Cuevasanta Ernesto, Möller Matías N, Alvarez Beatriz
Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Universidad de la República, Uruguay.
Center for Free Radical and Biomedical Research, Universidad de la República, Uruguay; Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
Arch Biochem Biophys. 2017 Mar 1;617:9-25. doi: 10.1016/j.abb.2016.09.018. Epub 2016 Sep 30.
Hydrogen sulfide (HS) has been traditionally considered to be a toxic molecule for mammals. However, it can be formed endogenously and exert physiological effects with potential health benefits. HS can partition two-fold in biological membranes and traverse them rapidly, diffusing between compartments. HS reactivity has similarities to that of thiols, although it is less nucleophilic than thiols and it can form different products. HS can react with oxidants derived from the partial reduction of oxygen, but direct scavenging is unlikely to explain HS protective actions. Important effects are exerted on mitochondria including the stimulation or the inhibition of the electron transport chain. Possible mechanisms for unleashing biological consequences are the reactions with metal centers and with thiol oxidation products. The reactions of HS with disulfides (RSSR) and sulfenic acids (RSOH) lead to the formation of persulfides (RSSH). Persulfides have enhanced nucleophilicity with respect to the corresponding thiol, consistent with the alpha effect. Besides, the inner and outer sulfurs can both act as electrophiles. In this review, we describe the reactions of HS with oxidized thiol products and the properties of the persulfides formed in the context of the chemical biology of HS.
传统上，硫化氢（HS）被认为是一种对哺乳动物有毒的分子。然而，它可以在体内生成并发挥具有潜在健康益处的生理作用。HS在生物膜中具有两亲性，能够快速穿过生物膜，在不同区室之间扩散。HS的反应性与硫醇相似，尽管其亲核性比硫醇弱，且能形成不同的产物。HS可以与部分还原氧产生的氧化剂发生反应，但直接清除作用不太可能解释HS的保护作用。HS对线粒体有重要影响，包括刺激或抑制电子传递链。引发生物学效应的可能机制是与金属中心以及硫醇氧化产物的反应。HS与二硫化物（RSSR）和亚磺酸（RSOH）的反应会导致过硫化物（RSSH）的形成。相对于相应的硫醇，过硫化物具有增强的亲核性，这与α效应一致。此外，内部和外部的硫都可以作为亲电试剂。在本综述中，我们描述了HS与氧化硫醇产物的反应以及在HS化学生物学背景下形成的过硫化物的性质。
