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"Catch," a state where some invertebrate muscles sustain high tension over long periods of time with little energy expenditure (low ATP hydrolysis rate) is similar to the "latch" state of vertebrate smooth muscles. Its induction and release involve Ca(2+)-dependent phosphatase and cAMP-dependent protein kinase, respectively. Molecular mechanisms for catch(More)
Using a recently introduced electrophoresis system [Kashino et al. (2001) Electrophoresis 22: 1004], components of low-molecular-mass polypeptides were analyzed in detail in photosystem II (PSII) complexes isolated from a thermophilic cyanobacterium, Thermosynechococcus vulcanus (formerly, Synechococcus vulcanus). PsbE, the large subunit polypeptide of(More)
Molluscan catch muscles contain polypeptides of 110-120 kDa in size which have the same partial amino acid sequences as those of the myosin heavy chain (MHC). Here we provide evidence that these polypeptides are major components only of the catch-type muscles (their estimated molar ratio to MHC is approximately 1:1) and they are alternative products of the(More)
"Catch" is the state where some invertebrate muscles sustain high tension for long periods at low ATP hydrolysis rates. Physiological studies using muscle fibers have not yet fully provided the details of the initiation process of the catch state. The process was extensively studied by using an in vitro reconstitution assay with several phosphatase(More)
Outer and inner envelope membranes of spinach chloroplasts were isolated using floatation centrifugation followed by sedimentation sucrose density gradient centrifugation after disruption of intact chloroplasts by freezing and thawing. Two major fractions with buoyant densities of 1.11 and 1.08 g cm-3 and a minor fraction with a density of 1.15 g cm-3 were(More)
Catch muscles are found in some invertebrates which can maintain high passive tension with little energy expenditure for long periods after their active contraction. Twitchin in the catch muscles has the ability to facilitate the tight binding of thick filaments to thin filaments, which is the structural basis of the catch tension. We defined this ability(More)
Twitchin, also called mini-titin, is structurally related to the giant elastic protein connectin/titin, and has been found in not only striated but also smooth muscles of bivalves. Many bivalve smooth muscles such as byssus retractor muscles and the opaque part of adductor muscles are known as catch muscles that can maintain high passive tension with little(More)
In actomyosin in vitro motility assays, orientation of myosin molecules affects their interaction with actin. We obtained long tracks of myosin molecules with uniform orientation. Bipolar filaments about 50 microm long were made from myosin rod prepared from molluscan smooth muscles, to which rabbit skeletal-muscle myosin bound, creating long synthetic(More)
Biomolecular motors such as myosin, kinesin and dynein are protein machines that can drive directional movement along cytoskeletal tracks and have the potential to be used as molecule-sized actuators. Although control of the velocity and directionality of biomolecular motors has been achieved, the design and construction of novel biomolecular motors remains(More)
Molluscan muscle twitchin, a titin/connectin-related giant protein, regulates interactions between actin and myosin filaments at low Ca2+ concentrations. When it is dephosphorylated, actin filaments tightly bind to myosin filaments, resulting in the catch state known as the state of high passive tension with very low energy consumption. Yet when twitchin is(More)