Correction to Troponin C Mutations Partially Stabilize the Active State

Addition/Correction Cite This: Biochemistry 2017, 56, 5966-5966

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Correction to Troponin C Mutations Partially Stabilize the Active State of Regulated Actin and Fully Stabilize the Active State When Paired with Δ14 TnT Tamatha Baxley, Dylan Johnson, Jose R. Pinto, and Joseph M. Chalovich* Biochemistry 2017, 56 (23), 2928−2937. DOI: 10.1021/acs.biochem.6b01092 The corrected version of Figure 6 appears below.

Figure 6. Rate of binding of S1 to pyrene-labeled actin filaments containing tropomyosin and troponin in the absence of ATP. In the experiment, 4 μM pyrene-actin (40% labeled), 0.86 μM tropomyosin, and 2 μM troponin were rapidly mixed with 0.4 μM myosin S1 in a buffer containing 152 mM KCl, 2 mM EGTA, 20 mM MOPS buffer (pH 7), 4 mM MgCl2, and 1 mM dithiothreitol at 10 °C. (A) Low Ca2+ concentration: curve 1, wild type, kapp = 0.10 ± 0.01 s−1; curve 2, A8V, kapp = 0.12 ± 0.02 s−1; curve 3, A8V TnC and Δ14 TnT, kapp = 0.5 ± 0.02 s−1. Solid lines are monoexponential fits to each curve. (B) High Ca2+ concentration : curve 1, wild type, kapp = 0.77 ± 0.14 s−1; curve 2, A8V, kapp = 0.70 ± 0.05 s−1; curve 3, A8V TnC and Δ14 TnT, kapp = 0.91 ± 0.15 s−1. (C) Fraction of the maximum effect on the binding kinetics at a low Ca2+ concentration vs the free troponin concentration: wild type (○) and A8V (□). The highest point corresponds to the conditions used for the main figure. The fitted curve is for a dissociation constant of 0.12 μM.

Received: September 26, 2017 Published: October 24, 2017 © 2017 American Chemical Society

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DOI: 10.1021/acs.biochem.7b00963 Biochemistry 2017, 56, 5966−5966