乾せん表皮のカリクレイン様酵素

Abstract

Kinin-liberating activities were investigated in scales from the inflammatory skin diseases, psoriasis vulgaris and psoriasis pustulosa, using competitive enzme immunoassay for kinins. Tris-buffered saline extracts of both psoriatic scales liberated the same level of kinins from heated plasma (approximately 11ng/mg protein). In psoriasis vulgaris, three peaks of kinin-liberating activities were shown at Mr 90, 000 (VK-I), 65, 000 (VK-II) and 35, 000 (VK-III) by Sephacryl S-200 gel chromatography. They were further separated by DEAE Sepharose chromatography at pH 7.5. Kinin-liberating activity of VK-I was eluted in nonadsorbed fraction. However, this fraction liberated kinins only from the heated plasma but not from the purified low molecular weight kininogen (LMW-Kng), indicating VK-I is a plasma kallikrein-like enzyme. Kinin-liberating activity of VK-II was separated into two peaks. VK-IIa in nonadsorbed fraction liberated kinins only from the heated plasma, whereas VK-IIb in adsorbed fraction liberated kinins from both heated plasma and LMW-Kng, showing VK-IIa is plasma kallikrein-like and VK-IIb is glandular kallikrein-like. Kinin-liberating activity of VK-III eluted at the same position to VK-IIb, and was found to be glandular kallikrein-like, as well. In psoriasis pustulosa, majority of kinin-liberating activity peaked at Mr 90, 000 by Sephacryl S-200 gel chromatography (PK-I). PK-I demonstrated essentially the same elution profile as VK-I by the following DEAE Sepharose chromatography. VK-I, VK-IIa and PK-I were inactivated by soybean trypsin inhibitor, but only partially by aprotinin, confirming plasma kallikrein-like characteristics. VK-IIb and VK-III were inhibited by aprotintn but not by soybean trypsin inhibitor, confirming glandular kallikrein-like characteristics.