Arjun Jaya Kumar, Aneesh Balakrishna Pillai, Kavitha Thulasi, Harikrishnan Kumarapillai
Environmental Biology Lab, Department of Biotechnology, Government of India, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O. Poojappura, Thiruvananthapuram, Kerala, 695014, India.
Biotechnol Lett. 2018 Feb;40(2):343-348. doi: 10.1007/s10529-017-2470-7. Epub 2017 Nov 10.
To screen soil metagenomic libraries for novel enzymes with enhanced activities.
To screen soil metagenomic libraries for novel enzymes with enhanced activities. A novel L-asparaginase was identified from forest soil metagenome and its characteristics were studied. The purified protein had a specific activity of 696 IU mg and optimum activity at pH 7 and 35 °C. Enhanced enzyme activities were observed in the presence of Mg, Ca and K. The K value, 2 mM, and enzyme specificity constant 7.7 mMs indicated that the recombinant enzyme has good substrate affinity to L-asparagine compared with commercially-available Escherichia coli asparaginase. The IC value of 0.78 µg ml (0.47 IU ml) was observed with HL60 cell line and 0.39 µg ml(0.23 IU ml) with MOLT-3 and MOLT-4 cell lines, which is better than that of commercially-available drugs.
The soil metagenome derived L-asparaginase with enhanced activities could be a potential candidate to develop as a drug in Acute Lymphoblastic Leukemia (ALL) therapy.
筛选具有增强活性的新型酶的土壤宏基因组文库。
筛选具有增强活性的新型酶的土壤宏基因组文库。从森林土壤宏基因组中鉴定出一种新型L-天冬酰胺酶并对其特性进行了研究。纯化后的蛋白质比活性为696 IU/mg，在pH 7和35℃时具有最佳活性。在Mg、Ca和K存在的情况下观察到酶活性增强。K值为2 mM，酶特异性常数为7.7 mM/s，表明与市售大肠杆菌天冬酰胺酶相比，重组酶对L-天冬酰胺具有良好的底物亲和力。HL60细胞系的IC值为0.78 μg/ml（0.47 IU/ml），MOLT-3和MOLT-4细胞系的IC值为0.39 μg/ml（0.23 IU/ml），优于市售药物。
土壤宏基因组来源的具有增强活性的L-天冬酰胺酶可能是急性淋巴细胞白血病（ALL）治疗中开发药物的潜在候选物。
