The actomyosin molecular motor, the motor composed of myosin II and actin filament, is responsible for muscle contraction, converting chemical energy into mechanical work. Although recent single molecule and structural studies have shed new light on the energy-converting mechanism, the physical basis of the molecular-level mechanism remains unclear because of the experimental limitations. To provide a clue to resolve the controversy between the lever-arm mechanism and the Brownian ratchet-like mechanism, we here report an in silico single molecule experiment of an actomyosin motor. When we placed myosin on an actin filament and allowed myosin to move along the filament, we found that myosin exhibits a unidirectional Brownian motion along the filament. This unidirectionality was found to arise from the combination of a nonequilibrium condition realized by coupling to the ATP hydrolysis and a ratchet-like energy landscape inherent in the actin-myosin interaction along the filament, indicating that a Brownian ratchet-like mechanism contributes substantially to the energy conversion of this molecular motor.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867847 | PMC |
| http://dx.doi.org/10.1073/pnas.0911830107 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
PhAsO as a Strong Hydrogen-Bond Acceptor in Cocrystals with Hydrogen Peroxide and Dihydroperoxides.
Inorg Chem
January 2025
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia.
Hydrogen-bonded cocrystals have attracted considerable attention as they allow fine-tuning of properties through the choice of hydrogen-bond donors and acceptors. In this study, triphenylarsine oxide (PhAsO) is introduced as a strong hydrogen-bond acceptor molecule. Due to its higher Lewis basicity compared to triphenylphosphine oxide (PhPO), it acts as a strong hydrogen-bond acceptor, which is demonstrated in six new cocrystals with HO and -di(hydroperoxy)cycloalkanes.
View Article and Find Full Text PDFA novel cellulose-derived graphite carbon/ZnO composite by atomic layer deposition as an over-wideband microwave absorbent.
Phys Chem Chem Phys
January 2025
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China.
It is a major challenge to obtain broadband microwave absorption (MA) properties using low dielectric or magnetic nanoparticle-decorated carbon composites due to the limited single conductive loss or polarization loss of the carbon materials used as substrates. Novel pure cellulose-derived graphite carbon (CGC) materials can be used as an exceptional substrate option due to their special defective graphitic carbon structure, which provides both conduction and polarization loss. Herein, CGC@ZnO composites were first synthesized by atomic layer deposition (ALD) for use as microwave absorbents.
View Article and Find Full Text PDFA novel ADP-directed chaperone function facilitates the ATP-driven motor activity of SARS-CoV helicase.
Nucleic Acids Res
January 2025
Single-Molecule and Cell Mechanobiology Laboratory, Daejeon, 34141, South Korea.
Helicase is a nucleic acid motor that catalyses the unwinding of double-stranded (ds) RNA and DNA via ATP hydrolysis. Helicases can act either as a nucleic acid motor that unwinds its ds substrates or as a chaperone that alters the stability of its substrates, but the two activities have not yet been reported to act simultaneously. Here, we used single-molecule techniques to unravel the synergistic coordination of helicase and chaperone activities, and found that the severe acute respiratory syndrome coronavirus helicase (nsp13) is capable of two modes of action: (i) binding of nsp13 in tandem with the fork junction of the substrate mechanically unwinds the substrate by an ATP-driven synchronous power stroke; and (ii) free nsp13, which is not bound to the substrate but complexed with ADP in solution, destabilizes the substrate through collisions between transient binding and unbinding events with unprecedented melting capability.
View Article and Find Full Text PDFIdentical Fe-N Sites with Different Reactivity: Elucidating the Effect of Support Curvature.
ACS Appl Mater Interfaces
January 2025
CEITEC-Central European Institute of Technology, Brno University of Technology, Purkyňova 123, Brno 61200, Czech Republic.
Detailed atomic-scale understanding is a crucial prerequisite for rational design of next-generation single-atom catalysts (SACs). However, the sub-ångström precision needed for systematic studies is challenging to achieve on common SACs. Here, we present a two-dimensional (2D) metal-organic system featuring Fe-N single-atom sites, where the metal-organic structure is modulated by 0.
View Article and Find Full Text PDFSingle-Cell Proteomics Uncovers Dual Traits of Dermal Sheath Cells in Wound Repair.
Adv Wound Care (New Rochelle)
January 2025
Translational Medicine Center, Baotou Central Hospital (Baotou Clinical Medical College, Affiliated to Inner Mongolia Medical University), Baotou, China.
Wound healing is a dynamic process involving multiple cell types and signaling pathways. Dermal sheath cells (DSCs), residing surrounding hair follicles, play a critical role in tissue repair, yet their regulatory mechanisms remain unclear. This study used single-cell proteomics with the mouse model to explore DSC function across different healing stages.
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!