CST4
Function
This protein strongly inhibits papain and ficin, partially inhibits stem bromelain and bovine cathepsin C, but does not inhibit porcine cathepsin B or clostripain. Papain is inhibited non-competitively.
Post-translational modifications
Phosphorylated at both its N- and C-terminal regions.
Sequence Similarities
Belongs to the cystatin family.
Tissue Specificity
Expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). Expressed in saliva, tears, urine and seminal fluid.
Cellular localization
- Secreted
Alternative names
Cystatin-S, Cystatin-4, Cystatin-SA-III, Salivary acidic protein 1, CST4