Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India.
Genomics Proteomics Bioinformatics. 2011 Oct;9(4-5):151-7. doi: 10.1016/S1672-0229(11)60018-1.
Leptospirosis is an infectious bacterial disease caused by Leptospira species. In this study, we cloned and sequenced the gene encoding the immunodominant protein GroEL from L. interrogans serovar Autumnalis strain N2, which was isolated from the urine of a patient during an outbreak of leptospirosis in Chennai, India. This groEL gene encodes a protein of 60 kDa with a high degree of homology (99% similarity) to those of other leptospiral serovars. Recombinant GroEL was overexpressed in Escherichia coli. Immunoblot analysis indicated that the sera from confirmed leptospirosis patients showed strong reactivity with the recombinant GroEL while no reactivity was observed with the sera from seronegative control patient. In addition, the 3D structure of GroEL was constructed using chaperonin complex cpn60 from Thermus thermophilus as template and validated. The results indicated a Z-score of -8.35, which is in good agreement with the expected value for a protein. The superposition of the Ca traces of cpn60 structure and predicted structure of leptospiral GroEL indicates good agreement of secondary structure elements with an RMSD value of 1.5 Å. Further study is necessary to evaluate GroEL for serological diagnosis of leptospirosis and for its potential as a vaccine component.
钩端螺旋体病是一种由钩端螺旋体属细菌引起的传染病。在这项研究中，我们从印度钦奈钩端螺旋体病爆发期间从患者尿液中分离出的 Autumnalis 血清型 L. interrogans 菌株 N2 中克隆和测序了编码免疫显性蛋白 GroEL 的基因。该 groEL 基因编码一种 60 kDa 的蛋白质，与其他钩端螺旋体血清型具有高度同源性（99%相似性）。重组 GroEL 在大肠杆菌中过表达。免疫印迹分析表明，来自确诊钩端螺旋体病患者的血清与重组 GroEL 表现出强烈的反应性，而来自血清阴性对照患者的血清则没有反应性。此外，使用嗜热栖热菌的伴侣蛋白复合 cpn60 作为模板构建了 GroEL 的 3D 结构，并进行了验证。结果表明 Z 分数为-8.35，与预期的蛋白质值非常吻合。cpn60 结构和预测的钩端螺旋体 GroEL 的 Ca 轨迹的叠加表明二级结构元件具有良好的一致性，均方根偏差值为 1.5 Å。需要进一步研究以评估 GroEL 用于钩端螺旋体病的血清学诊断及其作为疫苗成分的潜力。
