A protease-like permeability factor in the guinea pig skin 1. Patial purification and characterization

A permeability factor was extracted in a latent from from guinea pig skin and separated by ammonium fraction into the pseudoglobulin fraction (30–50% saturation). The activation of the latent form of t he permeability factor seemed to be caused in the desalting step by gel filtration with Sephadex G-50. The factor was partially purified by streptomycin treatment and column chromatography using hydroxyapatite, diethylaminoethyl cellulose and Sephadex G-75, in this order. Gel filtration showed that its molecular weight was approx. 35 000. Its permeability activity was heat stable at 61δC for 60 min at neutral pH, resistant at pH 5–10 and at ionic strengts from deionized water to 1 M NaCl at 4°C. Its activity was transient and suppressed by guneia pig serum, but insensitive to an anti-histamic agent (triprolidine). Furthermore, its permeability activity was inhibited by diisopropylfluorophosphate, soybean trypin inhibitor and leupeptin, and completely adsorbed by soybean trypsin inhibitor affinity column. These findings suggested that the permeability factor was a ser ine-type protease.