Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Azadi sq., Mashhad, Iran.
Int J Biol Macromol. 2010 Apr 1;46(3):289-97. doi: 10.1016/j.ijbiomac.2010.01.013. Epub 2010 Jan 28.
This paper describes the purification and characterization of a novel acidophile alpha-amylase from newly isolated Bacillus sp. Ferdowsicous. The enzyme displayed a molecular weight of 53 kDa and it was stable over a range of pH from 3.5 to 7 with an optimum around 4.5. The optimum temperature for activity was found to be around 70 degrees C and the enzyme remained active to more than 75% up to 75 degrees C for 45 min. The enzyme activity was decreased by Zn(2+)and EDTA but inhibited by Hg(2+), whereas the activity was increased by approximately 15% by Ba(2+) and Fe(2+). Na(+), Mg(2+), K(+), Ca(2+), PMSF, Triton X-100 and beta-mercaptoethanol had any considerable effect on its activity. The enzyme activity on the amylose as substrate was 1.98 times greater than amylopectin. Partial N-terminal sequencing demonstrated no significant similarity with other known alpha-amylases, indicating that the presented enzyme was new. Considering its promising properties, this enzyme can find potential applications in the food industry as well as in laundry detergents.
本文描述了一种新型嗜酸 α-淀粉酶的纯化和特性，该酶来自新分离的巴氏芽孢杆菌。该酶的分子量为 53 kDa，在 pH 3.5 到 7 的范围内稳定，最适 pH 值约为 4.5。该酶的最适温度约为 70°C，在 75°C 下保持活性超过 75%，持续 45 分钟。Zn(2+)和 EDTA 会降低酶活性，但 Hg(2+)会抑制酶活性，而 Ba(2+)和 Fe(2+)则会使酶活性增加约 15%。Na(+)、Mg(2+)、K(+)、Ca(2+)、PMSF、Triton X-100 和 β-巯基乙醇对其活性没有显著影响。该酶对直链淀粉作为底物的活性是支链淀粉的 1.98 倍。部分 N-末端测序表明，与其他已知的 α-淀粉酶没有显著相似性，表明该酶是新的。考虑到其有前景的性质，这种酶在食品工业以及洗衣洗涤剂中可能有潜在的应用。
