| Type: | Family | Name: | Cystatin |
| Description: | This entry consists of a group of cysteine protease inhibitors. They can be classified as []: Type 1: intracellular cystatins, but may also appear in significant amounts in body fluids []. They are single-chain polypeptides of about 100 residues, which have neither disulphide bonds nor carbohydrate side chains. Type 1 cystatin includes cystatin-A/B. Type 2: extracellular secreted polypeptides synthesised with a 19-28 residue signal peptide. They are broadly distributed and found in most body fluids []. Type 2 cyctatin includes cystatin-C/D/M/F/SA/SN/G. Type 3: multidomain cystatins, including kininogens, known as kinin precursor proteins []. There are three different kininogens in mammals: H- (high molecular mass, ) and L- (low molecular mass) kininogen which are found in a number of species, and T-kininogen that is found only in rat. Unclassified cystatins: cystatin-like proteins. This entry represents the type1, type2 and cystatin-like proteins. | Short Name: | Cystatin |
