title: Molecular and enzymatic characterisation of extra- and intracellular laccases from the acidophilic ascomycete Hortaea acidophila.
abstract: The pigmented ascomycete Hortaea acidophila is able to grow at a pH as low as 0.6 and produces laccases that are involved in melanin synthesis. We now present data on an extracellular and an intracellular laccase which exhibit a high stability at low pH. Furthermore, the optimum for enzyme acitivity is extraordinarily low with pH 1.5 for the intracellular laccase with 2,6-dimethoxyphenol (DMOP) as substrate. Two complete laccase gene sequences of H. acidophila were amplified by inverse polymerase chain reaction (PCR). Whereas the deduced protein laccase I contains an predicted N-terminal signal sequence for protein export, laccase II does not and thus may represent the intracellular laccase. The acidophilic character of both laccases seems to be reflected in their primary structure.
authors.affiliation: Institut für Zelluläre und Molekulare Botanik, Rheinische Friedrich-Wilhelms-Universität, Kirschallee 1, Bonn, Germany.
authors.forename: Larissa
authors.initials: L
authors.lastname: Tetsch
authors.forename: Jutta
authors.initials: J
authors.lastname: Bend
authors.forename: Udo
authors.initials: U
authors.lastname: Hölker
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology*; D001483:Base Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D005800:Genes, Fungal; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D042845:Laccase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D021382:Protein Sorting Signals / Q000235:genetics; D011748:Pyrogallol / Q000031:analogs & derivatives / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D021382:Protein Sorting Signals; D011748:Pyrogallol; C010120:pyrogallol 1,3-dimethyl ether; D042845:Laccase