鼻分泌物中蛋白抑制酶与螨变应原蛋白酶间的相互作用

目的 研究螨变应原的致敏机理，观察室尘螨变应原蛋白酶与鼻分泌物中蛋白抑制酶在体外的相互作用。方法 鼻分泌物经稀释、混匀、离心后，所得上清液低温保存备用。螨变应原和其它各种蛋白酶分别与各种浓度的水解蛋白抑制酶或不同稀释度的鼻分泌物进行前培养，继而与酶基质进行反应。利用荧光光度计测定被蛋白酶裂解的基质的荧光强度。结果 鼻分泌物中显示出轻工的胰蛋白酶样和其它蛋白酶活性，其能抑制县蛋白酶活性，并对螨变应原

Protease inhibitory activities of nasal secretion on house dust mite allergen]

OBJECTIVE: To elucidate the interaction of protease inhibitors and house dust mite allergen in vitro. METHODS: Nasal secretion was collected by suction from patients with house dust mite nasal allergy, diluted immediately with PBS pH 7.0, mixed with vortex for 10 minutes, and then centrifuged at 2,000 g for 10 minutes. The supernatant was kept at -80 degrees C for use. Synthetic low molecular weight fluorogenic peptide substrates were applied to evaluate protease activities. Crude mite extract and other proteases were used, each of them was preincubated in the presence or absence of nasal fluid or other protease inhibitors at 37 degrees C for 30 minutes. The intensity of fluorescence of aminomethylcoumarin released from the cleaved substrate was measured. RESULTS: Nasal fluid exhibited mild trypsin-like and other protease activities. It inhibited the activities of trypsin and trypsin-like serine proteases and papain-like cysteine proteases in crude mite extract in a dose-dependent manner. CONCLUSIONS: Nasal fluid possibly plays a role in inhibiting penetration of allergen into the nasal mucosa by producing protease inhibitor-protease complex in the nasal mucus layer of patients with mite allergy.