Response on “commentary on “using resonance synchronous spectroscopy to characterize the reactivity and electrophilicity of biologically relevant sulfane sulfur”. Evidence that the methodology is inadequate because it only measures unspecific light scattering”. The evidence is incorrect

Huanjie Li,Luying Xun,Huaiwei Liu,Qingda Wang

doi:10.1016/j.redox.2019.101312

Abstract

Response on “commentary on “using resonance synchronous spectroscopy to characterize the reactivity and electrophilicity of biologically relevant sulfane sulfur”. Evidence that the methodology is inadequate because it only measures unspecific light scattering”. The evidence is incorrect

Highlights

Sulfane sulfur, including HSnH and RSnH, n ≥ 2; RSnR, n ≥ 3, contains zero-valent sulfur (S0)
We recently discovered that biologically relevant sulfane sulfur species display strong optical signals when analyzed by resonance synchronous spectroscopy (RS2), in which excitation and emission wavelengths are essentially identical [2]
We reported that several sulfane sulfur species, including inorganic polysulfide (H2Sn, HSn−, and Sn2−), glutathioine persulfide (GSSH), protein persulfide, and organic polysulfide (RSnH, n ≥ 2 and RSnR, n ≥ 3) have RS2 signals, which are affected by pH if the sulfane sulfur species undergo protonation and deprotonation [2]

Summary

Introduction

Sulfane sulfur, including HSnH and RSnH, n ≥ 2; RSnR, n ≥ 3, contains zero-valent sulfur (S0). They showed colloidal sulfur, prepared by vortexing sulfur powder into water, displayed RS2 signals, suggesting that our reported RS2 of sulfane sulfur is due to light scattering of sulfur particles [3]. We performed a similar experiment, diluting inorganic polysulfide (26 mM stock in an alkaline solution [4]) to 1.5 μM in 50 mM Tris buffer (pH 7.4) for RS2 analysis.

Results

Conclusion