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Archives of Biochemistry and Biophysics Oct 2022In this study, we investigated whether modification of the carboxyl group with semicarbazide-enabled myoglobin (Mb) exhibits membrane-perturbing activity in...
In this study, we investigated whether modification of the carboxyl group with semicarbazide-enabled myoglobin (Mb) exhibits membrane-perturbing activity in physiological solutions. Mass spectrometry analysis showed that semicarbazide molecules were coupled to 19 of the 22 carboxyl groups in semicarbazide-modified Mb (SEM-Mb). Measurements of the absorption and circular dichroism spectra indicated that SEM-Mb lost its heme group and reduced the content of the α-helix structure in Mb. The microenvironment surrounding Trp residues in Mb changes after blocking negatively charged residues, as shown by fluorescence quenching studies. The results of the trifluoroethanol-induced structural transition indicated that SEM-Mb had higher structural flexibility than that of Mb. SEM-Mb, but not Mb, induced the permeability of bilayer membranes. Both proteins showed similar lipid-binding affinities. The conformation of SEM-Mb and Mb changed upon binding to lipid vesicles or a membrane-mimicking environment composed of SDS micelles, suggesting that membrane interaction modes differ. Unlike lipid-bound Mb, Trp residues in lipid-bound SEM-Mb are located at the protein-lipid interface. Altogether, our data indicate that modifying negatively charged groups relieves the structural constraints in Mb, consequently switching Mb structure to an active conformation that exhibits membrane-permeabilizing activity.
Topics: Circular Dichroism; Lipids; Myoglobin; Protein Conformation; Protein Conformation, alpha-Helical; Semicarbazides
PubMed: 35921901
DOI: 10.1016/j.abb.2022.109371 -
The Journal of Sports Medicine and... Dec 2023Monitoring muscle damage in athletes assists not only coaches to adjust the training workload but also medical staff to prevent injury. Measuring blood myoglobin...
BACKGROUND
Monitoring muscle damage in athletes assists not only coaches to adjust the training workload but also medical staff to prevent injury. Measuring blood myoglobin concentration can help evaluate muscle damage. The novel portable device utilized in this study allows for easy on-site measurement of myoglobin, providing real-time data on the player's muscle damage. This study investigated the relationship between external load (global positioning system parameters) and internal loads (myoglobin concentration and creatine kinase activity) in 15 male professional football players before and after a match.
METHODS
Whole blood samples from participants' fingertips were collected before the match (baseline) and at 2, 16, and 40 h after the match. Myoglobin concentrations were measured using the IA-100 compact immunoassay system. Creatine kinase concentrations were measured in a clinical laboratory, and match loads were monitored using a global positioning system device.
RESULTS
The mean myoglobin concentration was significantly higher at 2 h than at the other time points (P<0.05), and decreased to baseline levels within 16 h post-match. The mean creatine kinase concentration increased after the match but did not reach a significant level. Muscle damage monitored by myoglobin after football match-play was strongly associated with acceleration/deceleration metrics rather than the sprint/high-speed running distance.
CONCLUSIONS
Our findings indicate that myoglobin is a more sensitive marker of muscle damage than creatine kinase after football match-play. Monitoring myoglobin in athletes can aid in determining their recovery status from the previous training load and help practitioners manage the training load.
Topics: Humans; Male; Acceleration; Athletic Performance; Creatine Kinase; Deceleration; Geographic Information Systems; Muscles; Myoglobin; Soccer
PubMed: 37712927
DOI: 10.23736/S0022-4707.23.15203-0 -
Cells Mar 2022The maturation of hemeprotein dictates that they incorporate heme and become active, but knowledge of this essential cellular process remains incomplete. Studies on... (Review)
Review
The maturation of hemeprotein dictates that they incorporate heme and become active, but knowledge of this essential cellular process remains incomplete. Studies on chaperon Hsp90 has revealed that it drives functional heme maturation of inducible nitric oxide synthase (iNOS), soluble guanylate cyclase (sGC) hemoglobin (Hb) and myoglobin (Mb) along with other proteins including GAPDH, while globin heme maturations also need an active sGC. In all these cases, Hsp90 interacts with the heme-free or apo-protein and then drives the heme maturation by an ATP dependent process before dissociating from the heme-replete proteins, suggesting that it is a key player in such heme-insertion processes. As the studies on globin maturation also need an active sGC, it connects the globin maturation to the NO-sGC (Nitric oxide-sGC) signal pathway, thereby constituting a novel NO-sGC-Globin axis. Since many aggressive cancer cells make Hbβ/Mb to survive, the dependence of the globin maturation of cancer cells places the NO-sGC signal pathway in a new light for therapeutic intervention. Given the ATPase function of Hsp90 in heme-maturation of client hemeproteins, Hsp90 inhibitors often cause serious side effects and this can encourage the alternate use of sGC activators/stimulators in combination with specific Hsp90 inhibitors for better therapeutic intervention.
