The gene encoding the mature peptide was cloned from the total rna of h rhossiliensis owvt1 by rtpcr . sequence analysis of the gene was described in this papel the amino acid sequence , as derived from the nucleotide sequence of a cdna clone , had high homology with other subtilisin - like serine protease of nematogenous fimgi 与其他丝氨酸蛋白酶基因序列比较表明，与其他线虫卵寄生性真菌如paecilomyceslilacinus 、 verticilliumchlamydosporium及m . anisopliaevar . anisopliae同源性较高，而与捕食线虫真菌arthrobotrysoligospora同源性较低( 45 ) 。
Dna sequence analysis showed that the cloned nk gene was highly homologous to the sequence reported by nakamura . the deduced amino acid sequence also had the conserved sequences ( serine 221 , histidine 64 , and aspartic acid 32 ) which was essential for the catalytic center of serine proteases . the nk gene was then cloned into the transfer vector pvl1393 本实验以b . subtilis ( natto )基因组dna为模板扩增了nk基因，测序结果显示与nakamura报道的纳豆激酶基因高度同源，其氨基酸序列也含有丝氨酸蛋白酶的活性保守中心( serine221 ， histidine64 ， asparticacid32 ) 。
Based on the extensive studies of subtilisin - like protease ( prl ) of metarhizium anisopliae , extracellullar serine protease is suggested to be a key enzyme involved in the fimgal penetration to invertebrates . the investigation of serine protease in the nematode infected by owvtl may help to understand the mechanism of nematophagous fimgi as biological control agents . a 3l kda serine protease was isolated and purified from the liquid culture of h rhossiliensis owvtl challenged with nematode panagrellus redivivus 本研究利用线虫诱导下owvt - 1菌株液体发酵，通过粗分级分离、离子交换层析和凝胶过滤层析分离提纯了一个分子量为31kda的丝氨酸蛋白酶，生物学测定表明其对大豆胞囊线虫二龄幼虫具有致死作用，同时测定了该酶理化特性，酶活力在75附近酶活力最高，随着ph的增加酶的稳定性升高，与胆碱酯酶具有相似的ph曲线，对特异性底物aape ( suc - ala - ala - pro - glu - pna )具有作用， ssi和ci - 2抑制该酶的活性。
