Fig. 6: Mechanical stability of a partial α-actinin 1 homo-dimer of SR2–SR3:SR2–SR3 under shear-stretching force geometry. | Nature Communications

Fig. 6: Mechanical stability of a partial α-actinin 1 homo-dimer of SR2–SR3:SR2–SR3 under shear-stretching force geometry.

From: Multi-domain interaction mediated strength-building in human α-actinin dimers unveiled by direct single-molecule quantification

Fig. 6

a The illustration of the single-molecule construct and experimental design for quantifying the mechanical stability of the partial dimer. b Representative force–bead height curves of partial α-actinin 1 rod homo-dimer of SR2–SR3:SR2–SR3 under shear-stretching force geometry during force-increase scans (1 pN s−1, top panel) and force-decrease scans (−0.1 pN s−1, bottom panel). The rupture and re-dimerization events are noted by the red arrow and dark gray arrows, respectively. The unfolding and refolding events of the domains are noted by gray upward arrows and downward arrows, respectively. c Representative time–bead height curves of the partial dimer at forces in a range of 2.0 pN to 3.4 pN in 20 s time window. The red lines are the step-wise fitting of the raw data in gray by hidden Markov model. The right panel shows the normalized bead height distributions at each force obtained by 200 seconds data recording. The blue lines are gaussian fitting of the distributions. d The force-dependent rupture probability (red) and re-dimerization probability (blue). The symbols are experimental data obtained. The blue line is obtained by fitting with \({P}_{{{{{{{\rm{re-dimerization}}}}}}}}(F)=1/\left(\exp \frac{(F-{F}_{c})\Delta x}{{k}_{{{{{{{\rm{B}}}}}}}}T}+1\right)\); the red line is obtained by fitting with \({P}_{{{{{{{\rm{rupture}}}}}}}}(F)=1-{P}_{{{{{{{\rm{re-dimerization}}}}}}}}(F)\). e The time evolution of the rupture probability at each force, from which the characteristic lifetime of the corresponding force was obtained by exponential fitting with \(P(t)=1-\exp (-\frac{t}{\tau })\). f The resulting force-dependent lifetime of the partial dimer. The dwell times of the dimer at each force were plotted in gray hollow symbols, and the characteristic lifetime of each force was plotted in solid symbols. The blue dashed line is Bell model fitting curve of the blue data set. Source data are provided as a Source Data file.

Back to article page