Aim To optimize purification conditions of recombinant hirudin 3 in thefermentation broth and characterize the product. Methods Reambinant hirudin 3 was isolated andpurified from the fermentation broth by three column chromatography steps with macroporous resin,DEAE cellulose DES2 and preparative RP-HPLC, respectively, and the optimal conditions were obtained.Purity of the product was determined by SDS-PAGE and analytical RP-HPLC. The molecular weight wasdetermined by mass spec-trometry. The structure of the product was analyzed by peptide map.ResultsThe product with purity of 95.4786% was obtained after three purification steps in the optimumconditions with a total yield of 39%. The molecular weight of the product was 6 913.32 ± 6.55 Da,coincident to the theoretical molecular weight of r-hirudin 3. The structure of the product wascoincident to r-hirudin 3 either. Conclusion The optimized purification steps can be successfullyemployed for purification of r-hirudin 3 from E. coli using batch-type approaches. The productobtained with high purity was confirmed to be r-hirudin 3.
Aim To investigate the anticancer activity of two new cytotoxins from thevenom of Agkistrodon acutus. Methods The venom was isolated by FPLC column chromatography consistingof DEAE Sepharose FF and Source 30S. The cytotoxic activity on tumor cells was detected by MITmethod. Purity and molecular weight were determined by SDS-PAGE (silver staining). Their stabilitiesto temperature and pH were also detected. Results Two pure cytotoxins named ACTX-6 and ACTX-8 wereobtained. Their molecular weights are 98 kDa and 27 kDa, respectively. ACTX-6 consists of twosubunits bonded together by disulfide bonds. Conclusion ACTX-6 and ATCX-8 have highest inhibitoryactivity on lung cancer cell A549. ACTX-6 is stable to heat while ACTX-8 not. ACTX-6 is stablebetween pH 7-9 and ACTX-8 between pH 6 - 9.
通过测定重组水蛭素Ⅲ的质粒中目的基因序列、重组水蛭素Ⅲ分子质量、C末端序列以及菌体蛋白和DNA残留量,对重组水蛭素Ⅲ的质量进行研究。结果:重组质粒经NheⅠ、HindⅢ双酶切和基因序列测定,表明工程菌所携带的质粒上含有完整的信号肽基因、NheⅠ酶切位点、水蛭素HV3基因和HindⅢ酶切位点;还原性SDS PAGE结果表明在14 000 u处有单一条带,为重组水蛭素Ⅲ二聚体;测定样品分子C端序列为E D YA D E P I P E F,与重组水蛭素Ⅲ的理论值一致;重组水蛭素Ⅲ样品中的残留菌体蛋白和DNA含量分别是0.02%和每剂量样品中残留DNA含量低于2.8 ng。结论:从基因水平、蛋白水平和杂质的角度证明重组水蛭素Ⅲ产品符合质量控制标准。
