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The two mutations of actin-myosin interface and their effect on the dynamics, structures, and functions of skeletal muscle actin

Sadat Mohajer F, Parvizpour S, Razmara J, Shahir Shamsir M

J Biomol Struct Dyn, 2019 Feb;37(2):372-382.
PMID: 29338614 DOI: 10.1080/07391102.2018.1427630

Congenital myopathy is a broad category of muscular diseases with symptoms appearing at the time of birth. One type of congenital myopathy is Congenital Fiber Type Disproportion (CFTD), a severely debilitating disease. The G48D and G48C mutations in the D-loop and the actin-myosin interface are the two causes of CFTD. These mutations have been shown to significantly affect the structure and function of muscle fibers. To the author's knowledge, the effects of these mutations have not yet been studied. In this work, the power stroke structure of the head domain of myosin and the wild and mutated types of actin were modeled. Then, a MD simulation was run for the modeled structures to study the effects of these mutations on the structure, function, and molecular dynamics of actin. The wild and mutated actins docked with myosin showed differences in hydrogen bonding patterns, free binding energies, and hydrogen bond occupation frequencies. The G48D and G48C mutations significantly impacted the conformation of D-loops because of their larger size compared to Glycine and their ability to interfere with the polarity or hydrophobicity of this neutralized and hydrophobic loop. Therefore, the mutated loops were unable to fit properly into the hydrophobic groove of the adjacent G-actin. The abnormal structure of D-loops seems to result in the abnormal assembly of F-actins, giving rise to the symptoms of CFTD. It was also noted that G48C and G48D did not form hydrogen bonds with myosin in the residue 48 location. Nevertheless, in this case, muscles are unable to contract properly due to muscle atrophy.

Matched MeSH terms: Myosins/genetics*; Myosins/chemistry*
[CLINICAL EFFICACY OF A REPRESENTATIVE OF A NEW CLASS OF INOTROPIC AGENTS - THE DIRECT ACTIVATOR OF MYOSIN OF CARDIOMYOCYTES OMECAMTIV MECARBIL IN HEART FAILURE WITH A REDUCED EJECTION FRACTION]

Kravchenko I, Rudyk I, Medentseva O

Georgian Med News, 2021 Sep.
PMID: 34628401

Over the past decades, there has been an active scientific search for drugs that can increase myocardial contractility and improve the course of heart failure. Omecamtiv Mecarbil, a drug from the group of cardiac myosin activators, heads the list of applicants for clinical use. The article presents the results of several randomized clinical trials which studied the efficacy and safety of Omecamtiv Mecarbil in heart failure: ATOMIC-AHF, COSMIC-HF and GALACTIC-HF. ATOMIC-AHF showed a tendency to reduce the risk of developing supraventricular and ventricular arrhythmias in heart failure. COSMIC-HF has proven the ability of Omecamtiv Mecarbil to improve the quality of life of patients with heart failure. GALACTIC-HF may be a turning point in the medical treatment of heart failure. For the first time, clinical evidence of the ability of the selective cardiac myosin activator Omecamtiv Mecarbil to improve myocardial contractile function, reduce the severity of symptoms of heart failure and reduce the risk of cardiovascular death was obtained.

Matched MeSH terms: Myosins
Fulltext Effect of polydextrose on physicochemical properties of threadfin bream (Nemipterus spp) surimi during frozen storage

Nopianti R, Huda N, Ismail N, Ariffin F, Easa AM

J Food Sci Technol, 2013 Aug;50(4):739-46.
PMID: 24425976 DOI: 10.1007/s13197-011-0394-0

Physicochemical properties of threadfin bream surimi with different levels of polydextrose (3%, 6%, 9% and 12%), raw surimi, raw surimi with addition sodium tripolyphosphate and commercial surimi (sucrose) during 6 months of frozen storage were investigated. The analyses included the measurement of Ca(2+)-ATPase, sulfhydryl contents, protein solubility, sodium dodecyl sulfate polyacrylamide gel electrophoresis, differential scanning calorimetry and scanning electron microscopy. The Ca(2+)-ATPase, sulfhydryl content and protein solubility levels added with 3%, 6%, 9% and 12% polydextrose can be maintained until the 6 months of storage by 47.33%, 41.60% and 51.41%, respectively. Differential scanning calorimetry showed decreases in thermal stabilization of myosin with regard to transition termperature. Analysis by scanning electron microscopy demonstrated that the number of pores formed was increased after storage. This study suggested that surimi stored with the polydextrose as a cryoprotectant was able to maintain physicochemical of surimi better compared to raw surimi with no additives or raw surimi with sodium tripolyphosphate.

