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Heterologous expression and characterization of a high redox potential laccase from Coriolopsis polyzona MUCL 38443

In this study, a novel laccase gene, named as Cplcc1, and its corresponding cDNA were isolated and characterized from the Coriolopsis polyzona MUCL 38443 strain. The Cplcc1 gene consists of a 1563-bp open reading frame encoding a protein of 520 amino acids with a 20-residue putative signal peptide. | Turkish Journal of Biology Turk J Biol (2017) 41: 278-291 © TÜBİTAK doi:10.3906/biy-1605-51 http://journals.tubitak.gov.tr/biology/ Research Article Heterologous expression and characterization of a high redox potential laccase from Coriolopsis polyzona MUCL 38443 1,2 3 1, Orkun PİNAR , Candan TAMERLER , Ayten YAZGAN KARATAŞ * Department of Molecular Biology and Genetics, Molecular Biology-Biotechnology and Genetics Research Center (MOBGAM), İstanbul Technical University, İstanbul, Turkey 2 Department of Bioengineering, Faculty of Engineering, Marmara University, İstanbul, Turkey 3 Bioengineering Research Center and Department of Mechanical Engineering, University of Kansas, Lawrence, Kansas, USA 1 Received: 18.05.2016 Accepted/Published Online: 21.10.2016 Final Version: 20.04.2017 Abstract: In this study, a novel laccase gene, named as Cplcc1, and its corresponding cDNA were isolated and characterized from the Coriolopsis polyzona MUCL 38443 strain. The Cplcc1 gene consists of a 1563-bp open reading frame encoding a protein of 520 amino acids with a 20-residue putative signal peptide. The size of the Cplcc1 gene is 2106 bp and it contains ten introns and five potential N-glycosylation sites. Additionally, the isolated full-length Cplcc1 cDNA was successfully expressed in Pichia pastoris. The heterologous expression conditions were also optimized and the highest activity value increased to 800 U L–1 with 1.5% methanol, 0.8 mM CuSO4, and 0.6% L-alanine supplementation. The recombinant laccase was partially purified and the molecular weight was found as approximately 54 kDa. The maximum oxidation activity was observed for 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) at pH 3.0. The optimal temperature was found as 70 °C. On the other hand, at 30 °C, the enzyme was stable for more than a week and its half-life was longer than 8 h. The Km, Vmax, kcat, and kcat Km–1 values of the recombinant laccase were identified as 0.137 mM, 288.6 µmol .