Key result
In the absence of nucleotide, heavy meromyosin binds 100-1000-fold more strongly to F-actin than does subfragment 1, indicating both heads of HMM bind to F-actin.
Population
In vitro model using F-actin, heavy meromyosin (HMM), and myosin subfragment 1 (S-1)
Comparison
Heavy meromyosin binding under varying ionic… vs Myosin subfragment 1 binding under identical…
Design
Preclinical
Authors
Loading...
Supports double-headed binding in rigor; leaves open nucleotide effects on cardiac cross-bridge kinetics.
Effect estimate: 100-1000-fold stronger binding
The study demonstrates that the second head of heavy meromyosin contributes significantly to F-actin binding only in the absence of nucleotides, providing mechanistic insights into muscle contraction.
Lois E. Greene (1981) studied this question. Heavy meromyosin (HMM) vs. Myosin subfragment 1 (S-1) was evaluated on Binding to F-actin (100-1000-fold stronger binding). In the absence of nucleotide, heavy meromyosin binds 100-1000-fold more strongly to F-actin than does subfragment 1, indicating both heads of HMM bind to F-actin.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: