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用ＰＣＲ方法从ｐＰＡＩＪ．７中扩增人纤溶酶原激活剂抑制物２型（ＰＡＩ－２）ｃＤＮＡ，与ｐＵＣ１８重组，经限制性内切酶片段分析与核苷酸序列分析，获得全长人ＰＡＩ－２ｃＤＮＡ．ＰＡＩ－２ｃＤＮＡ与原核表达载体重组，构建原核表达质粒并转化大肠杆菌．经温度诱导表达，重组ＰＡＩ－２占全菌总蛋白的１４％，以可溶性形式存在，具纤溶抑制活性．工程菌发酵、压榨后，用硫酸铵分级沉淀，沉淀物经分子筛、离子交换和疏水性色谱的分离，每升菌液可获得约３０ｍｇ纯度达９０％的蛋白质，比活性为１１８６６ＡＩＵ／ｍｇ蛋白质，得率为１９．２％．
PCR method from pPAIJ. 7, human PAI-2 cDNA was amplified, recombined with pUC18, and the full-length human PAI-2 cDNA was obtained by restriction fragment analysis and nucleotide sequence analysis. PAI-2 cDNA was recombined with prokaryotic expression vector to construct prokaryotic expression plasmid and transformed into E.coli. After temperature-induced expression, recombinant PAI-2 accounted for 14% of the total bacterial total protein in soluble form, with fibrinolytic activity. Engineering bacteria fermentation, crushed, the precipitate was fractionated with ammonium sulfate, the precipitate was separated by molecular sieve, ion exchange and hydrophobic chromatography, each liter of bacteria can obtain about 30mg of protein purity of 90%, the specific activity of 11866AIU / mg protein, The yield was 19.2%.