A Potent Fluorescent Reversible-Covalent Inhibitor of Cardiac Muscle Contraction

TY - JOUR

T1 - A Potent Fluorescent Reversible-Covalent Inhibitor of Cardiac Muscle Contraction

AU - Cai, Fangze

AU - Kampourakis, Thomas

AU - Klein, Brittney A.

AU - Sykes, Brian D.

N1 - Funding Information: Financial support from University of Alberta Faculty of Medicine Transitional Program (B.D.S.), Heart and Stroke foundation of Canada (G-14-0005884, B.D.S.), and British Heart Foundation (Fellowship FS/16/3/31887, T.K.), and University of Alberta Faculty of Medicine Motyl Graduate Studentship in Cardiac Science (F.C.). The authors thank Jack Moore for mass spectrometry experiments; Bridgette Hartley and Olivier Julien for their assistance with fluorescence experiments. Publisher Copyright: © 2021 American Chemical Society. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/9/9

Y1 - 2021/9/9

N2 - Compounds that directly modulate the response of the cardiac sarcomere have potential in the treatment of cardiac disease. While a number of sarcomere activators have been discovered and extensively studied, very few inhibitors have been identified. We report a potent cardiac sarcomere inhibitor, DN-F01, targeting the cardiac muscle thin filament protein troponin complex. Functional studies show that DN-F01 has a strong inhibitory calcium-dependent effect on cardiac myofibrillar ATPase activity with an IC50 value of 11 ± 4 nmol/L. DN-F01 is shown to bind to a cardiac troponin C-troponin I chimera (cChimera) with a KD of μ50 nM using fluorescence spectroscopy, indicating that troponin is the likely target for DN-F01. NMR titrations of DN-F01 to C35S and A-Cys cChimera show covalent and noncovalent binding of DN-F01 bound to the calcium-saturated cChimera.

AB - Compounds that directly modulate the response of the cardiac sarcomere have potential in the treatment of cardiac disease. While a number of sarcomere activators have been discovered and extensively studied, very few inhibitors have been identified. We report a potent cardiac sarcomere inhibitor, DN-F01, targeting the cardiac muscle thin filament protein troponin complex. Functional studies show that DN-F01 has a strong inhibitory calcium-dependent effect on cardiac myofibrillar ATPase activity with an IC50 value of 11 ± 4 nmol/L. DN-F01 is shown to bind to a cardiac troponin C-troponin I chimera (cChimera) with a KD of μ50 nM using fluorescence spectroscopy, indicating that troponin is the likely target for DN-F01. NMR titrations of DN-F01 to C35S and A-Cys cChimera show covalent and noncovalent binding of DN-F01 bound to the calcium-saturated cChimera.

KW - cardiac

KW - inhibitor

KW - sarcomere

KW - troponin

UR - http://www.scopus.com/inward/record.url?scp=85114428072&partnerID=8YFLogxK

U2 - 10.1021/acsmedchemlett.1c00366

DO - 10.1021/acsmedchemlett.1c00366

M3 - Article

AN - SCOPUS:85114428072

SN - 1948-5875

VL - 12

SP - 1503

EP - 1507

JO - Acs Medicinal Chemistry Letters

JF - Acs Medicinal Chemistry Letters

IS - 9

ER -