变异链球菌临床株表面相关蛋白表达差异的初步分析
Differential expression of surface-associated proteins in clinical isolations of Streptococcus mutans

摘要： 目的 探讨变异链球菌临床株在中性条件下表面相关蛋白的表达差异，进一步了解龋病的发生和发展过程。方法 在pH7.0条件下采用Homer法提取临床分离株的表面相关蛋白，经十二烷基硫酸钠聚丙烯酰胺凝胶（SDS-PAGE）电泳和二维电泳（2DE）确定蛋白质表达的差异条带及位点，差异位点由基质辅助激光解析电离飞行时间（MALDI-TOF）质谱分析，并结合数据库进行检索和鉴定蛋白质。结果 经过对电泳图谱的分析发现：593号菌株存在14个高表达蛋白质位点和8个特异蛋白质位点，其中丙酮酸激酶、ABC运载体（腺苷三磷酸结合蛋白）特异表达，葡糖基转移酶高表达。结论 两菌株在中性条件下出现了某些蛋白质的高表达和特异表达，可能是致龋性存在差异的原因。
Abstract: Objective This study aims to investigate the changes in the expression of surface-associated protein at pH7.0 in Streptococcus mutans isolated from clinical samples. Methods The proteins were extracted from the cells at pH7.0 by using the Homer method. The proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDSPAGE) and 2D gel electrophoresis(2DE) followed by image analysis. The proteins were identified by matrix-assisted laser desorption time of flight(MALDI-TOF) mass spectrometry and computer-assisted protein sequence analysis. Results Image analysis revealed that 14 high expression protein loci and 8 specific protein loci exist in Streptococcus mutans 593. Specifically, pyruvate kinase and adenosine triphosphate-binding cassette transporter were modulated, and glucose transferase was highly modulated in Streptococcus mutans 593. Conclusion The difference in protein expression of the two clinical isolations may indicate their distinct cariogenic characters.
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