3种蓝细菌藻蓝蛋白β亚基脱辅基蛋白基因的克隆、表达及重组蛋白的抗氧化活性

Cloning,expression and antioxidant activities of apo-c-phycocyanin β-subunits from three cyanobacteria species

为研究蓝细菌藻蓝蛋白脱辅基蛋白的抗氧化活性,分别从3种蓝细菌Spirulina subsalsa、Mastigocladus laminosus和Nostoc PCC 7120中克隆C-藻蓝蛋白β亚基编码基因cpcB_(Sp)、cpcB_(Ma)和cpcB_(No),在大肠杆菌中表达,获得了重组蛋白CpcB_(Sp)、CpcB_(Ma)和CpcB_(No)。通过测定其对羟基自由基和DPPH自由基的清除率,比较它们的抗氧化活性。结果显示:3种重组蛋白对羟基自由基和DPPH自由基的清除率都随着蛋白质质量浓度的增加而升高。当蛋白质浓度达到250 mg/L时,CpcB_(Sp)、CpcB_(Ma)和CpcB_(No)对羟基自由基的清除率分别为82%、89%和93%,对DPPH自由基的清除率分别为43%、49%和58%。以上结果表明,3种重组藻蓝蛋白脱辅基蛋白都具有较高的抗氧化活性,有潜力作为医疗上使用的抗氧化试剂,不同蓝细菌的同源藻蓝蛋白的抗氧化能力存在一定差异,选择不同蓝细菌的藻蓝蛋白是提高重组藻蓝蛋白抗氧化能力的有效途径。

In order to study the antioxidant activity of apo-phycocyanin,the genes(cpcB Sp,cpcB Ma and cpcB No)encoding phycocyanin(C-PC)were cloned from three cyanobacteria species,Spirulina subsalsa,Mastigocladus laminosus and Nostoc PCC 7120.The recombinant proteins,CpcB Sp,CpcB Ma and CpcB No,were obtained from Escherichia coli,where the cpcB Sp,cpcB Ma and cpcB No genes were expressed respectively.The antioxidant capacities of recombinant CpcB Sp,CpcB Ma and CpcB No were evaluated by measuring their hydroxyl radical scavenging activity and DPPH radical scavenging activity.The results showed that the hydroxyl radical and DPPH radical scavenging activity of recombinant proteins increased with the increasing of protein concentration.At a concentration of 250 mg/L,the removal rate of hydroxyl radicals by CpcB Sp,CpcB Ma and CpcB No were 82%,89%and 93%,respectively,whereas CpcB Sp,CpcB Ma and CpcB No exhibited DPPH radicals scavenging activity of 43%,49%and 58%.In conclusion,all three recombinant phycocyanins have high antioxidant activity,and can be used as potent antioxidants in medical treatments.Phycocyanin from different cyanobacteria has some differences in the antioxidant abilities.The choice of C-PC from different algae is an effective way to increase the antioxidant capacities of recombinant phycocyanin.