Effects of surface adsorption on catalytic activity of heavy meromyosin studied using a fluorescent ATP analogue.
AuthorsBalaz M, Sundberg M, Persson M, Kvassman J, Månsson A
JournalBiochemistry
PubMed ID17523677
'Biochemical studies in solution and with myosin motor fragments adsorbed to surfaces (in vitro motility assays) are invaluable for elucidation of actomyosin function. However, there is limited understanding of how surface adsorption affects motor properties, e.g., catalytic activity. Here we address this issue by comparing the catalytic activity of heavy ... More
Correlation between mechanical and enzymatic events in contracting skeletal muscle fiber.
AuthorsShepard A, Borejdo J
JournalBiochemistry
PubMed ID15005615
'The conventional hypothesis of muscle contraction postulates that the interaction between actin and myosin involves tight coupling between the power stroke and hydrolysis of ATP. However, some in vitro experiments suggested that hydrolysis of a single molecule of ATP caused multiple mechanical cycles. To test whether the tight coupling is ... More
Fluorescence measurements of nucleotide association with the Na(+)/K(+)-ATPase.
AuthorsPratap PR, Mikhaylyants LO, Olden-Stahl N,
JournalBiochim Biophys Acta
PubMed ID19595797
'The Na(+)/K(+)-ATPase, a membrane-associated ion pump, uses energy from the hydrolysis of ATP to pump 3 Na(+) ions out of and 2 K(+) into cells. The dependence of ATP hydrolysis on ATP concentration was measured using a fluorescence coupled-enzyme assay. The dependence on concentration of nucleotide association with the ATPase ... More
Simultaneous measurement of rotations of myosin, actin and ADP in a contracting skeletal muscle fiber.
AuthorsShepard AA, Dumka D, Akopova I, Talent J, Borejdo J
JournalJ Muscle Res Cell Motil
PubMed ID15711885
'The rotation of myosin heads and actin were measured simultaneously with an indicator of the enzymatic activity of myosin. To minimize complications due to averaging of signals from many molecules, the signal was measured in a small population residing in a femtoliter volume of a muscle fiber. The onset of ... More
Anisotropic diffusion of fluorescently labeled ATP in rat cardiomyocytes determined by raster image correlation spectroscopy.
AuthorsVendelin M, Birkedal R,
JournalAm J Physiol Cell Physiol
PubMed ID18815224
A series of experimental data points to the existence of profound diffusion restrictions of ADP/ATP in rat cardiomyocytes. This assumption is required to explain the measurements of kinetics of respiration, sarcoplasmic reticulum loading with calcium, and kinetics of ATP-sensitive potassium channels. To be able to analyze and estimate the role ... More
Binding of single nucleotides to H+-ATP synthases observed by fluorescence resonance energy transfer.
AuthorsSteigmiller S, Zimmermann B, Diez M, Börsch M, Gräber P
JournalBioelectrochemistry
PubMed ID15110252
F(0)F(1)-ATP synthases couple proton translocation with the synthesis of ATP from ADP and phosphate. The enzyme has three catalytic nucleotide binding sites, one on each beta-subunit; three non-catalytic binding sites are located mainly on each alpha-subunit. In order to observe substrate binding to the enzyme, the H(+)-ATP synthase from Escherichia ... More
Quantitative modeling of regular retinal microglia distribution.
Authors
JournalSci Rep
PubMed ID34811401
cGAS phase separation inhibits TREX1-mediated DNA degradation and enhances cytosolic DNA sensing.
Authors
JournalMol Cell
PubMed ID33606975
Alternating-site mechanism of kinesin-1 characterized by single-molecule FRET using fluorescent ATP analogues.