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The Analyst May 2024A forced, damped harmonic oscillator model for gas-phase ion parking using single-frequency resonance excitation is described and applied to high-mass ions of relevance...
A forced, damped harmonic oscillator model for gas-phase ion parking using single-frequency resonance excitation is described and applied to high-mass ions of relevance to native mass spectrometry. Experimental data are provided to illustrate key findings revealed by the modelling. These include: (i) ion secular frequency spacings between adjacent charge states of a given protein are essentially constant and decrease with the mass of the protein (ii) the mechanism for ion parking of high mass ions is the separation of the ion clouds of the oppositely-charged ions with much less influence from an increase in the relative ion velocity due to resonance excitation, (iii) the size of the parked ion cloud ultimately limits ion parking at high / ratio, and (iv) the extent of ion parking of off-target ions is highly sensitive to the bath gas pressure in the ion trap. The model is applied to ions of 17 kDa, 467 kDa, and 2 MDa while experimental data are also provided for ions of horse skeletal muscle myoglobin (≈17 kDa) and β-galactosidase (≈467 kDa). The model predicts and data show that it is possible to effect ion parking on a 17 kDa protein to the 1 charge state under trapping conditions that are readily accessible with commercially available ion traps. It is also possible to park β-galactosidase efficiently to a roughly equivalent / ratio (, the 26 charge state) under the same trapping conditions. However, as charge states decrease, analyte ion cloud sizes become too large to allow for efficient ion trapping. The model allows for a semi-quantitative prediction of ion trapping performance as a function of ion trapping, resonance excitation, and pressure conditions.
PubMed: 38600834
DOI: 10.1039/d4an00242c -
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 -
Frontiers in Immunology 2023The novel coronavirus disease 2019 (COVID-19) presents with complex pathophysiological effects in various organ systems. Following the COVID-19, there are shifts in...
BACKGROUND
The novel coronavirus disease 2019 (COVID-19) presents with complex pathophysiological effects in various organ systems. Following the COVID-19, there are shifts in biomarker and cytokine equilibrium associated with altered physiological processes arising from viral damage or aggressive immunological response. We hypothesized that high daily dose methylprednisolone improved the injury biomarkers and serum cytokine profiles in COVID-19 patients.
METHODS
Injury biomarker and cytokine analysis was performed on 50 SARS-Cov-2 negative controls and 101 hospitalized severe COVID-19 patients: 49 methylprednisolone-treated (MP group) and 52 placebo-treated serum samples. Samples from the treated groups collected on days D1 (pre-treatment) all the groups, D7 (2 days after ending therapy) and D14 were analyzed. Luminex assay quantified the biomarkers HMGB1, FABP3, myoglobin, troponin I and NTproBNP. Immune mediators (CXCL8, CCL2, CXCL9, CXCL10, TNF, IFN-γ, IL-17A, IL-12p70, IL-10, IL-6, IL-4, IL-2, and IL-1β) were quantified using cytometric bead array.
RESULTS
At pretreatment, the two treatment groups were comparable demographically. At pre-treatment (D1), injury biomarkers (HMGB1, TnI, myoglobin and FABP3) were distinctly elevated. At D7, HMGB1 was significantly higher in the MP group (p=0.0448) compared to the placebo group, while HMGB1 in the placebo group diminished significantly by D14 (p=0.0115). Compared to healthy control samples, several immune mediators (IL-17A, IL-6, IL-10, MIG, MCP-1, and IP-10) were considerably elevated at baseline (all p≤0.05). At D7, MIG and IP-10 of the MP-group were significantly lower than in the placebo-group (p=0.0431, p=0.0069, respectively). Longitudinally, IL-2 (MP-group) and IL-17A (placebo-group) had increased significantly by D14. In placebo group, IL-2 and IL-17A continuously increased, as IL-12p70, IL-10 and IP-10 steadily decreased during follow-up. The MP treated group had IL-2, IFN-γ, IL-17A and IL-12p70 progressively increase while IL-1β and IL-10 gradually decreased towards D14. Moderate to strong positive correlations between chemokines and cytokines were observed on D7 and D14.