Matched MeSH terms: Myosins
Fulltext Analysis of MYO1H single nucleotide polymorphism in class iii malocclusion with mandibular prognathism: a preliminary study

Siti Nazirah Yahya, Nurul Syafiqah Abdul Razak, Noraini Abu Bakar, Khairani Idah Mokhtar, Azrul Fazwan Kharuddin

International Medical Journal Malaysia, 2017;16(21):13-13.
MyJurnal

Evidence suggests that several genes; including MYO1H, play an important role in the
etiology of Class III malocclusion. Single nucleotide polymorphism (SNP) in marker rs10850110 (locus
12q24.11) within MYO1H gene has been associated with the incidence of mandibular prognathism
(MP). MYO is a class 1 myosin that is responsible for the synthesis of Matrilin-1; an important
protein involved in the formation of cartilage's extracellular matrix, hence is implicated in the
formation of mandibular condyle cartilage. This study aimed to detect the presence of MYO1H
(rs10850110) SNP and to determine its genotype and allele distribution in MP patient in the local
population. (Copied from article).

Matched MeSH terms: Myosins
Fulltext Bioactive Proteins in Channa striata Promote Wound Healing through Angiogenesis and Cell Proliferation

Kwan SH, Abdul Aziz NHK, Ismail MN

Protein Pept Lett, 2020;27(1):48-59.
PMID: 31362651 DOI: 10.2174/0929866526666190730121711

BACKGROUND: Channa striata are speculated to contain bioactive proteins with the ability to enhancing wound healing. It is commonly consumed after surgery for a faster recovery of the wound.
OBJECTIVE: To identify the bioactive proteins and evaluate their ability in cell proliferation and angiogenesis promotion.
MATERIAL AND METHODS: Freeze-Dried Water Extracts (FDWE) and Spray-Dried Water Extracts (SDWE) of C. striata were tested with MTT assay using EA.hy926 endothelial cell line and ex-vivo aortic ring assay. Later the proteins were fractionated and analysed using an LC-QTOF mass spectrometer. The data generated were matched with human gene database for protein similarity and pathway identification.
RESULTS: Both samples have shown positive cell proliferation and pro-angiogenic activity. Four essential proteins/genes were identified, which are collagen type XI, actin 1, myosin light chain and myosin heavy chain. The pathways discovered that related to these proteins are integrin pathway, Slit-Robo signalling pathway and immune response C-C Chemokine Receptor-3 signalling pathway in eosinophils, which contribute towards wound healing mechanism.
CONCLUSIONS: The results presented have demonstrated that C. striata FDWE and SDWE protein fractions contain bioactive proteins that are highly similar to human proteins and thus could be involved in the wound healing process via specific biological pathways.

Matched MeSH terms: Myosins/chemistry
Derivation of cochlea hair cell for in vitro expansion and characterization

Ibnubaidah MA, Chua KH, Mazita A, Azida ZN, Aminuddin BS, Ruszymah BH, et al.

Med J Malaysia, 2008 Jul;63 Suppl A:115-6.
PMID: 19025012

A potential cure for hearing loss would be to regenerate hair cells by stimulating cells of the damaged inner ear sensory epithelia to proliferate and differentiate into hair cells. Here, we investigated the possibility to isolate, culture-expand and characterize the cells from the cochlea membrane of adult mice. Our results showed that the cultured cells isolated from mouse cochlea membrane were heterogenous in nature. Morphologically there were epithelial like cells, hair cell like, nerve cell like and fibroblastic cells observed in the culture. The cultured cells were immunopositive for specific hair cell markers including Myosin 7a, Calretinin and Espin.

Matched MeSH terms: Myosins