Straus S D, Fells G A, Wewers M D, Courtney M, Tessier L H, Tolstoshev P, Lecocq J P, Crystal R G
Biochem Biophys Res Commun. 1985 Aug 15;130(3):1177-84. doi: 10.1016/0006-291x(85)91739-5.
alpha 1-antitrypsin (alpha 1AT) deficiency is an inherited disorder almost always associated with the development of panacinar emphysema in the fourth to fifth decades. One source of alpha 1AT for chronic replacement therapy of such individuals is that produced by E.coli directed by a cDNA coding for the human alpha 1AT molecule. Using TG1(E.coli), an alpha 1AT molecule produced by E.coli transformed with the plasmid-expressing vector pTG922, the present study shows that recombinant DNA-directed E.coli-produced alpha 1AT is as an effective inhibitor of neutrophil elastase as alpha 1AT purified from plasma. Importantly, TG1(E.coli) inhibited human neutrophil elastase with an association rate constant of 1.3 +/- 0.4X10(7) M-1 sec-1, similar to that of normal plasma alpha 1AT (1.1 +/- 0.1, p greater than 0.2). Furthermore, when TG1(E.coli) was added to alpha 1AT-deficient plasma obtained from homozygous alpha 1AT type Z individuals, the TG1(E.coli) remained functional and augmented the anti-neutrophil elastase activity of the serum proportional to the amount of TG1(E.coli) added. These observations suggest that if sufficient amounts of recombinant DNA methodology-produced alpha 1AT molecules could be safely delivered to the alveolar structures of alpha 1AT-deficient individuals, they would function to protect the alveolar walls from elastolytic attack.
α1-抗胰蛋白酶（α1AT）缺乏症是一种遗传性疾病，几乎总是与40至50岁时全腺泡型肺气肿的发生相关。对于这类个体进行慢性替代治疗的α1AT的一个来源是由编码人α1AT分子的cDNA指导大肠杆菌产生的。使用TG1（大肠杆菌），即由用表达质粒载体pTG922转化的大肠杆菌产生的α1AT分子，本研究表明，重组DNA指导的大肠杆菌产生的α1AT作为中性粒细胞弹性蛋白酶的抑制剂，其效果与从血浆中纯化的α1AT相同。重要的是，TG1（大肠杆菌）抑制人中性粒细胞弹性蛋白酶的缔合速率常数为1.3±0.4×10⁷ M⁻¹秒⁻¹，与正常血浆α1AT（1.1±0.1，p＞0.2）相似。此外，当将TG1（大肠杆菌）添加到从纯合α1AT Z型个体获得的α1AT缺乏血浆中时，TG1（大肠杆菌）仍保持功能，并按添加的TG1（大肠杆菌）量成比例地增强血清的抗中性粒细胞弹性蛋白酶活性。这些观察结果表明，如果能够将足够量的重组DNA方法产生的α1AT分子安全地递送至α1AT缺乏个体的肺泡结构，它们将起到保护肺泡壁免受弹性蛋白酶攻击的作用。
