| 摘要 |
Purification of plasminogen activator inhibitor 2 (I) comprises (1) pre-incubating (I)-contg. soln. with an agent (A) for splitting disulphide bridges (2) treating with a water-soluble acridine or quinoline base (pref. 2-ethoxy-6,9-diaminoacridine lactate (II)) so that the ppte. formed contains little or no (I), (3) sepn. of this ppte. and (4) recovery of (I) from the supernatant and opt. further purification by known methods. (A) is pref. dithiothreitol (DTT) used at a concn. of 10-250 (pref. 100) mM, and preincubation is for 0.25-3 (esp. 1) hr. at 10-40 (pref. 37 deg.C). The starting soln. is pref. placental extract or contains (I) made by recombinant DNA methods, and after incubation with DTT is treated with (II) at 0.2-2g/g protein in soln. at pH 5.5-8.5. The resulting supernatant (which contains 85-90% of the (I) but only 5-8% of total proteins) can be treated with 5% NaCl to salt out (II), then subjected to pptn. with (NH4) S04 (a) at 30% satn. to remove more impurities and (b) at 80% satn. to recover (I). (I) is used therapeutically to regulate the fibrinolytic system. Compared with known methods for purifying (I) (which involve 8 stages) this process is simpler and is suitable for large scale operation. The base pptes. impurities while (I) remains in soln. |
