{Reference Type}: Journal Article
{Author}: Bleve, Gianluca; Lezzi, Chiara; Spagnolo, Stefano; Tasco, Gianluca; Tufariello, Maria; Casadio, Rita; Mita, Giovanni; Rampino, Patrizia; Grieco, Francesco
{Year}: 2013
{Title}: Role of the C-terminus of Pleurotus eryngii Ery4 laccase in determining enzyme structure, catalytic properties and stabiality
{Tag}: 0
{Star}: 0
{Journal}: PROTEIN ENGINEERING DESIGN & SELECTION
{Volume}: 26
{Issue}: 1
{Pages}: 1-13
{ISBN/ISSN}: 1741-0126
{Keywords}: COMBINATORIAL SATURATION MUTAGENESIS; PRELIMINARY-X-RAY; SACCHAROMYCES-CEREVISIAE; CRYSTAL-STRUCTURE; FUNGAL LACCASE; MELANOCARPUS-ALBOMYCES; MYCELIOPHTHORA THERMOPHILA; SUBCELLULAR-LOCALIZATION; HETEROLOGOUS EXPRESSION; FUNCTIONAL EXPRESSION; C-terminal domain; laccase; rational mutagenesis
{Abstract}: The ERY4 laccase gene of Pleurotus eryngii is not biologically active when expressed in yeast. To explain this finding, we analysed the role of the C-terminus of Ery4 protein by producing a number of its different mutant variants. Two different categories of ERY4 mutant genes were produced and expressed in yeast: (i) mutants carrying C-terminal deletions and (ii) mutants carrying different site-specific mutations at their C-terminus. Investigation of the catalytic properties of the recombinant enzymes indicated that each novel variant acquired different affinities and catalytic activity for various substrates. Our results highlight that C-terminal processing is fundamental for Ery4 laccase enzymatic activities allowing substrate accessibility to the enzyme catalytic core. Apparently, the last 18 amino acids in the C-terminal end of the Ery4 laccase play a critical role in enzyme activity, stability and kinetic and, in particular biochemical and structural data indicate that the K532 residue is fundamental for enzyme activation. These studies shed light on the structure/function relationships of fungal laccases and will enhance the development of biotechnological strategies for the industrial exploitation of these enzymes.
{Author Address}: CNR, ISPA, I-73100 Lecce, Italy; Univ Salento, Dipartimento Sci & Tecnol Biol & Ambientali, I-73100 Lecce, Italy; CNR, ISPA, I-73100 Lecce, Italy; Univ Bologna, Dipartimento Biol Evoluzionist Sperimentale, I-40126 Bologna, Italy; CNR, IMM, I-73100 Lecce, Italy; Univ Bologna, Dipartimento Biol Evoluzionist Sperimentale, I-40126 Bologna, Italy; CNR, ISPA, I-73100 Lecce, Italy; Univ Salento, Dipartimento Sci & Tecnol Biol & Ambientali, I-73100 Lecce, Italy; CNR, ISPA, I-73100 Lecce, Italy
{Database Provider}: Web of Science SCI
{Language}: English
{Country}: Italy; Italy; Italy; Italy

{Reference Type}: Journal Article
{Author}: Makela, Miia R.; Lundell, Taina; Hatakka, Annele; Hilden, Kristiina
{Year}: 2013
{Title}: Effect of copper, nutrient nitrogen, and wood-supplement on the production of lignin-modifying enzymes by the white-rot fungus Phlebia radiata
{Tag}: 0
{Star}: 0
{Journal}: FUNGAL BIOLOGY
{Volume}: 117
{Issue}: 1
{Pages}: 62-70
{ISBN/ISSN}: 1878-6146
{Keywords}: BASIDIOMYCETE PHANEROCHAETE-CHRYSOSPORIUM; MANGANESE PEROXIDASE; LACCASE GENE; CERIPORIOPSIS-SUBVERMISPORA; DEGRADING BASIDIOMYCETE; PLEUROTUS-OSTREATUS; HETEROLOGOUS EXPRESSION; STRUCTURAL-ANALYSIS; MODEL COMPOUNDS; DEGRADATION; Basidiomycete; Laccase; Lignin-modifying peroxidases; White-rot fungi; Wood degradation
