A 43-kDa papain inhibitor produced by a cultured human epidermal cell line.

Epidermis-derived cells (NCTC 2544) were cultured and the proteins of the culture medium, as well as of the cells, were fractionated by gel-chromatography. The fractions were analyzed for their papain-inhibitory capacity and for the presence of so-called 43-kDa papain inhibitor. A papain inhibitor was identified with molecular weight and immunological characteristics similar to the original 43-kDa inhibitor that was isolated from psoriatic scales. The result proves that NCTC-2544 cells can produce the so-called psoriasis inhibitor under culture conditions.