Cystatin A （acid cysteine proteinase inhibitor，ACPI） is a natural inhibitor of cysteine proteinases and is located mainly in the keratohyaline granules of the stratum granulosum and the cornified envelope of the stratum corneum in the epidermis. Human cystatin A consists of 98 amino acid residues and belongs to cystatin subfamily I （stefins）. Among the target enzymes inhibited by cystatin A are cathepsins B，C，H，L，and S，papain and actinidin. Cystatin A has also been detected in infiltrative breast carcinoma.
应用类型
Western blotting （1-4 ug/ml） and Immunohistochemistry. However， the optimal conditions should be determined individually. Recognizes human cystatin A. Does not cross-react with cystatin B.