Topics: HSP90 Heat-Shock Proteins; Heme; Humans; Molecular Chaperones; Myoglobin; Nitric Oxide; Soluble Guanylyl Cyclase
PubMed: 35326427
DOI: 10.3390/cells11060976 -
Molecular Aspects of Medicine Apr 2022Antonini and Brunori's 1971 book "Hemoglobin and Myoglobin in Their Reactions with Ligands" was a truly remarkable publication that summarized almost 100 years of... (Review)
Review
Antonini and Brunori's 1971 book "Hemoglobin and Myoglobin in Their Reactions with Ligands" was a truly remarkable publication that summarized almost 100 years of research on O binding to these globins. Over the ensuing 50 years, ultra-fast laser photolysis techniques, high-resolution and time resolved X-ray crystallography, molecular dynamics simulations, and libraries of recombinant myoglobin (Mb) and hemoglobin (Hb) variants have provided structural interpretations of O binding to these proteins. The resultant mechanisms provide quantitative descriptions of the stereochemical factors that govern overall affinity, including proximal and distal steric restrictions that affect iron reactivity and favorable positive electrostatic interactions that preferentially stabilize bound O. The pathway for O uptake and release by Mb and subunits of Hb has been mapped by screening libraries of site-directed mutants in laser photolysis experiments. O enters mammalian Mb and the α and β subunits of human HbA through a channel created by upward and outward rotation of the distal His at the E7 helical position, is non-covalently captured in the interior of the distal cavity, and then internally forms a bond with the heme Fe(II) atom. O dissociation is governed by disruption of hydrogen bonding interactions with His (E7), breakage of the Fe(II)-O bond, and then competition between rebinding and escape through the E7-gate. The structural features that govern the rates of both the individual steps and overall reactions have been determined and provide the framework for: (1) defining the physiological functions of specific globins and their evolution; (2) understanding the clinical features of hemoglobinopathies; and (3) designing safer and more efficient acellular hemoglobin-based oxygen carriers (HBOCs) for transfusion therapy, organ preservation, and other commercially relevant O transport and storage processes.
Topics: Animals; Carbon Monoxide; Hemoglobins; Humans; Kinetics; Ligands; Mammals; Myoglobin; Oxygen
PubMed: 34544605
DOI: 10.1016/j.mam.2021.101024 -
Medicina Clinica Aug 2021The outbreak of novel coronavirus pneumonia 2019 (COVID-19) has caused millions of deaths worldwide. It is well documented that troponin predicts the prognosis of...
BACKGROUND
The outbreak of novel coronavirus pneumonia 2019 (COVID-19) has caused millions of deaths worldwide. It is well documented that troponin predicts the prognosis of patients. Myoglobin is not only an important marker of myocardial injury, but it indicates systemic muscle damage. However, its relationship with COVID-19 was rarely reported. The present study compared the predictive value of troponin and myoglobin on the final prognosis of COVID-19 patients by analyzing the clinical characteristics and serum levels of myoglobin and troponin in severe/critical COVID-19 patients.
METHODS
We enrolled 499 consecutive eligible hospitalized patients with severe/critical COVID-19 from February 14 to March 24, 2020 at Leishenshan Hospital, Wuhan, China. Clinical characteristics and laboratory data were collected and compared between the patients who died and survived. We analyzed the receiver operating characteristic curves of myoglobin and troponin. Then, the patients were divided into myo group, myo group, tro group, and tro group, and survival curves were analyzed. The prognostic predictable values of myoglobin and troponin were further analyzed using Cox multifactorial analysis.