{Abstract}: Production of the oxidoreductive lignin-modifying enzymes - lignin and manganese peroxidases (MnPs), and laccase - of the white-rot basidiomycete Phlebia radiata was investigated in semi-solid cultures supplemented with milled grey alder or Norway spruce and charcoal. Concentrations of nutrient nitrogen and Cu-supplement varied also in the cultures. According to extracellular activities, production of both lignin peroxidase (LiP) and MnP was significantly promoted with wood as carbon source, with milled alder (MA) and low nitrogen (LN) resulting with the maximal LiP activities (550 nkat l(-1)) and noticeable levels of MnP (3 mu kat l(-1)). Activities of LiP and MnP were also elevated on high nitrogen (HN) complex medium when supplemented with spruce and charcoal. Maximal laccase activities (22 and 29 mu kat l(-1)) were obtained in extra high nitrogen (eHN) containing defined and complex media supplemented with 1.5 mM Cu2+. However, the nitrogen source, either peptone or ammonium nitrate and asparagine, caused no stimulation on laccase production without Cu-supplement. This is also the first report to demonstrate a new, on high Cu2+ amended medium produced extracellular laccase of P. radiata with pI value of 4.9, thereby complementing our previous findings on gene expression, and cloning of a second laccase of this fungus. (C) 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
{Author Address}: Viikki Bioctr 1, Div Microbiol, Dept Food & Environm Sci, FIN-00014 Helsinki, Finland; Viikki Bioctr 1, Div Microbiol, Dept Food & Environm Sci, FIN-00014 Helsinki, Finland; Viikki Bioctr 1, Div Microbiol, Dept Food & Environm Sci, FIN-00014 Helsinki, Finland; Viikki Bioctr 1, Div Microbiol, Dept Food & Environm Sci, FIN-00014 Helsinki, Finland
{Database Provider}: Web of Science SCI
{Language}: English
{Country}: Finland

{Reference Type}: Journal Article
{Author}: Hariharan, Sudha; Nambisan, Padma
{Year}: 2013
{Title}: Optimization of Lignin Peroxidase, Manganese Peroxidase, and Lac Production from Ganoderma lucidum Under Solid State Fermentation of Pineapple Leaf
{Tag}: 0
{Star}: 0
{Journal}: BIORESOURCES
{Volume}: 8
{Issue}: 1
{Pages}: 250-271
{ISBN/ISSN}: 1930-2126
{Keywords}: RESPONSE-SURFACE METHODOLOGY; PHANEROCHAETE-CHRYSOSPORIUM; PLEUROTUS-OSTREATUS; MODIFYING ENZYMES; AGRO-WASTE; LACCASE; FUNGI; BIOMASS; FIBER; Ganoderma lucidum; Lignin peroxidase; Lignin degradation; Lac; Manganese peroxidase; Pineapple leaf; Solid-state fermentation; Response Surface Methodology; Plackett-Burman Design; Box-Behnken Design
{Abstract}: This study was undertaken to isolate ligninase-producing white-rot fungi for use in the extraction of fibre from pineapple leaf agriwaste. Fifteen fungal strains were isolated from dead tree trunks and leaf litter. Ligninolytic enzymes (lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac)), were produced by solid-state fermentation (SSF) using pineapple leaves as the substrate. Of the isolated strains, the one showing maximum production of ligninolytic enzymes was identified to be Ganoderma lucidum by 18S ribotyping. Single parameter optimization and response surface methodology of different process variables were carried out for enzyme production. Incubation period, agitation, and Tween-80 were identified to be the most significant variables through Plackett-Burman design. These variables were further optimized by Box-Behnken design. The overall maximum yield of ligninolytic enzymes was achieved by experimental analysis under these optimal conditions. Quantitative lignin analysis of pineapple leaves by Klason lignin method showed significant degradation of lignin by Ganoderma lucidum under SSF.
{Author Address}: Cochin Univ Sci & Technol, Plant Biotechnol Lab, Dept Biotechnol, Cochin 682022, Kerala, India; Cochin Univ Sci & Technol, Plant Biotechnol Lab, Dept Biotechnol, Cochin 682022, Kerala, India
{Database Provider}: Web of Science SCI
{Language}: English
{Country}: India