PubMed:35090895 JSON TXT

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Glycosmos6-MAT

{"project":"Glycosmos6-MAT","denotations":[{"id":"T1","span":{"begin":93,"end":107},"obj":"http://purl.obolibrary.org/obo/MAT_0000453"},{"id":"T2","span":{"begin":101,"end":107},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"T3","span":{"begin":109,"end":115},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"T4","span":{"begin":123,"end":128},"obj":"http://purl.obolibrary.org/obo/MAT_0000294"},{"id":"T5","span":{"begin":435,"end":441},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"T6","span":{"begin":462,"end":468},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"T7","span":{"begin":549,"end":555},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"T8","span":{"begin":699,"end":704},"obj":"http://purl.obolibrary.org/obo/MAT_0000294"},{"id":"T9","span":{"begin":1120,"end":1126},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"T10","span":{"begin":1140,"end":1146},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"T11","span":{"begin":1152,"end":1167},"obj":"http://purl.obolibrary.org/obo/MAT_0000453"},{"id":"T12","span":{"begin":1542,"end":1549},"obj":"http://purl.obolibrary.org/obo/MAT_0000025"}],"text":"Exploring the super-relaxed state of myosin in myofibrils from fast-twitch, slow-twitch, and cardiac muscle.\nMuscle myosin heads, in the absence of actin, have been shown to exist in two states, the relaxed (turnover ∼0.05 s-1) and super-relaxed states (SRX, 0.005 s-1) using a simple fluorescent ATP chase assay (Hooijman, P. et al (2011) Biophys. J.100, 1969-1976). Studies have normally used purified proteins, myosin filaments, or muscle fibers. Here we use muscle myofibrils, which retain most of the ancillary proteins and 3-D architecture of muscle and can be used with rapid mixing methods. Recording timescales from 0.1 to 1000 s provides a precise measure of the two populations of myosin heads present in relaxed myofibrils. We demonstrate that the population of SRX states is formed from rigor cross bridges within 0.2 s of relaxing with fluorescently labeled ATP, and the population of SRX states is relatively constant over the temperature range of 5 °C-30 °C. The SRX population is enhanced in the presence of mavacamten and reduced in the presence of deoxy-ATP. Compared with myofibrils from fast-twitch muscle, slow-twitch muscle, and cardiac muscles, myofibrils require a tenfold lower concentration of mavacamten to be effective, and mavacamten induced a larger increase in the population of the SRX state. Mavacamten is less effective, however, at stabilizing the SRX state at physiological temperatures than at 5 °C. These assays require small quantities of myofibrils, making them suitable for studies of model organism muscles, human biopsies, or human-derived iPSCs."}

NCBITAXON

{"project":"NCBITAXON","denotations":[{"id":"T1","span":{"begin":1551,"end":1556},"obj":"OrganismTaxon"},{"id":"T2","span":{"begin":1570,"end":1575},"obj":"OrganismTaxon"}],"attributes":[{"id":"A1","pred":"db_id","subj":"T1","obj":"9606"},{"id":"A2","pred":"db_id","subj":"T2","obj":"9606"}],"text":"Exploring the super-relaxed state of myosin in myofibrils from fast-twitch, slow-twitch, and cardiac muscle.\nMuscle myosin heads, in the absence of actin, have been shown to exist in two states, the relaxed (turnover ∼0.05 s-1) and super-relaxed states (SRX, 0.005 s-1) using a simple fluorescent ATP chase assay (Hooijman, P. et al (2011) Biophys. J.100, 1969-1976). Studies have normally used purified proteins, myosin filaments, or muscle fibers. Here we use muscle myofibrils, which retain most of the ancillary proteins and 3-D architecture of muscle and can be used with rapid mixing methods. Recording timescales from 0.1 to 1000 s provides a precise measure of the two populations of myosin heads present in relaxed myofibrils. We demonstrate that the population of SRX states is formed from rigor cross bridges within 0.2 s of relaxing with fluorescently labeled ATP, and the population of SRX states is relatively constant over the temperature range of 5 °C-30 °C. The SRX population is enhanced in the presence of mavacamten and reduced in the presence of deoxy-ATP. Compared with myofibrils from fast-twitch muscle, slow-twitch muscle, and cardiac muscles, myofibrils require a tenfold lower concentration of mavacamten to be effective, and mavacamten induced a larger increase in the population of the SRX state. Mavacamten is less effective, however, at stabilizing the SRX state at physiological temperatures than at 5 °C. These assays require small quantities of myofibrils, making them suitable for studies of model organism muscles, human biopsies, or human-derived iPSCs."}

