In order to understand how the dilated cardiomyopathy-causing Glu40Lys mutation in TM affects actomyosin interactions, thin filaments have been reconstituted in muscle ghost fibers by incorporation of labeled Cys707 of myosin subfragment-1 and Cys374 of actin with fluorescent probe 1.5-IAEDANS and α-tropomyosin (wild-type or Glu40Lys mutant).
Five Tm mutations were chosen for this study: the hypertrophic cardiomyopathy (HCM) mutations E62Q, E180G, and L185R and the dilated cardiomyopathy (DCM) mutations E40K and E54K.