Kylie A Vincent

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A new strategy is described for comparing, quantitatively, the ability of hydrogenases to tolerate exposure to O2 and anoxic oxidizing conditions. Using protein film voltammetry, the inherent sensitivities to these challenges (thermodynamic potentials and rates of reactions) have been measured for enzymes from a range of mesophilic microorganisms. In the(More)
The concept of a fuel cell dates back to 1839, from independent studies by Grove and Schoenbein. Like a battery, a fuel cell is a device for obtaining electrical energy directly from a chemical reaction, but unlike a battery, electrical power is sustained as long as the reacting chemicals are supplied to each electrode with the cathode receiving oxidant and(More)
Green algae such as Chlamydomonas reinhardtii synthesize an [FeFe] hydrogenase that is highly active in hydrogen evolution. However, the extreme sensitivity of [FeFe] hydrogenases to oxygen presents a major challenge for exploiting these organisms to achieve sustainable photosynthetic hydrogen production. In this study, the mechanism of oxygen inactivation(More)
Kaempferia galanga is a zingiberaceous medicinal plant distributed in the tropics and subtropics of Asia and Africa. In India it is cultivated throughout the plains for its aromatic rhizome. The methanol extract of the rhizome of K. galanga contains ethyl p-methoxy trans-cinnamate, which is highly cytotoxic to HeLa cells (Kosuge et al. 1985). Recently(More)
A molecular wire is used to connect two proteins through their physiologically relevant redox cofactors to facilitate direct electron transfer. Photosystem I (PS I) and an [FeFe]-hydrogenase (H(2)ase) serve as the test bed for this new technology. By tethering a photosensitizer with a hydrogen-evolving catalyst, attached by Fe-S coordination bonds between(More)
Use of hydrogen in fuel cells requires catalysts that are tolerant to oxygen and are able to function in the presence of poisons such as carbon monoxide. Hydrogen-cycling catalysts are widespread in the bacterial world in the form of hydrogenases, enzymes with unusual active sites composed of iron, or nickel and iron, that are buried within the protein. We(More)
We demonstrate an extreme test of O(2) tolerance for a biological hydrogen-cycling catalyst: the generation of electricity from just 3% H(2) released into still, ambient air using an open fuel cell comprising an anode modified with the unusual hydrogenase from Ralstonia metallidurans CH34, that oxidizes trace H(2) in atmospheric O(2), connected via a film(More)
Microbial interconversions between CO and CO2 are catalyzed by carbon monoxide dehydrogenases (CODH).1 These enzymes fall into three classes: Mo-CODH in which the active site is a CuMopterin, Ni-CODH in which the active site is a [Ni4Fe-5S] cluster, and Ni-CODH/ACS, in which a Ni-CODH is part of a larger complex coupling CO2 reduction to acetyl CoA(More)
Knallgas bacteria such as certain Ralstonia spp. are able to obtain metabolic energy by oxidizing trace levels of H2 using O2 as the terminal electron acceptor. The [NiFe] hydrogenases produced by these organisms are unusual in their ability to oxidize H2 in the presence of O2, which is a potent inactivator of most hydrogenases through attack at the active(More)