Analysis of Physicochemical Properties and Structure of Laccase

Laccase is a polyphenol oxidase containing several copper atoms (multicopper oxidase) and has a glycoprotein structure called benzodiazepine[1-3]. This enzyme takes part in the oxidation of a wide range of compounds including mono, di and polyphenols aromatic amines, carboxylic acids and non-phenolic and inorganic substrates. Laccases are used in textile industry, pulp and paper industry, bioremediation and degradation of aromatic compounds including petroleum derivatives[4]. Laccase is produced by various microorganisms such as fungi, bacteria, organic plants and some insects. Laccases are found abundantly in fungal sources, particularly Ascomycetes, Deuteromycetes and Basidiomycota; which are known as white rot fungus[5]. In this study, we selected 20 enzymes from fungal sources to assess physicochemical properties of them. Physicochemical characteristics of the selected enzymes were analyzed using the EXPASY’S Protparam server. In order to analyze the secondary structure and tertiary structure of the enzymes, PSIPRED, Predict Protein and SWISS – Model were used. Furthermore, Phylogenetic tree was constructed for the purpose of analysis the evolutionary relationship using MEGA 7.0 software and the presence of signal peptides was investigated using SignalP server. All investigated laccases except Talaromyces islandicus and Serpula puteana were stable as a value > 40 indicated a stable enzyme. Aliphatic index for laccases produced by Schizophyllum commune and Trametes versicolor were 87.54 and 87.43, respectively, which were among the highest aliphatic indexes. The results of the SignalP server suggested that all laccases possessed signal peptides except Talaromyces islandium

Keywords:

Laccase , ProtParam , Phylogenetic tree , Signal peptide