高迁移率族蛋白N2免疫组织化学定位及其活性结构抑菌性能的体外实验研究

Imtnunohistochemical localization and antimicrobial properties of high mobility group protein N2

目的研究高迁移串族蛋白N2(HMGN2)在猪组织中的免疫组织化学定位情况,体外评价HMGN2的活性结构α-螺旋的抑菌性能。方法采用免疫组织化学法,观察HMGN2蛋白在猪组织中的表达;采用高效液相色谱法从猪的胸腺和淋巴结中分离和纯化HMGN2,人工合成HMGN2的活性结构α-螺旋,采用液体稀释法体外评价HMGN2及HMGN2α-螺旋结构对变异链球菌、表兄链球菌、白假丝酵母菌及大肠杆菌的抑菌性能。结果从猪的胸腺和淋巴结中成功分离和纯化得到HMGN2,所有受检猪组织均呈HMGN2免疫阳性反应,且HMGN2多表达在组织细胞质和细胞核中;HMGN2和HMGN2α-螺旋结构抑菌活性相当,均对所选实验菌株均表现出不同的抑菌性能:结论 HMGN2可表达在猪组织的细胞浆和细胞核中,HMGN2及其活性结构α-螺旋具有较强的抑菌性能。

Objective To study immunohistochemical localization of high mobility group protein N2（HMGN2） protein in porcine tissues, and evaluate the antimicrobial activity of its active domain, α-helical domain in vitro. Methods In this study, we investigated the localization of HMGN2 protein in porcine tissues using the immunohistochemical method. In addition, we isolated and purified HMGN2 from porcine thymus and lymph node by the high-performance liquid chromatography（HPLC）, and then we synthesized α-helical domain of HMGN2. After that, we evaluated the antimicrobial activity of HMGN2 and α-helical domain of HMGN2, against Streptococcus mutans, Streptococcus sobrinus, Candida albicans and Escherichia coli in vitro. Results The results showed that HMGN2 could be isolated and purified from porcine thymus and lymph node, and all the tested porcine tissues were immunoreactive to HMGN2 proteins. The proteins mostly presented in the cytoplasm and nucleus. Synthetic α-helical domain of HMGN2 and HMGN2 had equivalent antibacterial activity, and both of them had potent antimicrobial activity against the selected bacteria and fungi. Conclusion The study suggested that the HMGN2 proteins mostly presented in the cytoplasm and nucleus in porcine tissues, and HMGN2 and synthetic α-helical domain of HMGN2 had potent antimicrobial activity against some bacteria and fungi.