Divalent ions as mediators of carbonylation in cardiac myosin binding protein C

Christina Bergonzo1, Baikuntha Aryal2, V Ashutosh Rao2

  • 1Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, the University of Maryland, 9600 Gudelsky Way, Rockville, MD, 20850, USA.

Insights

Chemotherapy drug toxicity may stem from metal-induced damage to cardiac myosin binding protein C (cMyBP-C). This study reveals metal ions near cMyBP-C may disrupt its actin binding, impacting heart function.

Area of Science:

  • Biochemistry
  • Cardiovascular Science
  • Computational Biology

Background:

  • Chemotherapeutic drug efficacy is often limited by off-pathway toxicities.
  • Cardiac myosin binding protein C (cMyBP-C) in heart tissue is a potential target for metal-catalyzed oxidative damage.
  • Previous studies link metal ions and reactive oxygen species to protein carbonylation, altering protein structure and function.

Purpose of the Study:

  • To investigate the ion environment around the C0 and C1 subunits of cMyBP-C.
  • To explore the relationship between metal ions, protein carbonylation, and actin-cMyBP-C binding.
  • To understand the molecular mechanisms underlying chemotherapy-induced cardiotoxicity.

Main Methods:

  • Long timescale all-atom molecular dynamics simulations were employed.
  • The study focused on the C0 and C1 subunits of cMyBP-C, crucial for actin binding.
  • Analysis of ion localization and its correlation with carbonylation-prone amino acid residues.

Main Results:

  • Divalent cations were found to be co-localized with amino acid residues susceptible to carbonylation within cMyBP-C.
  • Carbonylation of these specific residues can lead to interruptions in the binding between actin and cMyBP-C.
  • This suggests a potential mechanism for metal-induced cardiotoxicity.

Conclusions:

  • Metal ion accumulation near critical binding sites on cMyBP-C is implicated in chemotherapy-related cardiotoxicity.
  • Site-specific carbonylation of cMyBP-C by metal ions can disrupt its function in cardiac muscle.
  • These findings highlight the need for strategies to mitigate metal-induced damage during chemotherapy.

Related Concept Videos

Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.2K
Overview of Myosin Structure and Function01:15

Overview of Myosin Structure and Function

Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X)  have been well...
4.5K
The Role of Actin and Myosin in Non-muscle Cells01:10

The Role of Actin and Myosin in Non-muscle Cells

Actin and myosin or actomyosin filaments also play a significant role in cells other than those involved in muscle contraction (which occurs within the sarcomere of muscle cells). The mechanism of non-muscle cell contractile bundles was first observed in Dictyostelium and Acanthamoeba. In non-muscle cells, two bundles are commonly found: stress fibers and actomyosin adherence belts. These contractile bundles are smaller and less organized than the ones found in muscle cells. They  are held...
3.5K
Carbocations02:10

Carbocations

Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...
11.3K
Cross-bridge Cycle01:26

Cross-bridge Cycle

As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
117.7K
Metal-Ligand Bonds02:51

Metal-Ligand Bonds

The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
21.0K