Multihaem cytochromes are essential to the energetics of organisms capable of bioremediation and energy production. The haems in several of these cytochromes have been discriminated thermodynamically and their individual rates of reduction by small electron donors were characterized. The kinetic characterization of individual haems used the Marcus theory of electron transfer and assumed that the rates of reduction of each haem by sodium dithionite depend only on the driving force, while electrostatic interactions were neglected. To determine the relative importance of these factors in controlling the rates, we studied the effect of ionic strength on the redox potential and the rate of reduction by dithionite of native Methylophilus methylotrophus cytochrome c″ and three mutants at different pH values. We found that the main factor determining the rate is the driving force and that Marcus theory describes this satisfactorily. This validates the method of the simultaneous fitting of kinetic and thermodynamic data in multihaem cytochromes and opens the way for further investigation into the mechanisms of these proteins.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.bbabio.2013.02.006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Large exciton binding energy in a bulk van der Waals magnet from quasi-1D electronic localization.
Nat Commun
January 2025
Department of Physics, University of Michigan, Ann Arbor, MI, USA.
Excitons, bound electron-hole pairs, influence the optical properties in strongly interacting solid-state systems and are typically most stable and pronounced in monolayer materials. Bulk systems with large exciton binding energies, on the other hand, are rare and the mechanisms driving their stability are still relatively unexplored. Here, we report an exceptionally large exciton binding energy in single crystals of the bulk van der Waals antiferromagnet CrSBr.
View Article and Find Full Text PDFDiffusion-driven transient hydrogenation in metal superhydrides at extreme conditions.
Nat Commun
January 2025
Shanghai Key Laboratory MFree, Institute for Shanghai Advanced Research in Physical Sciences, Shanghai, 201203, China.
In recent years, metal hydride research has become one of the driving forces of the high-pressure community, as it is believed to hold the key to superconductivity close to ambient temperature. While numerous novel metal hydride compounds have been reported and extensively investigated for their superconducting properties, little attention has been focused on the atomic and electronic states of hydrogen, the main ingredient in these novel compounds. Here, we present combined H- and La-NMR data on lanthanum superhydrides, LaH, (x = 10.
View Article and Find Full Text PDFSwarm systems as a platform for open-ended evolutionary dynamics.
Philos Trans A Math Phys Eng Sci
January 2025
Binghamton Center of Complex Systems, Binghamton University, State University of New York, Binghamton, NY 13902, USA.
Artificial swarm systems have been extensively studied and used in computer science, robotics, engineering and other technological fields, primarily as a platform for implementing robust distributed systems to achieve pre-defined objectives. However, such swarm systems, especially heterogeneous ones, can also be utilized as an ideal platform for creating open-ended evolutionary dynamics that do not converge toward pre-defined goals but keep exploring diverse possibilities and generating novel outputs indefinitely. In this article, we review Swarm Chemistry and its variants as concrete sample cases to illustrate beneficial characteristics of heterogeneous swarm systems, including the cardinality leap of design spaces, multi-scale structures/behaviours and their diversity, and robust self-organization, self-repair and ecological interactions of emergent patterns, all of which serve as the driving forces for open-ended evolutionary processes.
View Article and Find Full Text PDFExtracellular volume expansion drives vertebrate axis elongation.
Curr Biol
January 2025
Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA. Electronic address:
The vertebrate bauplan is primarily established via the formation of embryonic tissues in a head-to-tail progression. The mechanics of this elongation, which requires the presomitic mesoderm (PSM), remain poorly understood. Here, we find that avian PSM explants can elongate autonomously when physically confined in vitro, producing a pushing force promoting posterior elongation of the embryo.
View Article and Find Full Text PDFCentury-long West Antarctic snow accumulation changes induced by tropical teleconnections.
Sci Adv
January 2025
Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
Ice core measurements reveal dipole-like snow accumulation trends over West Antarctica throughout the 20th century, with an increase of >2000 billion metric tons over the Antarctic Peninsula and Ellsworth Land but a decrease of ~500 billion metric tons over Marie Byrd Land. Although atmospheric teleconnections were frequently revealed, linking variability between tropics and higher latitudes on interannual and decadal timescales, centennial-scale teleconnection is absent from literature. Here, using statistical analysis and numerical experiments, we reveal that changes of tropical oceans throughout the 20th century drive the long-term Antarctic snowfall trend.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!