Table I.

Summary of in vitro motility and laser trap data

Heavy chain constructLight chain compositionVelocityUnitary displacementDisplacement duration
μm s−1nmms
M5HMMCalmodulin0.41 ± 0.06a21 ± 2 (6)120 ± 12 (6)
M5HMMCalmodulin/LC1sa0.30 ± 0.0718 ± 2 (5)111 ± 31 (5)
M5HMM(tag)Calmodulin0.46 ± 0.04a18 ± 2 (5)100 ± 13 (14)
M5HMM(tag)Calmodulin/LC1sa0.26 ± 0.0624 ± 2 (6)138 ± 21 (5)
  • a p < 0.01 when the effects of light chain composition were compared for a given heavy chain construct.

  • The in vitro motility values are means ± SD at 25 mM KCl. The unitary displacement values are means ± SEM. The quantities in parentheses represent the number of MV histograms (i.e., data sets) that contribute to the mean. LC1sa refers to the nonmuscle essential light chain.