TY - JOUR
T1 - The difference a Se makes?
T2 - Oxygen-tolerant hydrogen production by the [NiFeSe]-hydrogenase from Desulfomicrobium baculatum
AU - Parkin, Alison
AU - Goldet, Gabrielle
AU - Cavazza, Christine
AU - Fontecilla-Camps, Juan C
AU - Armstrong, Fraser A
PY - 2008/10/8
Y1 - 2008/10/8
N2 - Protein film voltammetry studies of the [NiFeSe]-hydrogenase from Desulfomicrobium baculatum show it to be a highly efficient H2 cycling catalyst. In the presence of 100% H2, the ratio of H2 production to H2 oxidation activity is higher than for any conventional [NiFe]-hydrogenases (lacking a selenocysteine ligand) that have been investigated to date. Although traces of O2 (<1%) rapidly and completely remove H2 oxidation activity, the enzyme sustains partial activity for H2 production even in the presence of 1% O2 in the atmosphere. That H2 production should be partly allowed, whereas H2 oxidation is not, is explained because the inactive product of O2 attack is reductively reactivated very rapidly, but this requires a potential that is almost as negative as the thermodynamic potential for the 2H(+)/H2 couple. The study provides further encouragement and clues regarding the feasibility of microbial/enzymatic H2 production free from restrictions of anaerobicity.
AB - Protein film voltammetry studies of the [NiFeSe]-hydrogenase from Desulfomicrobium baculatum show it to be a highly efficient H2 cycling catalyst. In the presence of 100% H2, the ratio of H2 production to H2 oxidation activity is higher than for any conventional [NiFe]-hydrogenases (lacking a selenocysteine ligand) that have been investigated to date. Although traces of O2 (<1%) rapidly and completely remove H2 oxidation activity, the enzyme sustains partial activity for H2 production even in the presence of 1% O2 in the atmosphere. That H2 production should be partly allowed, whereas H2 oxidation is not, is explained because the inactive product of O2 attack is reductively reactivated very rapidly, but this requires a potential that is almost as negative as the thermodynamic potential for the 2H(+)/H2 couple. The study provides further encouragement and clues regarding the feasibility of microbial/enzymatic H2 production free from restrictions of anaerobicity.
UR - http://www.scopus.com/inward/record.url?scp=53549119985&partnerID=8YFLogxK
U2 - 10.1021/ja803657d
DO - 10.1021/ja803657d
M3 - Article
C2 - 18781742
SN - 0002-7863
VL - 130
SP - 13410
EP - 13416
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 40
ER -