袭上皮细胞的过程。本研究旨在探讨烟曲霉的致病机制,研究烟曲霉中和人肺泡上皮细胞黏附分子E-cadherin结合的蛋白。方法通过生物信息学方法,以分子机制明确的李斯特菌中可以和E-cadherin结合的蛋白功能域为模板在烟曲霉中搜索,分析目标蛋白。通过免疫共沉淀来了解目标蛋白的大小,从而初步推测目标蛋白。结果烟曲霉中与李斯特菌中可以和E-cadherin结合的蛋白功能域相似的序列为XP750927.1、XP750245.1、XP752100.1、XP748256.1;XP748256.1相对分子质量为45×103,而免疫共沉淀分析目标蛋白相对分子质量为50×103。结论 XP748256.1可能为烟曲霉中与E-cadherin结合的蛋白。

Objective Aspergillus fumigatus is an important opportunity pathogen. Its invasion of epithelial cells is the first step in the pathogenesis of aspergillosis. The related molecular mechanism of the invasion process is not clear. E cadherin in epithelial cells can bind to Aspergillus fumigatus, which may contribute to adhesion and invasion of Aspergillus fumigatus. To investigate the pathogenic mechanisms of Aspergillus fumigatus, we studied the relevant proteins in Aspergillus fulmi gate which can bind to E-cadherin of humans. Methods By bioinformatic methods, the functional domain in Listeria rnonocyto genes which is known can bind to E-cadherin protein was used as a template to search and analyze target proteins in the genome of Aspergillus fumigatus. The size of the target protein was determined by co-immunopreeipitation. Results Four proteins （XP750927.1, XP750245.1, XP752100.1, XP748256. 1） showed similar functional domain as in Listeria monocytogenes. The relative molecular mass of XP748256.1 is 45 x 103. Co-immunoprecipitation revealed that the relative molecular mass of the target protein is a bout 50 x 103. Conclusions XP748256.1 in Aspergillus fumigatus may be one of the proteins binding to E-cadherin.