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Molecular Motion and Cardiac Muscle Motor Dynamics
Author(s) -
LANDESBERG AMIR,
LANDESBERG YOLANDA,
SIDEMAN SAMUEL,
TER KEURS HENK E.D.J.
Publication year - 2002
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2002.tb04561.x
Subject(s) - kinetics , myosin , actin , molecular motor , dynamics (music) , motility , dissociation (chemistry) , biophysics , protein filament , chemistry , receptor–ligand kinetics , myosin head , molecular dynamics , biology , biochemistry , microbiology and biotechnology , physics , myosin light chain kinase , computational chemistry , quantum mechanics , acoustics
A bstract : This paper reports on the kinetics of molecular motion in cardiac (and skeletal) muscles, studied by image analysis of the motility assay of an isolated actin filament sliding over isolated myosin heads that perform as linear motors. Image analysis allows us to study the dynamics of the crossbridges (Xbs) formed by the interactions between the actin molecule and the myosin heads, and to explore the rate kinetics of the interactions between the two. A most significant result pertains to the identification and characterization of two kinds of kinetics involved in Xb dynamics. The analysis of the acquired images suggests that Xb dynamics is determined by two distinctive kinetic mechanisms: fast physical kinetics that relates to the actin‐myosin Xb attachment and detachment cycle and a process that is orders of magnitude slower in biochemical kinetics that relates to the reactions of nucleotide binding and dissociation.