... domain-swapping in the cystatin family[20]. Although both additional cysteines in cystatin Fat positions 1 and 37 (cystatin C numbering) can forma disulfide bond [13], the cysteine at position ... regulating papain-like cathepsins involved in antigen presentation. Therefore, interactions of cystatin F with severalof its potential targets, cathepsins F, K, V, S, H, X and C, were studied in ... cathep-sins C and X were not inhibited by cystatin F. In order to investigate thebiological significance of the inhibition data, the intracellular localizationof cystatin F and its potential...