National Institute of Technology Warangal, Warangal 506004, Telangana, India.
National Institute of Technology Warangal, Warangal 506004, Telangana, India.
Enzyme Microb Technol. 2018 Oct;117:32-40. doi: 10.1016/j.enzmictec.2018.06.005. Epub 2018 Jun 18.
Bioactive compounds from endophytes have been used to treat various diseases. In the present study, L-Asparaginase producing endophytes were isolated from Ocimum tenuiflorum (Tulasi) from NIT Warangal, Telangana, India to treat Acute Lymphoblastic Leukemia (ALL) in which L-Asparagine (L-Asn) deamination plays a vital role in ALL treatment. 20 (bacteria and fungi) out of 35 endophytes have been screened for L-Asparaginase production using rapid plate assay technique, in which four strains produced high amounts of L-Asparaginase. 16 s Ribosomal RNA sequencing studies were performed, Bacillus stratosphericus organism was identified, and purified L-Asparaginase sequence has been tailored using MALDI/TOF (Applied Biosystems). The homology model was developed by using MODELLER 9.15v as the endophyte lacks crystal structure of L-Asparaginase enzyme and validated by dint of quality index tools. Docking studies were performed using iGemdock 2.1v. In comparison, free energy binding efficiency of receptor towards L-Asparagine (L-Asn) is good with lesser energy -71.6 kcal/mol in comparison to L-Glutamine (L-Gln) having -67.7 kcal/mol. In order to find the stability of the docked complexes in dynamics environment, molecular dynamics and simulation studies were performed using GROMACS V4.6.5. The trajectory analysis for 10 ns shows the better RMSD, RMSF, Rg and average number of hydrogen bonds for complex 1 (L-Asparaginase + L-Asn docked complex). Hence, complex 1 was found to be more stable than Complex 2 (L-Asparaginase + L-Gln docked complex).
从印度特兰加纳邦的尼赫鲁科技大学（NIT Warangal）的藿香（ Ocimum tenuiflorum ，Tulasi）中分离出具有生物活性化合物的内生菌，用于治疗急性淋巴细胞白血病（ALL），其中 L-天冬酰胺（L-Asn）脱氨酶在 ALL 治疗中起着至关重要的作用。使用快速平板检测技术对 35 种内生菌中的 20 种（细菌和真菌）进行了 L-天冬酰胺酶生产的筛选，其中 4 种菌株产生了大量的 L-天冬酰胺酶。对 16s 核糖体 RNA 测序研究表明，鉴定出的是芽孢杆菌属（ Bacillus stratosphericus ）生物体，并使用 MALDI/TOF（Applied Biosystems）对纯化的 L-天冬酰胺酶序列进行了定制。使用 MODELLER 9.15v 构建同源模型，因为内生菌缺乏 L-天冬酰胺酶的晶体结构，并通过质量指标工具进行了验证。使用 iGemdock 2.1v 进行对接研究。相比之下，受体与 L-天冬酰胺（L-Asn）的结合自由能效率更好，为-71.6 kcal/mol，而与 L-谷氨酰胺（L-Gln）的结合自由能效率为-67.7 kcal/mol。为了在动力学环境中找到对接复合物的稳定性，使用 GROMACS V4.6.5 进行了分子动力学和模拟研究。10 ns 的轨迹分析表明，复合物 1（L-天冬酰胺酶+L-Asn 对接复合物）的 RMSD、RMSF、Rg 和平均氢键数量更好。因此，复合物 1 比复合物 2（L-天冬酰胺酶+L-Gln 对接复合物）更稳定。
