Incorporation of Copper Ions into T2/T3 Centers of Two-Domain Laccases
- 26 Downloads
Laccase belongs to the family of copper-containing oxidases. A study was made of the mechanism that sustains the incorporation of copper ions into the T2/T3 centers of recombinant two-domain laccase Streptomyces griseoflavus Ac-993. The occupancy of the T3 center by copper ions was found to increase with an increasing copper content in the culture medium and after dialysis of the protein preparation against a copper sulfate-containing buffer. The T2 center was filled only when overproducer strain cells were grown at a higher copper concentration in the medium. Two-domain laccases were assumed to possess a channel that serves to deliver copper ions to the T3 center during the formation of the three-dimensional laccase conformation and dialysis of the protein preparation. A narrower channel leads to the T2 center in two-domain laccases compared with three-domain ones, rendering the center less accessible for copper atoms. The incorporation of copper ions into the T2 center of two-domain laccases is likely to occur in the course of their biosynthesis or the formation of a functional trimer.
Keywordstwo-domain laccases T2/T3 copper centers channels X-ray structures Streptomyces griseoflavus
S. griseoflavus small laccase
Unable to display preview. Download preview PDF.
- 8.Glazunova O.A., Polyakov K.M., Fedorova T.V., et al. 2015. Elucidation of the crystal structure of Coriolopsis caperata laccase: Restoration of the structure and activity of the native enzyme from the T2-depleted form by copper ions. Acta Crystallogr. Sect. D: Biol. Crystallogr. 71, 854–861.CrossRefGoogle Scholar
- 10.Kostareva O.S., Gabdulkhakov A.G., Melnik B.S., et al. 2016. An increased copper ion content in Streptomyces griseoflavus laccase improves the thermostability of the protein. Aktual′n. Vopr. Biol. Fiz. Khim. 1, 236–239.Google Scholar