CONCLUSION
These findings suggest MP treatment could ameliorate levels of myoglobin and FABP3, but appeared to have no impact on HMGB1, TnI and NTproBNP. In addition, methylprednisolone relieves the COVID-19 induced inflammatory response by diminishing MIG and IP-10 levels. Overall, corticosteroid (methylprednisolone) use in COVID-19 management influences the immunological molecule and injury biomarker profile in COVID-19 patients.
Topics: Humans; Cytokines; Interleukin-10; HMGB1 Protein; Interleukin-17; Methylprednisolone; Chemokine CXCL10; Interleukin-2; Interleukin-6; Myoglobin; COVID-19; SARS-CoV-2; Interleukin-12
PubMed: 37662953
DOI: 10.3389/fimmu.2023.1229611 -
Biochemistry Sep 2023Proteins have undergone evolutionary processes to achieve optimal stability, increased functionality, and novel functions. Comparative analysis of existent and ancestral...
Proteins have undergone evolutionary processes to achieve optimal stability, increased functionality, and novel functions. Comparative analysis of existent and ancestral proteins provides insights into the factors that influence protein stability and function. Ancestral sequence reconstruction allows us to deduce the amino acid sequences of ancestral proteins. Here, we present the structural and functional characteristics of an ancestral protein, AncMH, reconstructed to be the last common ancestor of hemoglobins and myoglobins. Our findings reveal that AncMH harbors heme and that the heme binds oxygen. Furthermore, we demonstrate that the ferrous heme in AncMH is pentacoordinated, similar to that of human adult hemoglobin and horse myoglobin. A detailed comparison of the heme pocket structure indicates that the heme pocket in AncMH is more similar to that of hemoglobin than that of myoglobin. However, the autoxidation of AncMH is faster than that of both hemoglobin and myoglobin. Collectively, our results suggest that ancestral proteins of hemoglobins and myoglobins evolved in steps, including the hexa- to pentacoordination transition, followed by stabilization of the oxygen-bound form.
Topics: Adult; Humans; Animals; Horses; Globins; Heme; Myoglobin; Amino Acid Sequence; Oxygen
PubMed: 37647623
DOI: 10.1021/acs.biochem.3c00203 -
Journal of Inorganic Biochemistry Aug 2023Kinetic and structural investigations of the flavohemoglobin-type NO dioxygenase have suggested critical roles for transient Fe(III)O complex formation and O-forced...
Kinetic and structural investigations of the flavohemoglobin-type NO dioxygenase have suggested critical roles for transient Fe(III)O complex formation and O-forced movements affecting hydride transfer to the FAD cofactor and electron-transfer to the Fe(III)O complex. Stark-effect theory together with structural models and dipole and internal electrostatic field determinations provided a semi-quantitative spectroscopic method for investigating the proposed Fe(III)O complex and O-forced movements. Deoxygenation of the enzyme causes Stark effects on the ferric heme Soret and charge-transfer bands revealing the Fe(III)O complex. Deoxygenation also elicits Stark effects on the FAD that expose forces and motions that create a more restricted NADH access to FAD for hydride transfer and switch electron-transfer off. Glucose also forces the enzyme toward an off state. Amino acid substitutions at the B10, E7, E11, G8, D5, and F7 positions influence the Stark effects of O on resting heme spin states and FAD consistent with the proposed roles of the side chains in the enzyme mechanism. Deoxygenation of ferric myoglobin and hemoglobin A also induces Stark effects on the hemes suggesting a common 'oxy-met' state. The ferric myoglobin and hemoglobin heme spectra are also glucose-responsive. A conserved glucose or glucose-6-phosphate binding site is found bridging the BC-corner and G-helix in flavohemoglobin and myoglobin suggesting novel allosteric effector roles for glucose or glucose-6-phosphate in the NO dioxygenase and O storage functions. The results support the proposed roles of a ferric O intermediate and protein motions in regulating electron-transfer during NO dioxygenase turnover.
