Journal: Redox Biology

Article Title: Formation of a reducing microenvironment and regulation of protein supersulfidation by gut microbial supersulfides

doi: 10.1016/j.redox.2026.104123

Figure Lengend Snippet: Supersulfides mediate interbacterial crosstalk (A) The levels of CysSSH in the culture supernatant were quantified by LC-ESI-MS/MS. (B) Each bacterial strain was anaerobically incubated with fecal suspension with or without cystine, and intracellular reactive sulfur levels were quantified as NEM-S-NEM by LC-ESI-MS/MS. (C) L. reuteri was anaerobically incubated with NAC-S2 and intracellular sulfane sulfur levels were quantified by LC-ESI-MS/MS. Data are expressed as the means ± SEM. Statistical significance was assessed using one-way ANOVA with the Tukey's multiple comparisons test in (A) and (C). ∗∗ p < 0.01; ∗∗∗ p < 0.001.

Article Snippet: The medium was replaced with fresh MRS broth containing 250 μM NAC-S2 (Peptide Institute, Inc., Osaka, Japan), and the cells were anaerobically incubated for 30 min at 37 °C, followed by washing with D-PBS(−).

Techniques: Tandem Mass Spectroscopy, Incubation, Suspension

Journal: Redox Biology

Article Title: Formation of a reducing microenvironment and regulation of protein supersulfidation by gut microbial supersulfides

doi: 10.1016/j.redox.2026.104123

Figure Lengend Snippet: Profiling and environmental modulation of gut bacterial supersulfidome (A) Gel image showing supersulfidated proteins from various bacterial strains isolated using a pull-down method. Black bands indicate supersulfidated proteins. (B) Violin plot of quantified protein abundances (log-scale) for the identified proteins ( L. reuteri ; n = 917, E. bolteae ; n = 2064). The dashed line represents the median, and the dotted lines represent the first and third quartiles, respectively. (C) L. reuteri was anaerobically incubated with NAC-S2, and total supersulfidated cysteine residues were quantified by LC-ESI-MS/MS. (D) Rank plots of log2-transformed protein abundance ratio values represent changes in protein supersulfidation levels in L. reuteri following NAC-S2 stimulation. Proteins are sorted by their fold change values. Red indicates upregulated proteins (>2-fold), and blue indicates downregulated proteins (<0.5-fold). Detailed information regarding individual proteins is listed in . (E) Top 10 supersulfidated proteins enriched in the cystine (+) condition. All identified proteins were ranked based on their -fold change compared to the cystine (−) group. Detailed information concerning individual proteins is listed in . Data are expressed as means ± SEM. Statistical significance was assessed using Mann–Whitney U test in (B) or unpaired Student's t -test in (C). ∗∗∗ p < 0.001.

Article Snippet: The medium was replaced with fresh MRS broth containing 250 μM NAC-S2 (Peptide Institute, Inc., Osaka, Japan), and the cells were anaerobically incubated for 30 min at 37 °C, followed by washing with D-PBS(−).

Techniques: Isolation, Incubation, Tandem Mass Spectroscopy, Transformation Assay, Quantitative Proteomics, MANN-WHITNEY