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Latent and active abPPO4 mushroom tyrosinase cocrystallized with hexatungstotellurate(VI) in a single crystal

DOI: 10.1107/S1399004714013777 DOI Help
PMID: 25195745 PMID Help

Authors: Stephan Mauracher (Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien) , Christian Molitor (Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien) , Rami Al-oweini (School of Engineering and Science, Jacobs University) , Ulrich Kortz (School of Engineering and Science, Jacobs University) , Annette Rompel (Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acta Crystallographica Section D Biological Crystallography , VOL 70 , PAGES 2301 - 2315

State: Published (Approved)
Published: September 2014
Diamond Proposal Number(s): 8476

Open Access Open Access

Abstract: Tyrosinases, bifunctional metalloenzymes, catalyze the oxidation of monophenols and o-diphenols to o-quinones, the precursor compounds of the brown-coloured pigment melanin. In eukaryotic organisms, tyrosinases are expressed as latent zymogens that have to be proteolytically cleaved in order to form highly active enzymes. This activation mechanism, known as the tyrosinase maturation process, has scientific and industrial significance with respect to biochemical and technical applications of the enzyme. Here, not only the first crystal structure of the mushroom tyrosinase abPPO4 is presented in its active form (Ser2-Ser383) and in its 21 kDa heavier latent form (Ser2-Thr545), but furthermore the simultaneous presence of both forms within one single-crystal structure is shown. This allows for a simple approach to investigate the transition between these two forms. Isoform abPPO4 was isolated and extensively purified from the natural source (Agaricus bisporus), which contains a total of six polyphenol oxidases (PPOs). The enzyme formed crystals (diffracting to a resolution of 2.76 Å) owing to the employment of the 6-tungstotellurate(VI) salt (Na6[TeW6O24]·22H2O) as a cocrystallization agent. Two of these disc-shaped Anderson-type polyoxoanions [TeW6O24]6- separate two asymmetric units comprising one crystallographic heterodimer of abPPO4, thus resulting in very interesting crystal packing.

Subject Areas: Biology and Bio-materials, Chemistry

Instruments: I04-1-Macromolecular Crystallography (fixed wavelength)

Added On: 25/02/2015 10:37


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