Agrawal Komal, Shankar Jata, Verma Pradeep
Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandarsindari, Kishangarh, Ajmer, 305817 India.
Genomics Laboratory, Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Solan, 173234 Himachal Pradesh India.
3 Biotech. 2020 Sep;10(9):413. doi: 10.1007/s13205-020-02399-8. Epub 2020 Sep 1.
In the present study, specificity of laccase from sp. ITCC-8422 against various substrates, i.e. 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,6-dimethoxyphenol (DMP), guaiacol (GCL) and syringaldazine (SYZ) was determined. It exhibited maximum affinity against ABTS, followed by DMP and negligible activity for GCL and SYZ. As the concentration of substrate increased from 0.5 to 1.5 mM (ABTS) and 1 to 5 mM (DMP), the activity increased from 301.1 to 567.8 U/L and 254.4 to 436.2 U/L. Further, quadrupole time-of-flight liquid chromatography mass spectrometry (QTOF-LCMS) analysis of the extracellular proteome of sp. ITCC-8422 identified eighty-four (84) extracellular proteins. The peptide sequence for the enzyme of interest exhibited sequence similarity with laccase-5 of . Using high molecular mass sequence of laccase-5, the protein structure of laccase was modelled and binding energy of laccase with four substrates, i.e. ABTS (- 5.65), DMP (- 4.65), GCL (- 4.66) and SYZ (- 5.5) was determined using autodock tool. The experimental and in silico analyses revealed maximum activity of laccase and lowest binding energy with ABTS. Besides, laccase was purified and it exhibited 2.1-fold purification with purification yield of 20.4% and had stability of 70% at pH 5-9 and 30-40 ℃. In addition, the bioremediation potential of laccase was explored by in silico analysis, where the binding energy of laccase with alizarin cyanine green was - 6.37 and both in silico work and experimental work were in agreement.
在本研究中,测定了来自sp. ITCC - 8422的漆酶对各种底物的特异性,即2,2 - 联氮 - 双(3 - 乙基苯并噻唑啉 - 6 - 磺酸)(ABTS)、2,6 - 二甲氧基苯酚(DMP)、愈创木酚(GCL)和丁香醛连氮(SYZ)。它对ABTS表现出最大亲和力,其次是DMP,而对GCL和SYZ的活性可忽略不计。随着底物浓度从0.5 mM增加到1.5 mM(ABTS)以及从1 mM增加到5 mM(DMP),活性分别从301.1 U/L增加到567.8 U/L以及从254.4 U/L增加到436.2 U/L。此外,对sp. ITCC - 8422的细胞外蛋白质组进行四极杆飞行时间液相色谱质谱(QTOF - LCMS)分析,鉴定出八十四(84)种细胞外蛋白质。目标酶的肽序列与 的漆酶 - 5表现出序列相似性。利用漆酶 - 5的高分子量序列,对漆酶的蛋白质结构进行建模,并使用自动对接工具测定漆酶与四种底物(即ABTS(-5.65)、DMP(-4.65)、GCL(-4.66)和SYZ(-5.5))的结合能。实验分析和计算机模拟分析均表明漆酶对ABTS具有最大活性和最低结合能。此外,漆酶得到了纯化,纯化倍数为2.1倍,纯化产率为20.4%,在pH 5 - 9和30 - 40℃条件下具有70%的稳定性。此外,通过计算机模拟分析探索了漆酶的生物修复潜力,漆酶与茜素花青绿的结合能为 - 6.37,计算机模拟工作和实验工作结果一致。