Broad antibiotic resistance profile of the subclass B3 metallo-β-lactamase GOB-1, a di-zinc enzyme.

The metallo-β-lactamase (MBL) GOB-1 was expressed via a T7 expression system in Escherichia coli BL21(DE3). The MBL was purified to homogeneity and shown to exhibit a broad substrate profile, hydrolyzing all the tested β-lactam compounds efficiently. The GOB enzymes are unique among MBLs due to the presence of a glutamine residue at position 116, a zinc-binding residue in all known class B1 and B3 MBL structures.

Structural basis for binding of cyclic 2-oxoglutarate analogues to factor-inhibiting hypoxia-inducible factor.

Aromatic analogues of the 2-oxoglutarate co-substrate of the hypoxia-inducible factor hydroxylases are shown to bind at the active site iron: Pyridine-2,4-dicarboxylate binds as anticipated with a single molecule chelating the iron in a bidentate manner. The binding mode of a hydroxamic acid analogue, at least in the crystalline state, is unusual because two molecules of the inhibitor are observed at the active site and partial displacement of the iron binding aspartyl residue was observed.

Application of a proteolysis/mass spectrometry method for investigating the effects of inhibitors on hydroxylase structure.

Limited proteolysis coupled to matrix-assisted laser desorption/ionization (MALDI) mass spectrometric analyses can be used to screen for compounds that alter protein structure by monitoring stabilizing/destabilizing effects with respect to the rate and nature of proteolysis. When applied to prolyl hydroxylase 2, a key enzyme involved in human oxygen sensing, the method efficiently revealed differential effects on proteolytic stability for structurally similar compounds and for different substrates.

Evaluation of aspirin metabolites as inhibitors of hypoxia-inducible factor hydroxylases.

Known and potential aspirin metabolites were evaluated as inhibitors of oxygen-sensing hypoxia-inducible transcription factor (HIF) hydroxylases; some of the metabolites were found to stabilise HIF-alpha in cells.