is Cystatin C ?
Cystatin C, also named gamma-trace Protein or post-gamma-Globulin,
is a basic inhibitor of cysteine proteases with a molecular mass
of 13359 daltons.
It is produced at a constant rate in all nucleated cells and appears
in human plasma and serum.
cystatin superfamility of inhibitors of papain-like cysteine proteases
amino acid sequences of human Cystatin C was determined in 1981.
Then, it became evident that it belonged to a new superfamily which
now contains 11 members of which Cystatin C is the most well characterized