Anatomy-MAT

{"project":"Anatomy-MAT","denotations":[{"id":"T1","span":{"begin":93,"end":107},"obj":"Body_part"},{"id":"T2","span":{"begin":109,"end":115},"obj":"Body_part"},{"id":"T3","span":{"begin":123,"end":128},"obj":"Body_part"},{"id":"T4","span":{"begin":435,"end":441},"obj":"Body_part"},{"id":"T5","span":{"begin":462,"end":468},"obj":"Body_part"},{"id":"T6","span":{"begin":549,"end":555},"obj":"Body_part"},{"id":"T7","span":{"begin":699,"end":704},"obj":"Body_part"},{"id":"T8","span":{"begin":1120,"end":1126},"obj":"Body_part"},{"id":"T9","span":{"begin":1140,"end":1146},"obj":"Body_part"},{"id":"T10","span":{"begin":1152,"end":1167},"obj":"Body_part"},{"id":"T11","span":{"begin":1542,"end":1549},"obj":"Body_part"}],"attributes":[{"id":"A1","pred":"mat_id","subj":"T1","obj":"http://purl.obolibrary.org/obo/MAT_0000453"},{"id":"A2","pred":"mat_id","subj":"T2","obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"A3","pred":"mat_id","subj":"T3","obj":"http://purl.obolibrary.org/obo/MAT_0000294"},{"id":"A4","pred":"mat_id","subj":"T4","obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"A5","pred":"mat_id","subj":"T5","obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"A6","pred":"mat_id","subj":"T6","obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"A7","pred":"mat_id","subj":"T7","obj":"http://purl.obolibrary.org/obo/MAT_0000294"},{"id":"A8","pred":"mat_id","subj":"T8","obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"A9","pred":"mat_id","subj":"T9","obj":"http://purl.obolibrary.org/obo/MAT_0000025"},{"id":"A10","pred":"mat_id","subj":"T10","obj":"http://purl.obolibrary.org/obo/MAT_0000453"},{"id":"A11","pred":"mat_id","subj":"T11","obj":"http://purl.obolibrary.org/obo/MAT_0000025"}],"text":"Exploring the super-relaxed state of myosin in myofibrils from fast-twitch, slow-twitch, and cardiac muscle.\nMuscle myosin heads, in the absence of actin, have been shown to exist in two states, the relaxed (turnover ∼0.05 s-1) and super-relaxed states (SRX, 0.005 s-1) using a simple fluorescent ATP chase assay (Hooijman, P. et al (2011) Biophys. J.100, 1969-1976). Studies have normally used purified proteins, myosin filaments, or muscle fibers. Here we use muscle myofibrils, which retain most of the ancillary proteins and 3-D architecture of muscle and can be used with rapid mixing methods. Recording timescales from 0.1 to 1000 s provides a precise measure of the two populations of myosin heads present in relaxed myofibrils. We demonstrate that the population of SRX states is formed from rigor cross bridges within 0.2 s of relaxing with fluorescently labeled ATP, and the population of SRX states is relatively constant over the temperature range of 5 °C-30 °C. The SRX population is enhanced in the presence of mavacamten and reduced in the presence of deoxy-ATP. Compared with myofibrils from fast-twitch muscle, slow-twitch muscle, and cardiac muscles, myofibrils require a tenfold lower concentration of mavacamten to be effective, and mavacamten induced a larger increase in the population of the SRX state. Mavacamten is less effective, however, at stabilizing the SRX state at physiological temperatures than at 5 °C. These assays require small quantities of myofibrils, making them suitable for studies of model organism muscles, human biopsies, or human-derived iPSCs."}

Anatomy-UBERON

CL-cell

{"project":"CL-cell","denotations":[{"id":"T1","span":{"begin":435,"end":448},"obj":"Cell"}],"attributes":[{"id":"A1","pred":"cl_id","subj":"T1","obj":"http://purl.obolibrary.org/obo/CL:0000187"}],"text":"Exploring the super-relaxed state of myosin in myofibrils from fast-twitch, slow-twitch, and cardiac muscle.\nMuscle myosin heads, in the absence of actin, have been shown to exist in two states, the relaxed (turnover ∼0.05 s-1) and super-relaxed states (SRX, 0.005 s-1) using a simple fluorescent ATP chase assay (Hooijman, P. et al (2011) Biophys. J.100, 1969-1976). Studies have normally used purified proteins, myosin filaments, or muscle fibers. Here we use muscle myofibrils, which retain most of the ancillary proteins and 3-D architecture of muscle and can be used with rapid mixing methods. Recording timescales from 0.1 to 1000 s provides a precise measure of the two populations of myosin heads present in relaxed myofibrils. We demonstrate that the population of SRX states is formed from rigor cross bridges within 0.2 s of relaxing with fluorescently labeled ATP, and the population of SRX states is relatively constant over the temperature range of 5 °C-30 °C. The SRX population is enhanced in the presence of mavacamten and reduced in the presence of deoxy-ATP. Compared with myofibrils from fast-twitch muscle, slow-twitch muscle, and cardiac muscles, myofibrils require a tenfold lower concentration of mavacamten to be effective, and mavacamten induced a larger increase in the population of the SRX state. Mavacamten is less effective, however, at stabilizing the SRX state at physiological temperatures than at 5 °C. These assays require small quantities of myofibrils, making them suitable for studies of model organism muscles, human biopsies, or human-derived iPSCs."}