OSCN- reacts with Cys residues

Stable Identifier
R-HSA-8941411
Type
Reaction [transition]
Species
Homo sapiens
Compartment
Locations in the PathwayBrowser
General
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout

The reaction of hypothiocyanite (OSCN(-)) with cysteine-derived sulfhydryl groups produces sulfenyl thiocyanates (Cys-S-SCN) which in turn may form disulfides or sulfenic acids (Cys-SOH) that can then be repaired through enzymatic mechanisms (Skaff O et al. 2009; Nagy P et al. 2009; Trujillo M et a. 2015). OSCN(-) is produced by two-electron oxidation of thiocyanate (SCN(-)) in the presence of hydrogen peroxide (H2O2) (Furtmüller PG et al. 2006; Ashby MT 2008). SCN(-) oxidation is catalyzed by defensive human peroxidases, myeloperoxidase (MPO) and lactoperoxidase (LPO), occurring in human secretory mucosa, including the oral cavity, airway, and alimentary tract (Ihalin R et al. 2006; Furtmüller PG et al. 2006; Ashby MT 2008). The OSCN(-) is the conjugate base of hypothiocyanous acid (HOSCN). Both OSCN(-) and HOSCN are potent antimicrobial species that kill invading pathogens. OSCN(-)/HOSCN are thought to oxidize sulphydryls of essential proteins of a microorganism, resulting in an alteration in its cellular functions and thus regulating resident and transient flora in human secretory mucosa as part of innate immunity (Hoogendoorn H et al. 1977; Thomas EL & Aune TM 1978; Mickelson MN 1979; Hawkins CL 2009). OSCN(-)/HOSCN have been viewed as mild oxidants, which are better tolerated by host tissue (Chandler JD et al.2013; Chandler JD & Day BJ 2012). However, HOSCN may target specific thiol-containing cellular proteins resulting n the initiation of significant cellular damage (Barrett TJ & Hawkins CL 2012).

Literature References
Participants
Participant Of
Authored
Reviewed
Created