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Cystatin
Group of endogenous cysteine proteinase inhibitors / From Wikipedia, the free encyclopedia
The cystatins are a family of cysteine protease inhibitors which share a sequence homology and a common tertiary structure of an alpha helix lying on top of an anti-parallel beta sheet. The family is subdivided as described below.
Quick Facts Proteinase inhibitor I25, cystatin, Identifiers ...
Proteinase inhibitor I25, cystatin | |||||||||||
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![]() Crystal structure of an immunomodulatory salivary cystatin from the soft tick Ornithodoros moubata from PDB entry 3L0R.[1] | |||||||||||
Identifiers | |||||||||||
Symbol | Prot_inh_cystat | ||||||||||
Pfam | PF00031 | ||||||||||
Pfam clan | CL0121 | ||||||||||
InterPro | IPR000010 | ||||||||||
SMART | SM00043 | ||||||||||
PROSITE | PDOC00259 | ||||||||||
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Cystatins show similarity to fetuins, kininogens, histidine-rich glycoproteins and cystatin-related proteins.[2][3][4] Cystatins mainly inhibit peptidase enzymes (another term for proteases) belonging to peptidase families C1 (papain family) and C13 (legumain family). They are known to mis-fold to form amyloid deposits and are implicated in several diseases.[citation needed]