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Properties and nature of a cysteine proteinase inhibitor located in keratohyalin granules of rat epidermis
Author(s) -
Takahashi Masae,
Tezuka Tadashi,
Towatari Takae,
Katunuma Nobuhiko
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80940-k
Subject(s) - cystatin , epidermis (zoology) , polyclonal antibodies , microbiology and biotechnology , papain , chemistry , isoelectric point , biochemistry , cysteine , cysteine proteinase inhibitors , cystatin c , biology , antibody , enzyme , apoptosis , programmed cell death , renal function , caspase , immunology , anatomy
The p I 4.7, 14.5 kDa hematoxylin‐stainable protein (HSP) from rat epidermis inhibited the activities of the cysteine proteinases papain, ficin, cathepsins B, H and L with similar inhibitory characteristics as recombinant cystatin‐α. Proteinases of other classes were not inhibited. The inhibitory activity of HSP was heat stable in the wide pH range of 3.0–10.0. Polyclonal antibodies against HSP cross‐reacted with cystatin‐α and the molecular mass of HSP was similar to that of cystatin‐α, though its isoelectric point was different. The in vivo location of both HSP and cystatin‐α is on keratohyalin granules in epidermis as detected by indirect immunofluorescence technique using individual antibodies. Therefore it is highly probable that HSP is a cystatin‐α derivative or a very similar proteinase inhibitor belonging to a family of cystatins.