Siddiqui Ayesha, Kamal Mustafa, Ayatollahi Seyed Abdulmajid, Ali Mohsin, Ahmed Mansoor
Department of Biotechnology, University of Karachi, Karachi-75270, Pakistan.
Phytochemistry Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Iran J Pharm Res. 2017 Summer;16(3):1141-1146.
RM44 was isolated from hot spring near Karachi and screened for the production of extracellular amylase Amy RM44. Amy RM44 was purified to homogeneity on a single step by affinity chromatography using insoluble corn starch. The molecular weight of Amy RM44 was estimated to be 66 kDa by SDS-PAGE and zymographic analysis. Nine fold purification was achieved with the specific activity of 870 U/mg that provides the total yield of the enzyme up to 31%. Studies on purified AmyRM44 characterization revealed that the optimum temperature of enzyme was 100 ºC. Amy RM44 was proved to be highly thermostable as it retained 50% activity after 2 h at 100 ºC. Amy RM44 was stable over wide range of pH with optimum activity at pH 5. Enzyme activity was not significantly inhibited by SDS and EDTA. Amy RM44 also exhibited its activity towards various carbohydrates such as dextrin, pullulan, α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin.
RM44是从卡拉奇附近的温泉中分离出来的，并对其进行筛选以检测细胞外淀粉酶Amy RM44的产生情况。使用不溶性玉米淀粉通过亲和色谱法一步将Amy RM44纯化至同质。通过SDS-PAGE和酶谱分析估计Amy RM44的分子量为66 kDa。实现了9倍的纯化，比活性为870 U/mg，酶的总产率高达31%。对纯化后的AmyRM44特性的研究表明，该酶的最适温度为100℃。Amy RM44被证明具有高度的热稳定性，因为在100℃下2小时后它仍保留50%的活性。Amy RM44在很宽的pH范围内都很稳定，在pH 5时具有最佳活性。酶活性不受SDS和EDTA的显著抑制。Amy RM44对各种碳水化合物如糊精、支链淀粉、α-环糊精、β-环糊精和γ-环糊精也表现出活性。