Topics: Iron; Myoglobin; Oxygen; Electrons; Glucose-6-Phosphate; Heme; Nitric Oxide
PubMed: 37229820
DOI: 10.1016/j.jinorgbio.2023.112257 -
The Journal of Physiology Mar 2024Myoglobin (Mb) plays an important role at rest and during exercise as a reservoir of oxygen and has been suggested to regulate NO bioavailability under hypoxic/acidic...
Myoglobin (Mb) plays an important role at rest and during exercise as a reservoir of oxygen and has been suggested to regulate NO bioavailability under hypoxic/acidic conditions. However, its ultimate role during exercise is still a subject of debate. We aimed to study the effect of Mb deficiency on maximal oxygen uptake ( ) and exercise performance in myoglobin knockout mice (Mb ) when compared to control mice (Mb ). Furthermore, we also studied NO bioavailability, assessed as nitrite (NO ) and nitrate (NO ) in the heart, locomotory muscle and in plasma, at rest and during exercise at exhaustion both in Mb and in Mb mice. The mice performed maximal running incremental exercise on a treadmill with whole-body gas exchange measurements. The Mb mice had lower body mass, heart and hind limb muscle mass (P < 0.001). Mb mice had significantly reduced maximal running performance (P < 0.001). expressed in ml min in Mb mice was 37% lower than in Mb mice (P < 0.001) and 13% lower when expressed in ml min kg body mass (P = 0.001). Additionally, Mb mice had significantly lower plasma, heart and locomotory muscle NO levels at rest. During exercise NO increased significantly in the heart and locomotory muscles of Mb and Mb mice, whereas no significant changes in NO were found in plasma. Our study showed that, contrary to recent suggestions, Mb deficiency significantly impairs and maximal running performance in mice. KEY POINTS: Myoglobin knockout mice (Mb ) possess lower maximal oxygen uptake ( ) and poorer maximal running performance than control mice (Mb ). Respiratory exchange ratio values at high running velocities in Mb mice are higher than in control mice suggesting a shift in substrate utilization towards glucose metabolism in Mb mice at the same running velocities. Lack of myoglobin lowers basal systemic and muscle NO bioavailability, but does not affect exercise-induced NO changes in plasma, heart and locomotory muscles. The present study demonstrates that myoglobin is of vital importance for and maximal running performance as well as explains why previous studies have failed to prove such a role of myoglobin when using the Mb mouse model.
Topics: Mice; Animals; Myoglobin; Nitrogen Dioxide; Running; Oxygen; Exercise Test; Mice, Knockout; Oxygen Consumption
PubMed: 38376957
DOI: 10.1113/JP285067 -
Food Chemistry Aug 2024(-)-Epigallocatechin-3-gallate (EGCG) is remarkably efficacious in inhibiting the browning of red meat. We therefore propose a hypothesis that EGCG forms complexes with...
(-)-Epigallocatechin-3-gallate (EGCG) is remarkably efficacious in inhibiting the browning of red meat. We therefore propose a hypothesis that EGCG forms complexes with myoglobin, thereby stabilizing its structure and thus preventing browning. This study investigated the interaction mechanism between EGCG and myoglobin. EGCG induced static quenching of myoglobin. Noncovalent forces, including hydrogen bonds and van der Waals, primarily governing the interactions between myoglobin and EGCG. The interactions primarily disrupted myoglobin's secondary structure, thus significantly reducing surface hydrophobicity by 53% (P < 0.05). The modification augmented the solubility and thermal stability of myoglobin. The radius of gyration (Rg) value fluctuated between 1.47 and 1.54 nm, and the hydroxyl groups in EGCG formed an average of 2.93 hydrogen bonds with myoglobin. Our findings elucidated the formation of stable myoglobin-EGCG complexes and the myoglobin-EGCG interaction, thus confirming our initial hypothesis.
