Proteases Associated with Arthus Skin Lesions: Their Purification and Biological Significance (Preliminary Report)

Abstract

The SH-dependent proteases (I and II) responsible for the development of Arthus hypersensitivity reaction were extracted in the euglobulin fraction of the skin lesions, and highly purified by column chromatography using Sephadex G-50, DEAE-Sephadex A-50 and GE-cellulose in this order. They behaved each as an almost homogeneous substance on electrophoresis. The optimum pH of these proteases was 7.1, which was a pH value adequate for their action in the Arthus skin site. They were different from cathepsins D and E. Intradermal injections of these SH-dependent proteases (I and II) induced rapid development of local cutaneous lesions similar to those of the Arthus skin lesions in both gross and microscopic features.
On the other hand, another SH-independent protease was also isolated from the Arthus skin lesions, but it was ineffective in causing inflammatory reaction on experimental injection; this SH-independent protease may not play a significant part for the development of Arthus reaction.