F-protein, a consistent contaminant of myosin preparations, has been shown to be phosphofructokinase, the key regulatory enzyme of glycolysis. In homogenates of rigor muscle most of the phosphofructokinase sediments with the myofibrils, suggesting that in the living muscle cell phosphofructokinase is not in the soluble fraction as was formerly thought, but bound to the myofibrils. Fluorescent antibody to F-protein labels myofibrils in a zone in each half of the A-band. The increase in separation of the zones across the A-band with increase in sarcomere length suggests that the antibody binds to the parts of the cross-bridge regions of the thick filament within the H-zone. It therefore seems likely that phosphofructokinase is located in the cross-bridge region of the thick filament, but that access of antibody is restricted by overlapping thin filaments.
Download full-text PDF |
Source |
---|
Circ Res
January 2025
Department of Integrative Pathophysiology, Medical Faculty Mannheim, DZHK Partnersite Mannheim-Heidelberg, University of Heidelberg, Germany (S.L.).
This review examines the giant elastic protein titin and its critical roles in heart function, both in health and disease, as discovered since its identification nearly 50 years ago. Encoded by the TTN (titin gene), titin has emerged as a major disease locus for cardiac disorders. Functionally, titin acts as a third myofilament type, connecting sarcomeric Z-disks and M-bands, and regulating myocardial passive stiffness and stretch sensing.
View Article and Find Full Text PDFDiscov Nano
December 2024
School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, 611731, Sichuan, People's Republic of China.
LiTiO (LTO) batteries are known for safety and long lifespan due to zero-strain and stable lattice. However, their low specific capacity and lithium-ion diffusion limit practical use. This study explored modifying LTO through yttrium doping by hydrothermal method to form LiYTiO nanoparticles.
View Article and Find Full Text PDFBMJ Case Rep
December 2024
General Surgery, MS Ramaiah University of Applied Sciences, Bangalore, Karnataka, India.
Mondor disease (MD) is a benign inflammatory disorder of the veins over the thoracoabdominal wall. Although the disease has been described for a century, very few descriptions in literature are available. This is due to a lack of awareness among treating physicians about the disease entity as well as the self-limiting course of the disease.
View Article and Find Full Text PDFPLoS One
December 2024
Conservation Science Wildlife Health, San Diego Zoo Wildlife Alliance, Escondido, California, United States of America.
Andean bears (Tremarctos ornatus) forage extensively on bromeliads (Puya spp.) across their range, although their selectivity for bromeliads is less understood. We report on foraging activity by Andean bears on two species of bromeliad, Puya leptostachya and Puya membranacea, in high elevation puna grasslands (3499-3806 m.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
School of Civil Engineering, Southwest Forestry University, Kunming 650224, China.
The tensile properties of fiber metal laminates were examined at temperatures ranging from 30 °C to 180 °C in this paper through the integration of numerical simulation techniques, experimental measurements, and digital image correlation techniques. The laminates were initially modeled using finite elements, and the failure behavior of porous basalt-fiber-reinforced aluminum alloy plates was numerically simulated. Consequently, metal fiber laminate stress-strain responses were varied by numerous tensile experiments conducted at varying temperatures.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!