Topics: Myoglobin; Catechin; Hydrophobic and Hydrophilic Interactions; Hydrogen Bonding; Animals; Protein Binding
PubMed: 38608400
DOI: 10.1016/j.foodchem.2024.139208 -
Meat Science Dec 2023In skeletal muscles, mitochondria have been shown to decrease the oxygen affinity of myoglobin. In this study, we investigated whether the mitochondrial function of...
In skeletal muscles, mitochondria have been shown to decrease the oxygen affinity of myoglobin. In this study, we investigated whether the mitochondrial function of decreasing myoglobin affinity for oxygen persists and operates at the final pH of postmortem bovine skeletal muscle. The oxygen affinity and myoglobin consumption in the presence of mitochondria obtained from fresh and wet-aged beef were evaluated and compared at pH 5.1, 5.6, and 5.7. The results showed that mitochondria obtained from fresh beef preserved myoglobin oxygen consumption and affinity interference, whereas those obtained from wet-aged beef did not. Oxygen consumption and affinity interference were mostly absent at pH 5.1 and were higher at pH 5.7 than those at pH 5.6. Our findings suggest that mitochondria contribute both to an increase in the oxygen affinity of myoglobin in aged meat and a decrease in the oxygen affinity of myoglobin in high-pH meat, such as dark-cutting beef.
PubMed: 37729860
DOI: 10.1016/j.meatsci.2023.109345 -
Journal of Inorganic Biochemistry Aug 2024Globins, such as myoglobin (Mb) and neuroglobin (Ngb), are ideal protein scaffolds for the design of functional metalloenzymes. To date, numerous approaches have been... (Review)
Review
Globins, such as myoglobin (Mb) and neuroglobin (Ngb), are ideal protein scaffolds for the design of functional metalloenzymes. To date, numerous approaches have been developed for enzyme design. This review presents a summary of the progress made in the design of functional metalloenzymes based on Mb and Ngb, with a focus on the exploitation of covalent interactions, including coordination bonds and covalent modifications. These include the construction of a metal-binding site, the incorporation of a non-native metal cofactor, the formation of Cys/Tyr-heme covalent links, and the design of disulfide bonds, as well as other Cys-covalent modifications. As exemplified by recent studies from our group and others, the designed metalloenzymes have potential applications in biocatalysis and bioconversions. Furthermore, we discuss the current trends in the design of functional metalloenzymes and highlight the importance of covalent interactions in the design of functional metalloenzymes.
Topics: Neuroglobin; Myoglobin; Globins; Nerve Tissue Proteins; Humans; Animals; Heme; Binding Sites; Metalloproteins; Protein Engineering
PubMed: 38759262
DOI: 10.1016/j.jinorgbio.2024.112595 -
Critical Reviews in Food Science and... 2024Color is an essential criterion for assessing the freshness, quality, and acceptability of red meat and certain fish with red muscle. Myoglobin (Mb), one of the... (Review)
Review
Color is an essential criterion for assessing the freshness, quality, and acceptability of red meat and certain fish with red muscle. Myoglobin (Mb), one of the significant pigment substances, is the uppermost reason to keep the color of red meat. Their oxidation and browning are easy to occur throughout the storage and processing period. Natural antioxidants are substances with antioxidant activity extracted from plants, such as plant polyphenols. Consumers prefer natural antioxidants due to safety concerns and limitations on the use of synthetic antioxidants. In recent years, plant polyphenols have been widely used as antioxidants to slow down the deterioration of product quality due to oxidation. As natural antioxidants, it is necessary to strengthen the researches on the antioxidant mechanism of plant polyphenols to solve the discoloration of red meat and certain fish. A fundamental review of the relationship between Mb oxidation and color stability is discussed. The inhibiting mechanisms of polyphenols on lipid and Mb oxidation are presented and investigated. Meanwhile, this review comprehensively outlines applications of plant polyphenols in improving color stability. This will provide reference and theoretical support for the rational application of plant polyphenols in green meat processing.
Topics: Animals; Myoglobin; Polyphenols; Oxidation-Reduction; Antioxidants; Meat; Red Meat; Plants; Plant Extracts; Color
PubMed: 36102134
DOI: 10.1080/10408398.2022.2122922