Cys112

Cys112 refers to the cysteine residue at position 112 in a protein sequence. The numbering is protein-specific and can vary with alternative splicing, processing, or different species, so Cys112 in one protein may correspond to a different contextual position in another.

Cysteine side chains are versatile in biology because of their thiol group. Cys112 may participate in catalysis as a nucleophile, contribute to redox regulation through reversible oxidation to sulfenic, sulfinic, or sulfonic acids, or form intramolecular or interprotein disulfide bonds. It can also coordinate metal ions in some metalloproteins, or serve as a site for post-translational modification such as nitrosylation or glutathionylation. The actual role of Cys112 is determined by the local structure, solvent exposure, pKa, and neighboring residues.

In experimental studies, Cys112 is often probed by mutagenesis (for example, C112A or C112S) to assess its contribution to activity, stability, or regulation. Structural data from X-ray crystallography or NMR, and redox proteomics can reveal whether Cys112 is engaged in metal binding, disulfide formation, or redox signaling. Conservation of Cys112 across orthologs can indicate functional importance, while lack of conservation suggests a permissive or context-dependent role.