摘要
目的:对菌株Bacillus sp. L1分泌的胞外蛋白酶EL1进行分离纯化、基因克隆及酶学性质研究。方法:利用硫酸铵沉淀、阴离子交换层析从菌株Bacillus sp. L1的发酵液中分离纯化出胞外酶EL1,对其进行了质谱分析、基因克隆及酶学性质研究。结果:质谱结果提示EL1属于丝氨酸蛋白酶,该酶基因开放阅读框为1326 bp,蛋白序列共441个氨基酸,氨基酸序列与菌株Bacillus stratosphericus分泌的丝氨酸蛋白酶(WP007499449)同源性最高(98%)。该酶最适温度60℃,具有较好的热稳定性;最适pH8.0,在pH8.0时稳定性较好;Mn2+对其有一定的激活作用,Cu2+对其有一定的抑制作用。结论:Bacillus sp. L1分泌的胞外蛋白酶EL1具有较好的热稳定性,在碱溶液中可以保持较高的活力,具有潜在的工业应用价值。
Objective:To study purification,gene cloning and enzymatic properties of extracellular protease secreted by Bacillus sp. L1. Methods:The extracellular protease EL1 was purified by ammonium sulfate precipitation,DEAE sepharose FF and then the enzymatic properties were determined. The extracellular protease EL1 was identified by mass spectrometry(MS). Results:The mass spectrometry results results indicated that the protease EL1 belonged to serine protease. The nucleotide sequence contained 1326 bp,encoding 441 amino acids,which was highly conserved to serine protease of Bacillus stratosphericu(WP007499449)with 98% sequence similarity. The enzymatic properties results suggested that the optimum temperature of EL1 was 60 ℃ and the optimal pH was 8.0.The EL1 was stable and active at 60 ℃ and had a high stability at pH8.0. Mn2+ could activate the activity of EL1 to some extent and Cu2+ could inhibit it to some extent. Conclusion:The extracellular protease EL1 from Bacillus sp. L1 showed a good thermal stability and high stability in alkali sdution,which has potential industrial application value.
作者
李钰娜
宋英达
任晨霞
LI Yu-na;SONG Ying-da;REN Chen-xia(Changzhi Medical College,Changzhi 046000,China)
出处
《食品工业科技》
CAS
北大核心
2020年第5期119-123,共5页
Science and Technology of Food Industry
基金
山西省高等学校科技创新项目(2019L0675)
2018年山西省高等学校大学生创新创业训练项目(2018406)
