Comparative characterization of four laccases from Trametes versicolor concerning phenolic C-C coupling and oxidation of PAHs

Publikations-Art

Zeitschriftenbeitrag (peer-reviewed)

Autoren

Koschorreck, K.; Richter, S.M.; Swierczek, A.; Beifuss, U.; Schmid, R.D.; Urlacher, V.B.

Erscheinungsjahr

2008

Veröffentlicht in

Archives of Biochemistry and Biophysics

Verlag

Elsevier

Band/Volume

474/1

DOI

10.1016/j.abb.2008.03.009

Seite (von - bis)

213-219

The laccase genes lcc<b>α</b>, lccb, lccg, and lccd encoding four isoenzymes from <i>Trametes versicolor</i> have been cloned and expressed in Pichia pastoris.  Biochem. characterization allowed classification of these laccases into two distinct groups: Lcca and Lccb possessed higher thermal stability, but lower catalytic activity towards 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) compared to Lccg and Lccd.  Activities of the laccases were quite different as well.  Laccase Lccd showed highest phenolic C-C coupling activity with sinapic acid, but lowest oxidizing activity towards polycyclic arom. hydrocarbons (PAHs).  Highest activity towards PAHs was obsd. with Lccb.  After 72 h, more than 80% of fluorene, anthracene, acenaphthene, and acenaphthylene were oxidized by Lccb in the presence of ABTS.  Investigation of the structural basis of the different activities of the laccases demonstrated the impact of positions 164 and 265 in the substrate binding site on oxidn. of PAHs.