短小芽孢杆菌中果胶裂解酶BpPL1的异源表达及酶学性质研究

Heterologous Expression and Enzymatic Properties ofPectin Lyase BpPL1 from Bacillus breve

果胶裂解酶是一类通过β-消除机制降解果胶的裂解酶,对果胶降解及修饰具有重要意义。利用基因工程技术,从短小芽孢杆菌中异源表达了一种新的果胶裂解酶BpPL1,并对其进行酶学性质和功能研究。结果表明,纯化后BpPL1的蛋白质量浓度和比活力分别为0.24 mg/mL和164.61 U/mg,最适pH值和温度为9.5和50℃;此外,浓度为5 mmol/L的Ca2+溶液能够有效地提高BpPL1的酶活力至原来的147.2%。利用橘皮果胶为底物,BpPL1可将其部分降解为寡糖,此研究结果有利于实现果胶的降解和寡糖的制备。

Pectin lyase is a kind of lyase that degrades pectin through theβ-elimination mechanism,which is of great significance for pectin degradation and modification.In this study,a novel pectin lyase BpPL1 was heterologous expressed from Bacillus breve by genetic engineering technology,and its enzymatic properties and functions were studied further.The results showed that the protein concentration and specific activity of BpPL1 were 0.24 mg/mL and 164.61 U/mg,respectively.And the optimal pH and temperature were 9.5 and 50℃.In addition,5 mmol/L Ca2+could effectively increase the enzyme activity of BpPL1 to 147.2%.Using peel pectin as a substrate,BpPL1 could partially degrade it to produce oligosaccharides.The results in this study were conducive to the degradation of pectin and the preparation of oligosaccharides.