Structural biology: LEXSY proteins for NMR and X-ray crystallography

The applicability of LEXSY for structural biology was demonstrated by successful ¹⁵N-HSQC NMR analysis of a 28 kDa ¹⁵N-Val labeled protein purified from recombinant LEXSY strain grown in a synthetic LEXSY cultivation medium. All 18 Val residues of in vivo labeled protein could be completely assigned in ¹⁵N-HSQC NMR spectrum in full agreement with X-ray crystallography (Niculae et al. 2006). Since Leishmania tarentolae is auxotrophic for 11 amino acids and can be grown in chemically defined media multiple options for labeling strategies are offered. Alternatively to chemically defined media labeling strategies in complex media were developed (Foldynová-Trantírková et al. 2009).

¹⁵N-HSQC NMR analysis of ¹⁵N-Val labeled EGFP purified from recombinant LEXSY strain. For detailed description refer to Niculae et al. (2006).

It was shown, that LEXSY-expressed proteins can be subjected successfully to crystallography and X-ray analysis. The resolution of a new protein structure was achieved for LEXSY expressed hu Cu/Zn superoxide dismutase SOD1 (Gazdak et al. 2010).

Structure determination of the new P2₁2₁2₁ crystal form of LEXSY-produced human Cu/Zn superoxide dismutase (SOD1). The asymmetric unit contains six SOD dimers arranged as two triangular wheels around sulfate ions. The wheels are arranged in a side-to-side fashion (Gazdag et al. 2010).