H2O2-Mediated Oxidative Stress Enhances Cystathionine γ-Lyase-Derived H2S Synthesis via a Sulfenic Acid Intermediate

Abstract

Hydrogen sulfide (H2S), which is generated mainly by cystathionine γ-lyase (CSE) in the cardiovascular system, plays a pivotal role in a wide range of physiological and pathological processes. However, the regulatory mechanism of the CSE/H2S system is poorly understood. Herein, we show that oxidation induces the disulfide bond formation between Cys252 and Cys255 in the CXXC motif, thus stimulating the H2S-producing activity of CSE. The activity of oxidized CSE is approximately 2.5 fold greater than that of the reduced enzyme. Molecular dynamics and molecular docking suggest that the disulfide bond formation induces the conformational change in the active site of CSE and consequently increases the affinity of the enzyme for the substrate L-cysteine. Mass spectrometry and mutagenesis studies further established that the residue Cys255 is crucial for oxidation sensing. Oxidative stress-mediated sulfenylation of Cys255 leads to a sulfenic acid intermediate that spontaneously forms an intramolecular disulfide bond with the vicinal thiol group of Cys252. Moreover, we demonstrate that exogenous hydrogen peroxide (H2O2) and endogenous H2O2 triggered by vascular endothelial growth factor (VEGF) promote cellular H2S production through the enhancement of CSE activity under oxidative stress conditions. By contrast, incubation with H2O2 or VEGF did not significantly enhance cellular H2S production in the presence of PEG-catalase, an enzymatic cell-permeable H2O2 scavenger with high H2O2 specificity. Taken together, we report a new posttranslational modification of CSE that provides a molecular mechanism for H2O2/H2S crosstalk in cells under oxidative stress.

The Antioxidant Properties of Glucosinolates in Cardiac Cells Are Independent of H2S Signaling

“…The free thiol group in cysteine can be easily oxidized to sulfenic, sulfinic, and sulfonic acids, thus changing the activities of enzymes [34]. In cultured smooth muscle cells, H 2 O 2 incubation did not change the mRNA and protein levels of CSE but was able to promote the activity of CSE and increase H 2 S production [35]. However, in another study with human umbilical vein endothelial cells, H 2 O 2 suppressed H 2 S generation by directly reducing CSE protein expression [36].…”

Effects of constant darkness on behaviour and physiology of male and female mice

“…In males, 3 weeks of DD exposure resulted in alterations in glycine, serine, and threonine metabolism (cystathionine, sarcosine and glycerate) and ketone body metabolism (acetoacetate) (Figure 6a and Table S4). Previous studies have reported modulation of these pathways and metabolites in stress‐related psychiatric disorders (Chen et al, 2017; Wang et al, 2021; Yang et al, 2013). In females, 3 weeks of DD exposure modulated phenylalanine tyrosine and tryptophan metabolism (phenylalanine and phenylacetate metabolites), which are involved in synthesising neurotransmitters such as dopamine and norepinephrine (Figure 6B and Table S4).…”

NRF2 Regulates Cystathionine Gamma-Lyase Expression and Activity in Primary Airway Epithelial Cells Infected with Respiratory Syncytial Virus

“…Our past studies have demonstrated for the first time the antiviral and anti-inflammatory role of CSE/H 2 S both in vitro and in vivo, following in RSV infection [ 2 , 3 ]. The expression of CSE has not been extensively investigated, but it is known to be regulated by oxidative stress, as in the case of H 2 O 2 cell stimulation [ 23 ]. The transcription of many oxidative stress-inducible genes is regulated in part through cis -acting ARE sequences.…”