Expression and purification of the recombinant orfD
product. (A) SDS/PAGE of the enzyme. Lanes: 1, low
molecular mass markers; 2, the pellet of the extract from E.
coli M15 (pREP4, pQCLD41) culture after induction with
isopropyl β-d-thiogalactopyranoside (IPTG); 3, the
supernatant of the same extract; 4, proteins passed through an
Ni-nitrilotriacetic acid agarose column; 5, the fraction eluted with 50
mM imidazole; 6, purified enzyme (1 μg) eluted with 200 mM imidazole.
(B) Native PAGE of the purified enzyme. Lanes: 1, high
molecular mass markers; 2, purified enzyme (0.7 μg).