Stepanova E V, Fedorova T V, Sorokina O N, Volkov V V, Koroleva O V, Dembo A T
Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
Biochemistry (Mosc). 2009 Apr;74(4):385-92. doi: 10.1134/s0006297909040051.
The effect of solvent phase transitions on catalytic activity and structure of the active site of laccase produced by the Basidiomycetes Coriolus hirsutus 072 was studied. As shown by small-angle X-ray scattering, laccase exists in solution as a mixture of monomeric and aggregated particles in the percent ratio 85:15. This ratio did not change on phase transitions. A complex nature of laccase activity dynamics during thawing and further heating to 20 degrees C was shown. Spontaneous oxidation of T1 copper center in the temperature range 12-20 degrees C was not observed. According to spectral data, the structure of laccase active sites including all copper centers of types T1, T2, and T3 changes during the phase transition.
