The inner membrane system of mitochondria us known to consist of two contiguous but distinct membranes: the inner boundary membrane, which apposes the outer membrane, and the cristal membrane, which forms tubules or lamellae in the interior. Using immunolabeling and transmission electron microscopy of bovine heart tissue, we have calculated that around 94% of both Complex III of the respiratory chain and the ATP synthase are located in the cristal membrane, and only around 6% of either is in the inner boundary membrane. When accounting for the topographical ratio of cristal membrane versus inner boundary membrane, we find that both complexes exist at a 2.2-2.6-fold higher concentration in the cristal membrane. The residual protein in the inner boundary membrane may be newly assembled complexes destined for cristal membranes. Our results argue for restricted diffusion of complexes through the cristal junctions and indicate that the mitochondrial cristae comprise a regulated submitochondrial compartment specialized for ATP production.
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http://dx.doi.org/10.1016/s0014-5793(03)00633-1 | DOI Listing |
Int J Med Robot
October 2024
The Engineering Research Center of Intelligent Unmanned System, Ministry of Education, Shandong University, Jinan, China.
Background: Endoscopic submucosal dissection (ESD) is an effective treatment for early-stage gastrointestinal cancers. However, traditional surgical instruments lack accuracy and force-sensing.
Methods: A new type of continuum robot for ESD is designed.
Mitochondrion
September 2024
School of Integrative Biological & Chemical Sciences, The University of Texas Rio Grande Valley, United States; Medical Laboratory Sciences/Health & Biomedical Sciences, The University of Texas Rio Grande Valley, United States. Electronic address:
Mitochondrial optic atrophy-1 (OPA1) plays key roles in adapting mitochondrial structure to bioenergetic function. When transmembrane potential across the inner membrane (Δψ) is intact, long (L-OPA1) isoforms shape the inner membrane through membrane fusion and the formation of cristal junctions. When Δψ is lost, however, OPA1 is cleaved to short, inactive S-OPA1 isoforms by the OMA1 metalloprotease, disrupting mitochondrial structure and priming cellular stress responses such as apoptosis.
View Article and Find Full Text PDFArch Cardiovasc Dis
February 2023
Department of Cardiac and Thoracic Surgery, Cardiology Institute, Pitié-Salpêtrière Hospital, AP-HP, Sorbonne University Medical School, 75013 Paris, France; Paris Translational Research Centre for Organ Transplantation, Inserm, UMR-S970, 75015 Paris, France. Electronic address:
Membranes (Basel)
December 2022
TMA Process, 51100 Reims, France.
Hydrogen and carbon dioxide fermentation to methane, called bio-methanation, is a promising way to provide renewable and easy-to-store energy. The main challenge of bio-methanation is the low gas-to-liquid transfer of hydrogen. Gas injection through a porous membrane can be used to obtain microbubbles and high gas-to-liquid transfer.
View Article and Find Full Text PDFFood Chem
March 2023
Institute of Nutrition and Functional Foods (INAF), Dairy Science and Technology Research Centre (STELA), Department of Food Sciences, Université Laval, Quebec, Quebec G1V 0A6, Canada. Electronic address:
The milk fat globule membrane (MFGM), which surrounds and stabilizes the fat globules, is released in buttermilk during cream churning. MFGM has many health benefits due to its composition rich in phospholipids and membrane proteins. Many techniques have been tried to separate the MFGM from the remaining milk solids non-fat, but they are challenging to carry out at an industrial scale.
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