Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, 8092 ETH Zurich, Switzerland.
J Agric Food Chem. 2010 Oct 13;58(19):10315-22. doi: 10.1021/jf1010897.
The hydroxypropionaldehyde (HPA) system is a natural defense system synthesized by the probiotic bacterium Lactobacillus reuteri. To elucidate which of the molecules composing the HPA system (3-hydroxypropionaldehyde (3-HPA), reuterin (HPA dimer), and HPA hydrate) is responsible for the potent antimicrobial activity in biological systems, a combination of biochemical, genetic, and proteomic assays was used. The HPA system reacts with sulfhydryl-containing compounds such as cysteine and reduced glutathione (GSH) in solution. In situ, GSH knock-out Escherichia coli is significantly more susceptible to HPA-mediated cell death than E. coli wild type; GSH supplementation protects either bacteria from HPA attack. Proteomic analysis of HPA-treated bacteria ( Haemophilus influenzae ) revealed induction of redox- and heat shock-related proteins. A new antimicrobial mechanism of HPA is proposed, whereby the activity of HPA leads to depletion of free SH- groups in GSH and proteins through the action of 3-hydroxypropionaldehyde, causing an imbalance of the cellular redox status, ultimately resulting in cell death.
羟基丙醛（HPA）系统是由益生菌乳杆菌合成的一种天然防御系统。为了阐明 HPA 系统（3-羟基丙醛（3-HPA）、雷替丁（HPA 二聚体）和 HPA 水合物）中的哪种分子负责生物系统中的强大抗菌活性，使用了生化、遗传和蛋白质组学组合测定。HPA 系统与溶液中含巯基的化合物（如半胱氨酸和还原型谷胱甘肽（GSH））反应。在原位，GSH 敲除大肠杆菌比大肠杆菌野生型对 HPA 介导的细胞死亡更敏感；GSH 补充可保护两种细菌免受 HPA 的攻击。用 HPA 处理的细菌（流感嗜血杆菌）的蛋白质组分析显示，与氧化还原和热休克相关的蛋白质被诱导。提出了 HPA 的一种新的抗菌机制，即 HPA 的活性通过 3-羟基丙醛的作用导致 GSH 和蛋白质中游离 SH-基团的消耗，导致细胞氧化还原状态失衡，最终导致细胞死亡。
