探索表达于大肠杆菌中的抗凝溶栓双功能水蛭素12肽和瑞替普酶融合蛋白(The fusion protein of 12 peptide of hirudin and reteplase,HV12p-rPA)的体外复性方法。采用直接透析复性和氧化复性结合透析复性两种方式,并分析复性时间、温度、适宜的氧化-还原体系比例对复性率的影响。分别测定其体外抗凝活性和纤溶活性,确定复性效果。结果显示:将变性溶解的HV12p-rPA在含8mol/L脲,0.05mmol/LGSSG,0.7mol/LL-Arg的50mmol/LGly-NaOH(pH9.20)缓冲液中于25℃氧化复性6h后,再在含0.5mol/LL-Arg,1mmol/L胱氨酸,2mmol/L半胱氨酸的20mmol/LGly-NaOH(pH9.20)缓冲液中于4℃进行梯度脲浓度透析,每隔8h换液一次,透析48h,可获得具有抗凝活性为730ATU/mg,纤溶活性为19768IU/mg的可溶性蛋白质。
Utilization of carbon dioxide(CO_(2))has become a crucial and anticipated solution to address environmental and ecological issues.Enzymes such as carbonic anhydrase(CA)can efficiently convert CO_(2) into various platform chemicals under ambient conditions,which offers a promising way for CO_(2) utilization.Herein,we constructed a Pickering interfacial biocatalytic system(PIBS)stabilized by CA‐embedded MOFs(ZIF‐8 and ZIF‐L)for CO_(2) mineralization.Through structure engineering of MOFs and incorporation of Pickering emulsion,the internal and external diffusion processes of CO_(2) during the enzymatic mineralization were greatly intensified.When CO_(2) was ventilated at a flow rate of 50 mL min^(–1) for 1 h,the pH value of PIBS dropped from~8.00 to~6.50,while the average pH value of free system only dropped to~7.15,indicating that the initial reaction rate of CO_(2) mineralization of PIBS is nearly twice that of the free system.After the 8^(th) cycle reaction,PIBS can still produce more than 9.8 mg of CaCO_(3) in 5 min,realizing efficient and continuous mineralization of CO_(2).
Boyu ZhangJiafu ShiYang Zhao aHan WangZiyi ChuYu ChenZhenhua WuZhongyi Jiang
