Multicopper oxidase laccases with distinguished spectral properties: A new outlook

Multicopper oxidases (MCOs) has a unique feature of having the presence of four Cu atoms arranged into three (Type I, II and III) spectral classification. MCOs laccase due to its broad range of substrate specificity has numerous biotechnological applications. The two types of laccases include the typical blue and the atypical white, yellow laccases which have been isolated from diverse geographical locations globally. In the present study laccases were identified using Liquid Chromatograph Mass Spectrometer Studies (LCMS) study where blue laccase exhibited homology with Trametes villosa Q99044 and Q99046 and white, yellow laccase exhibited homology with Myrothecium verrucaria OX = 1859699; Q12737 and Trametes versicolor Q12717 respectively. The spectral comparison between laccases were determined via spectroscopic analysis where UV-spectra of blue laccase from Trametes versicolor had a peak at 605 nm (Type I Cu atom) whereas in case of white and yellow laccases the peak was absent and in addition had an absorption peak at 400nm. It was followed by X-Ray Diffraction (XRD) analysis of proteins where α-helix (10°) and β-sheet (22°) structure were observed in case of all the three laccases. However, the intensity of α-helix in white and yellow laccase was stronger as compared to the blue laccase whereas the intensity of β-sheet was stronger in case of blue laccase as compared to other two laccases. Further, Fourier-transform infrared spectroscopy (FTIR) analysis was performed which enabled the analysis of proteins where α-helix (1650-1658 cm^-1), β-sheets (1620-1640 cm^-1), amide I (1700-1600 cm^-1) amide II (bands at under 1400 cm^-1) and amide A, B (bands above 3000 cm^-1).