RESULTS
Myoglobin and troponin were significantly elevated in the death group (134.4 [interquartile range (IQR) 24.80, 605] vs 38.02 [IQR 3.87, 11.73]ng/ml, p<0.001), and troponin was also significantly elevated in the death group (0.01 [IQR 0.01, 0.01] vs 0.04 [IQR 0.02, 0.15]ng/ml, p<0.001). The ROC curves demonstrated that the area under the curve when using myoglobin to predict patient death was 0.911, with a threshold of 1.17, which was equivalent to troponin. Kaplan-Meier survival analysis revealed a significantly lower survival curve in the myo group than the myo group. Multifactor Cox survival analysis showed that troponin was no longer significant (HR=0.98, 95% CI 0.92-1.03, p=0.507), but elevated myoglobin was an independent predictor of death in COVID-19 patients (HR=1.001, 95% CI 1.001-1.002, p<0.001). The analysis of the Cox model for predicting patient death and plotting decision curves suggested that the single factor myoglobin model was superior to troponin, and the predictive value of the multifactor model was superior to the single-factor analyses.
CONCLUSIONS
In severe/critical COVID-19 patients, myoglobin and troponin were predictors of mortality and the probability of conversion to critical illness, and myoglobin may be superior to troponin for predictive value.
Topics: Biomarkers; COVID-19; Humans; Myoglobin; Prognosis; Retrospective Studies; SARS-CoV-2; Troponin
PubMed: 33958143
DOI: 10.1016/j.medcli.2021.01.013 -
Physical Chemistry Chemical Physics :... Dec 2020All atom molecular dynamic modeling was applied in order to determine water molecule and electrolyte ion concentration profiles around and inside the myoglobin molecule...
All atom molecular dynamic modeling was applied in order to determine water molecule and electrolyte ion concentration profiles around and inside the myoglobin molecule at various pH values. Significant penetration of counter ions into the molecule was confirmed. The electric potential distribution within and outside the molecule was quantitatively described using the non-linear Poisson-Boltzmann (PB) approach. Using this model, calculations were performed, yielding the surface and zeta potential for various physicochemical parameters, comprising pH, the electric permittivity, the ion penetration depth and the protein volume fraction (crowding effect). The theoretical results were used for the interpretation of experimental data acquired under different ionic strengths and temperatures by electrophoretic mobility measurements. It is confirmed that the experimental data are adequately reflected for acidic pH values by the non-linear PB model where the nominal molecule charge was calculated from the H++ model. The deviations occurring for larger pH values were accounted for by considering additional non-electrostatic interactions stemming from the van der Waals and ion-induced dipole forces. In this way, it is both experimentally and theoretically confirmed that the effective charge of the myoglobin molecule in electrolyte solutions is considerably smaller than the nominal, structure-based, predicted charge. As a result, under physiological conditions prevailing, e.g. in skeletal muscles, the effective charge of the myoglobin molecule should practically vanish. One can expect that the approach developed in this work can be applied for predicting charging mechanisms of other protein molecules characterized by an analogous charge vs. pH characteristic, e.g., the SARS-CoV-2 virus spike proteins, and for soft particles with pH responsive characteristics.
Topics: Animals; Electrolytes; Horses; Hydrogen-Ion Concentration; Models, Chemical; Molecular Dynamics Simulation; Myoglobin; Osmolar Concentration; Solutions; Static Electricity
PubMed: 33206736
DOI: 10.1039/d0cp03771k -
Applied Spectroscopy Jun 2023To facilitate the design of an optical detection system for assessing rabbit meat quality, nine rabbits of different ages, weights, and varieties were used to collect...
To facilitate the design of an optical detection system for assessing rabbit meat quality, nine rabbits of different ages, weights, and varieties were used to collect optical coefficients, compositions, and microstructures from external oblique muscle (EOM) and internal oblique muscle (IOM) samples to research the relationship between them. The results show that rabbit age had a significant influence ( < 0.05) on the absorption coefficient (μ) and the proportion of myoglobin in IOM and EOM, and the older the rabbits are, the greater the μ and the proportion of myoglobin are. Weight also significantly ( < 0.05) influenced the muscle fiber cross-sectional area. The age and weight had a significant ( < 0.05) impact on the reduced scattering coefficient (μ'). The linear fitting results between the relative proportion of myoglobin and the μ showed that the higher the myoglobin content is, the greater the μ is. The linear fitting results between the cross-sectional area of muscle fiber and the μ' showed that the smaller the cross-sectional area of muscle fiber is, the greater the μ' is. These results will be helpful to intuitively understand the working principle of spectral technology in meat quality detection.
