Feng Yun, Huang Ning, Wu Qi, Bao Lang, Wang Bo-yao
Research Unit of Infection and Immunity, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Acta Pharmacol Sin. 2005 Sep;26(9):1087-92. doi: 10.1111/j.1745-7254.2005.00132.x.
To examine the antimicrobial spectrum and functional structure of high mobility group nucleosomal binding domain 2 (HMGN2).
OMIGA protein structure software was used to analyze the two-dimensional structure of HMGN2. Synthetic short peptides were generated for studying the relationship between function and structure. Prokaryotic expression vectors were constructed for the holo-HMGN2 and its helical domain. Their E coli-based products were also prepared for antimicrobial testing. The antimicrobial assay included minimal effective concentration, minimal inhibitory concentration, and minimal bactericidal concentration.
OMIGA protein structure software analysis revealed a transmembrane alpha-helical structure (the putative antimicrobial domain) located from position 18 to 48 of the HMGN2 protein sequence. The antimicrobial assay showed that the MIC of the recombinant holo-HMGN2 against E coli ML-35p (an ampicillin-resistance strain), Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 10231 were 12.5, 25, and 100 mg/L, respectively. Against the same microorganisms, the MIC of the synthetic HMGN2 alpha-helical domain were 12.5, 25, and 100 mg/L, respectively, that is, the same as with the recombinant form of HMGN2. In contrast, recombinant holo-HMGN2 was inactive against Staphylococcus aureus ATCC 25923. The synthetic N-terminal and C-terminal fragments of HMGN2 had no antimicrobial activity against E coli ML-35p, P aeruginosa ATCC 27853 or C albicans ATCC 10231.
HMGN2 showed potent antimicrobial activity against E coli ML-35p, P aeruginosa ATCC 27853 and, to some extent, against C albicans ATCC 10231, but was inactive against S aureus ATCC 25923 in these assay systems. Itos alpha-helical structure may be essential for the antimicrobial activity of HMGN2.
研究高迁移率族核小体结合域2（HMGN2）的抗菌谱及功能结构。
使用OMIGA蛋白质结构软件分析HMGN2的二维结构。合成短肽以研究功能与结构之间的关系。构建全HMGN2及其螺旋结构域的原核表达载体。还制备了基于大肠杆菌的产物用于抗菌测试。抗菌测定包括最小有效浓度、最小抑菌浓度和最小杀菌浓度。
OMIGA蛋白质结构软件分析显示，HMGN2蛋白序列第18至48位存在跨膜α螺旋结构（推测的抗菌结构域）。抗菌测定表明，重组全HMGN对大肠杆菌ML-35p（氨苄青霉素耐药菌株）、铜绿假单胞菌ATCC 27853和白色念珠菌ATCC 10231的最小抑菌浓度分别为12.5、25和100mg/L。针对相同微生物，合成的HMGN2α螺旋结构域的最小抑菌浓度分别为12.5、25和100mg/L，即与重组形式的HMGN2相同。相比之下，重组全HMGN2对金黄色葡萄球菌ATCC 25923无活性。HMGN2的合成N端和C端片段对大肠杆菌ML-35p、铜绿假单胞菌ATCC 27853或白色念珠菌ATCC 1023均无抗菌活性。
在这些测定系统中，HMGN2对大肠杆菌ML-35p、铜绿假单胞菌ATCC 27853以及在一定程度上对白色念珠菌ATCC 10231显示出强效抗菌活性，但对金黄色葡萄球菌ATCC 25923无活性。其α螺旋结构可能是HMGN2抗菌活性所必需的。
