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flavin-dependent sulfhydryl oxidase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: [protein]-dithiol + O2 = [protein]-disulfide + H2O2 using FAD as a cofactor, leading to formation of disulfide bridges in proteins. [PMID:10899311, PMID:19679655, PMID:35495482]

Flavin-dependent sulfhydryl oxidase activity is a critical enzyme function involved in the oxidation of thiol groups within proteins. This enzymatic activity is catalyzed by a family of enzymes known as sulfhydryl oxidases, which utilize flavin adenine dinucleotide (FAD) as a cofactor. The catalytic mechanism involves the following steps:

1. **Thiol substrate binding:** The enzyme binds to the thiol-containing substrate, typically a cysteine residue within a protein.
2. **Oxidation of thiol:** The FAD cofactor within the enzyme accepts electrons from the thiol group of the substrate, oxidizing it to a disulfide bond. This oxidation reaction is facilitated by the flavin's ability to cycle between its oxidized and reduced forms.
3. **Electron transfer:** The electrons from the oxidized thiol are transferred to molecular oxygen, which is reduced to water. This step requires the presence of molecular oxygen as an electron acceptor.
4. **Disulfide bond formation:** The oxidized thiol groups of two substrate molecules can then form a disulfide bond, stabilizing the protein structure and influencing its biological activity.

The flavin-dependent sulfhydryl oxidase activity plays a crucial role in various cellular processes, including:

* **Protein folding:** Disulfide bond formation mediated by sulfhydryl oxidases contributes to protein folding and stabilization.
* **Redox signaling:** The oxidation of thiol groups by sulfhydryl oxidases can act as a signaling mechanism in various cellular pathways.
* **Oxidative stress response:** Sulfhydryl oxidases are involved in cellular responses to oxidative stress by oxidizing thiol groups and contributing to redox homeostasis.
* **Extracellular matrix formation:** Sulfhydryl oxidases are essential for the formation and stability of extracellular matrix proteins, which provide structural support and regulate cell adhesion.

Overall, flavin-dependent sulfhydryl oxidase activity is an essential enzymatic function that governs the oxidation of thiol groups within proteins, influencing their structure, function, and cellular interactions.'
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Proteins (1)

ProteinDefinitionTaxonomy
Sulfhydryl oxidase 1A sulfhydryl oxidase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O00391]Homo sapiens (human)

Compounds (1)

CompoundDefinitionClassesRoles
ebselenebselen : A benzoselenazole that is 1,2-benzoselenazol-3-one carrying an additional phenyl substituent at position 2. Acts as a mimic of glutathione peroxidase.benzoselenazoleanti-inflammatory drug;
antibacterial agent;
anticoronaviral agent;
antifungal agent;
antineoplastic agent;
antioxidant;
apoptosis inducer;
EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor;
EC 1.13.11.34 (arachidonate 5-lipoxygenase) inhibitor;
EC 1.3.1.8 [acyl-CoA dehydrogenase (NADP(+))] inhibitor;
EC 1.8.1.12 (trypanothione-disulfide reductase) inhibitor;
EC 2.5.1.7 (UDP-N-acetylglucosamine 1-carboxyvinyltransferase) inhibitor;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor;
EC 3.1.3.25 (inositol-phosphate phosphatase) inhibitor;
EC 3.4.22.69 (SARS coronavirus main proteinase) inhibitor;
EC 3.5.4.1 (cytosine deaminase) inhibitor;
EC 5.1.3.2 (UDP-glucose 4-epimerase) inhibitor;
enzyme mimic;
ferroptosis inhibitor;
genotoxin;
hepatoprotective agent;
neuroprotective agent;
radical scavenger