Small angle X-ray diffraction as a tool for structural characterization of muscle disease

W Ma, TC Irving - International Journal of Molecular Sciences, 2022 - mdpi.com
Small angle X-ray fiber diffraction is the method of choice for obtaining molecular level
structural information from striated muscle fibers under hydrated physiological conditions …

Titin force in muscle cells alters lattice order, thick and thin filament protein formation

AL Hessel, W Ma, N Mazara, PE Rice, D Nissen… - Proceedings of the …, 2022 - pnas.org
Skeletal muscle force production is increased at longer compared to shorter muscle lengths
because of length-dependent priming of thick filament proteins in the contractile unit before …

Cardiac myosin filaments are directly regulated by calcium

W Ma, S Nag, H Gong, L Qi, TC Irving - Journal of General Physiology, 2022 - rupress.org
Classically, striated muscle contraction is initiated by calcium (Ca2+)-dependent structural
changes in regulatory proteins on actin-containing thin filaments, which allow the binding of …

The structural OFF and ON states of myosin can be decoupled from the biochemical super-and disordered-relaxed states

VP Jani, T Song, C Gao, H Gong, S Sadayappan… - PNAS …, 2024 - academic.oup.com
There is a growing awareness that both thick-filament and classical thin-filament regulations
play central roles in modulating muscle contraction. Myosin ATPase assays have …

Cardiac troponin T N-domain variant destabilizes the actin interface resulting in disturbed myofilament function

M Landim-Vieira, W Ma, T Song… - Proceedings of the …, 2023 - pnas.org
Missense variant Ile79Asn in human cardiac troponin T (cTnT-I79N) has been associated
with hypertrophic cardiomyopathy and sudden cardiac arrest in juveniles. cTnT-I79N is …

Myosin in autoinhibited off state(s), stabilized by mavacamten, can be recruited in response to inotropic interventions

W Ma, CL Del Rio, L Qi, M Prodanovic… - Proceedings of the …, 2024 - pnas.org
Mavacamten is a FDA-approved small-molecule therapeutic designed to regulate cardiac
function at the sarcomere level by selectively but reversibly inhibiting the enzymatic activity …

The structural and functional integrities of porcine myocardium are mostly preserved by cryopreservation

W Ma, KH Lee, CE Delligatti, MT Davis… - Journal of General …, 2023 - rupress.org
Structural and functional studies of heart muscle are important to gain insights into the
physiological bases of cardiac muscle contraction and the pathological bases of heart …

[HTML][HTML] EMD-57033 augments the contractility in porcine myocardium by promoting the activation of myosin in thick filaments

V Jani, W Qian, S Yuan, T Irving, W Ma - International Journal of …, 2022 - mdpi.com
Sufficient cardiac contractility is necessary to ensure the sufficient cardiac output to provide
an adequate end-organ perfusion. Inadequate cardiac output and the diminished perfusion …

[HTML][HTML] Substrate mechanics unveil early structural and functional pathology in iPSC micro-tissue models of hypertrophic cardiomyopathy

J Guo, H Jiang, D Schuftan, JD Moreno, G Ramahdita… - Iscience, 2024 - cell.com
Hypertension is a major cause of morbidity and mortality in patients with hypertrophic
cardiomyopathy (HCM), suggesting a potential role for mechanics in HCM pathogenesis …

The distinctive mechanical and structural signatures of residual force enhancement in myofibers

AL Hessel, MN Kuehn, BM Palmer, D Nissen… - Proceedings of the …, 2024 - pnas.org
In muscle, titin proteins connect myofilaments together and are thought to be critical for
contraction, especially during residual force enhancement (RFE) when steady-state force is …