Topics: Animals; Rabbits; Myoglobin
PubMed: 36898965
DOI: 10.1177/00037028231166004 -
The Journal of Biological Chemistry 2021Proteins are the molecular machines of living systems. Their dynamics are an intrinsic part of their evolutionary selection in carrying out their biological functions.... (Review)
Review
Proteins are the molecular machines of living systems. Their dynamics are an intrinsic part of their evolutionary selection in carrying out their biological functions. Although the dynamics are more difficult to observe than a static, average structure, we are beginning to observe these dynamics and form sound mechanistic connections between structure, dynamics, and function. This progress is highlighted in case studies from myoglobin and adenylate kinase to the ribosome and molecular motors where these molecules are being probed with a multitude of techniques across many timescales. New approaches to time-resolved crystallography are allowing simple "movies" to be taken of proteins in action, and new methods of mapping the variations in cryo-electron microscopy are emerging to reveal a more complete description of life's machines. The results of these new methods are aided in their dissemination by continual improvements in curation and distribution by the Protein Data Bank and their partners around the world.
Topics: Adenylate Kinase; Animals; Databases, Protein; Humans; Models, Molecular; Myoglobin; Ribosomes; Structure-Activity Relationship
PubMed: 33961840
DOI: 10.1016/j.jbc.2021.100749 -
Physiological Reports May 2021Myoglobin is an important regulator of muscle and whole-body metabolism and exercise capacity. Caffeine, an activator of the calcium and cyclic AMP (cAMP)/protein kinase...
Myoglobin is an important regulator of muscle and whole-body metabolism and exercise capacity. Caffeine, an activator of the calcium and cyclic AMP (cAMP)/protein kinase A (PKA) pathway, enhances glucose uptake, fat oxidation, and mitochondrial biogenesis in skeletal muscle cells. However, no study has shown that caffeine increases the endogenous expression of myoglobin in muscle cells. Further, the molecular mechanism underlying the regulation of myoglobin expression remains unclear. Therefore, our aim was to investigate whether caffeine and activators of the calcium signaling and cAMP/PKA pathway increase the expression of myoglobin in L6 myotubes and whether the pathway mediates caffeine-induced myoglobin expression. Caffeine increased myoglobin expression and activated the cAMP/PKA pathway in L6 muscle cells. Additionally, a cAMP analog significantly increased myoglobin expression, whereas a ryanodine receptor agonist showed no significant effect. Finally, PKA inhibition significantly suppressed caffeine-induced myoglobin expression in L6 myotubes. These results suggest that caffeine increases myoglobin expression via the cAMP/PKA pathway in skeletal muscle cells.
Topics: Animals; Caffeine; Cell Line; Central Nervous System Stimulants; Cyclic AMP; Muscle Fibers, Skeletal; Myoglobin; Rats
PubMed: 33991466
DOI: 10.14814/phy2.14869 -
Archives of Biochemistry and Biophysics Jul 2020Hydropersulfides are reported to be good biological reductants, superior to thiols and akin to selenols. As such, they have been previously shown to reduce...
Hydropersulfides are reported to be good biological reductants, superior to thiols and akin to selenols. As such, they have been previously shown to reduce metalloproteins such as ferric myoglobin and ferric cytochrome c to their ferrous forms under conditions where little or no reduction from corresponding thiols is observed. Not surprisingly, the reduction of ferric myoglobin to ferrous myoglobin under aerobic conditions results in the generation of oxymyoglobin (dioxygen bound ferrous myoglobin). Previous studies have demonstrated that oxymyoglobin can also act as an oxidant with highly reducing species such as hydroxylamine and ascorbate. Considering the reducing properties of hydropersulfides, it is possible that they can also react with oxymyoglobin similarly to hydroxylamine or ascorbate. Herein, this reaction is examined and indeed hydropersulfides are found to react with oxymyoglobin similarly to other reducing species leading to a fleeting ferric myoglobin which is rapidly reduced to the ferrous form also by hydropersulfide.
Topics: Animals; Ascorbic Acid; Cattle; Horses; Hydroxylamine; Models, Chemical; Myoglobin; Oxidation-Reduction; Oxygen; Penicillamine; Sulfides
PubMed: 32360749
DOI: 10.1016/j.abb.2020.108391