cystatin 1 (cystatin-SN, salivary cystatin-SA-1, CST1)

Function: - one of several cysteine proteinase inhibitors immunologically related to cystatin S - cystatin SN, with a pI of 7.5, is a much better inhibitor of papain & dipeptidyl peptidase-1 than is cystatin S - both inhibit ficin equally well Structure: belongs to the cystatin family Compartment: secreted Expression: found in saliva, tears, urine & seminal fluid

Properties

SIZE: entity length = 141 aa MW = 16 kD COMPARTMENT: saliva semen tears MOTIF: signal sequence {1-20} glycine residue {32} Secondary area of contact {76-80} cysteine residue {C94} MODIFICATION: cysteine residue {C104} cysteine residue {C104} MODIFICATION: cysteine residue {C94} cysteine residue {C118} MODIFICATION: cysteine residue {C138} cysteine residue {C138} MODIFICATION: cysteine residue {C118} INHIBITS: cysteine proteinase

Database Correlations

OMIM 123855 UniProt P01037 Pfam PF00031 Entrez Gene 1469 Kegg hsa:1469