Table 2.

Parameters derived from SAXS studies

Light scattering structural parameters for human β-cardiac 25-hep HMM (at 20 μM mavacamten and 50 μM para-nitroblebbistatin)
	DMSO	Para-nitroblebbistatin	Mavacamten
Molecular Mass (kDa)	365±18	363±14	366±18
Hydrodynamic radius (Å)	84.1±2.1	84.1±2.2	84.2±2.2
SAXS structural parameters of human β-cardiac 25-hep HMM based on Guinier Analysis (at 20 μM mavacamten and 50 μM para-nitroblebbistatin)
	DMSO	Para-nitroblebbistatin	Mavacamten
I(0) (cm−1)	0.093±0.003	0.04±0.01	0.055±0.015
Rg (Å)	119±1	102.5±1.5	102±5
q range (Å−1)	0.0048–0.0110	0.0048–0.0122	0.0059–0.0122
SAXS structural parameters of human β-cardiac 25-hep HMM based on P(r) Analysis (at 20 μM mavacamten and 50 μM para-nitroblebbistatin)
	DMSO	Para-nitroblebbistatin	Mavacamten
I(0) (cm−1)	0.09±0	0.04±0	0.06±0.02
Rg (Å)	139±4	124±10	114±8
Dmax(Å)	541±36	486±56	412±32
Porod volume (Å−3)	1.22e6	1.42e6	1.49e6
q range (Å−1)	0.0043–0.3522	0.0043–0.3522	0.0043–0.3522

25-hep HMM refers to heavy meromyosin containing the subfragment S1 and 25 heptad repeats of the S2-subfragment; I(0), zero-angle scattering intensity; R_g, radius of gyration; q, $=4\pi \mathbf{\text{sin}}\frac{\theta }{\lambda }$, 2θ is the scattering angle, and λ is the wavelength of the radiation; D_max, maximum dimension of the molecule; Porod volume, particle volume calculated as = 2π²I(0)/Q_i, where Q_i is the total scattered intensity [71]. Data reported are the mean±SEM from two experiments using two different protein preparations.