Enzymatic activity and catalytic hydrogen evolution in reduced and oxidized urease at mercury surfaces

0422414 - BFÚ 2014 RIV NL eng J - Journal Article
Černocká, Hana - Ostatná, Veronika - Paleček, Emil
Enzymatic activity and catalytic hydrogen evolution in reduced and oxidized urease at mercury surfaces.
Analytica Chimica Acta. Roč. 789, JUL30 (2013), s. 41-46. ISSN 0003-2670. E-ISSN 1873-4324
R&D Projects: GA ČR(CZ) GAP301/11/2055; GA ČR(CZ) GA13-00956S
Institutional research plan: CEZ:AV0Z50040702
Institutional support: RVO:68081707
Keywords : JACK BEAN UREASE * ELECTROCHEMICAL REDUCTION * AMALGAM ELECTRODES
Subject RIV: BO - Biophysics
Impact factor: 4.517, year: 2013

It was originally shown [10] that urease retains its enzymatic activity when adsorbed at bare mercury and solid amalgam surfaces. However the opinion later prevailed that, when adsorbed at bare metal electrodes, proteins are irreversibly denatured. Here we confirm that urease is enzymatically active at a bare solid amalgam surface as found by Santhanam et al., and we show that this enzyme is equally active at a thiol-modified amalgam surface. We also show that it is the reduced form of urease, which is enzymatically active at Hg surfaces. Oxidation of the protein, resulting in formation of disulfide bonds, strongly decreases the enzyme activity. Using constant current chronopotentiometric stripping (CPS) we show that the exposure of surface-attached urease to negative potentials results in the protein unfolding.
Permanent Link: http://hdl.handle.net/11104/0228550