Using polarization fluorimetry, the orientation and mobility of 1,5-IAEDANS specifically bound to Cys707 of myosin subfragment-1 (S1) were studied in ghost muscle tropomyosin-containing fibers in the absence and in the presence of MgADP, MgAMP-PNP, MgATPgammaS, or MgATP. Modeling of various intermediate states was accompanied by discrete changes in actomyosin orientation and mobility of fluorescent dye dipoles. This suggests multistep changes in the structural state of the myosin head during the ATPase cycle. Maximal differences in the probe orientation by 4 degrees and its mobility by 30% were found between actomyosin states in the presence of MgADP and MgATP. It is suggested that interaction of S1 with F-actin induces nucleotide-dependent rotation of the whole motor domain of the myosin head or only the dye-binding site and also change in the head mobility.
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http://dx.doi.org/10.1007/s10541-005-0237-6 | DOI Listing |
Carbohydr Polym
March 2025
School of Materials Science and Engineering, Nanjing University of Science & Technology, Nanjing 210094, PR China. Electronic address:
The high-dynamic, high-loading environment in the joint cavity puts urgent demands on the cartilage regenerative materials with shear responsiveness and lubrication. Here, a new type of injectable hydrogel composed of oxidized hyaluronic acid (OHA), adipic dihydrazide-grafted hyaluronic acid (HA-ADH), oxidized chondroitin sulfate (OChs), and decellularized extracellular matrix methacrylate (dECMMA) was fabricated. The aldehyde groups in OHA and OChs reacted with the amino groups in HA-ADH to form a dynamic hydrogel, which was then covalently crosslinked with dECMMA to create a dual-crosslinked hydrogel with sufficient mechanical strength.
View Article and Find Full Text PDFPLoS One
January 2025
Faculty of Science, School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD, Australia.
Not all corals are attached to the substrate; some taxa are solitary and free-living, allowing them to migrate into preferred habitats. However, the lifestyle of these mobile corals, including how they move and navigate for migration, remains largely obscure. This study investigates the specific biomechanics of Cycloseris cyclolites, a free-living coral species, during phototactic behaviour in response to blue and white light stimuli.
View Article and Find Full Text PDFBMC Neurol
January 2025
Graduate School of Physical Education, Myongji University, Mingzhi Road, Churen District, Yongin, 17058, Gyeonggi Province, Republic of Korea.
Background: This study evaluates the comprehensive impact of different exercise interventions on the quality of life in stroke patients through network meta-analysis, aiming to provide scientific evidence for developing more effective rehabilitation programs and improving patients' physical, psychological, and social functions.
Methods: This systematic review, registered in PROSPERO (CRD42024541517) and following PRISMA guidelines, searched multiple databases (PubMed, Web of Science, EMbase, Cochrane, Ebsco) until November 1, 2024. Studies were selected based on the PICOS criteria, including RCTs on stroke and exercise.
Sci Rep
January 2025
Research and Development, Aesculap AG, Tuttlingen, Germany.
In clinical movement biomechanics, kinematic measurements are collected to characterise the motion of articulating joints and investigate how different factors influence movement patterns. Representative time-series signals are calculated to encapsulate (complex and multidimensional) kinematic datasets succinctly. Exacerbated by numerous difficulties to consistently define joint coordinate frames, the influence of local frame orientation and position on the characteristics of the resultant kinematic signals has been previously proven to be a major limitation.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529, USA.
Understanding the nature of π-stacking interactions is important to molecular recognition, self-assembly, and organic semiconductors. The stack bond order (SBO) model of π-stacking has shown that the conformations of dimers are found at orientations where the combinations of monomer MOs are overall bonding within the stack. DFT calculations show that parallel displaced minima found on the potential energy surface for the π-stacked dimers of pentacene and perfluoropentacene occur when the dimer MOs are constructed from combinations of monomer MOs with an allowed SBO.
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