Dry-Heating of Lysozyme Increases Its Activity against Escherichia coli Membranes
Dry-Heating of Lysozyme Increases Its Activity against Escherichia coli Membranes
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DOI：
10.1021/jf405155p
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发表时间：
2014-02-19
影响因子：
6.1
通讯作者：
Nau, Francoise
中科院分区：
文献类型：
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作者：
Derde, Melanie;Guerin-Dubiard, Catherine;Nau, Francoise
对于食品以及医疗应用，对新型和天然抗微生物分子的兴趣越来越大。溶菌酶是一个有前途的候选人为发展这样的分子。这种蛋白质被大量研究，并以其对革兰氏阳性菌的溶菌酶活性而闻名，但它也显示出对革兰氏阴性菌的抗微生物活性，特别是当先前修饰时。研究了干热溶菌酶（DH-L）对大肠杆菌的活性，并与天然溶菌酶（N-L）进行了比较。而N-L仅延迟细菌生长，DH-L导致早期种群减少。伴随的膜透化表明DH-L与N-L相比在外膜中诱导更大的孔或更多的孔，以及在内膜中诱导更多的离子通道。通过光学显微镜和原子力显微镜观察到了E.大肠杆菌细胞用DH-L处理的结果与所提出的膜完整性的干扰一致。干热诱导DH-L的疏水性、表面活性和正电荷增加可能是DH-L对E. coli膜。
For food as well as for medical applications, there is a growing interest in novel and natural antimicrobial molecules. Lysozyme is a promising candidate for the development of such molecules. This protein is largely studied and known for its muramidase activity against Gram-positive bacteria, but it also shows antimicrobial activity against Gram-negative bacteria, especially when previously modified. In this study, the activity of dry-heated lysozyme (DH-L) against Escherichia coli has been investigated and compared to that of native lysozyme (N-L). Whereas N-L only delays bacterial growth, DH-L causes an early-stage population decrease. The accompanying membrane permeabilization suggests that DH-L induces either larger pores or more pores in the outer membrane as compared to N-L, as well as more ion channels in the inner membrane. The strong morphological modifications observed by optical microscopy and atomic force microscopy when E. coli cells are treated with DH-L are consistent with the suggested disturbances of membrane integrity. The higher hydrophobicity, surface activity, and positive charge induced by dry-heating could be responsible for the increased activity of DH-L on the E. coli membranes.