Thermal Denaturation and Aggregation of Myosin Subfragment 1 Isoforms with Different Essential Light Chains

Markov, Denis I.; Zubov, Eugene O.; Nikolaeva, Olga; Bi, Kurganov; Levitsky, Dmitrii I.

doi:10.3390/ijms11114194

Cited by 20 publications

(31 citation statements)

References 38 publications

(42 reference statements)

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“…It seems quite possible that the environment of these residues becomes more hydrophobic as a result of aggregation of the protein, which accompanies its thermal denaturation. A very similar effect (blue-shift of the Trp fluorescence spectrum) was previously observed for myosin subfragment 1, whose thermal denaturation was also accompanied by spontaneous aggregation (Markov et al 2010). Interestingly, among four α-amylase isoforms, only one demonstrated the blue-shift upon thermal denaturation, in contrast to all other protein species, which demonstrated the usual red-shift (Duy and Fitter 2006).…”

Section: Discussionsupporting

confidence: 67%

“…5). A similar so-called blue-shift of the spectrum was previously described for myosin subfragment 1 after its thermal denaturation accompanied by aggregation (Markov et al 2010). This spectral shift means that the environment of Trp residues becomes more hydrophobic after denaturation and aggregation of the protein.…”

Section: Temperature-induced Changes In the Intrinsic Fluorescence Ofmentioning

confidence: 81%

“…The blue-shift of the spectrum was accompanied by an increase in the parameter A (320/365 nm, Fig. 6) (Markov et al 2010). The temperature dependence of this parameter showed the main transition with a mid-point at about 81.9 °C (Fig.…”

Section: Temperature-induced Changes In the Intrinsic Fluorescence Ofmentioning

confidence: 97%

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Heat-induced conformational changes of TET peptidase from crenarchaeon Desulfurococcus kamchatkensis

et al. 2015

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The effects of heating on the structure and stability of multimeric TET aminopeptidase (APDkam589) were studied by differential scanning calorimetry, tryptophan fluorescence quenching, and dynamic light scattering. Thermally induced structural changes in APDkam589 were found to occur in two phases: local conformational changes, which occur below 70 °C and are not associated with thermal denaturation of the protein, and global structural changes (above 70 °C) induced by irreversible thermal unfolding of the protein accompanied by its spontaneous aggregation. These results may explain the bell-shaped temperature dependence with a maximum at ~70 °C previously observed for enzymatic activity of APDkam589. Interestingly, the thermal unfolding of APDkam589 at about 81.2 °C is accompanied by a so-called blue-shift of about 10 nm-a shift of the Trp fluorescence spectrum toward shorter wavelength. From this point of view, APDkam589 is quite different from most proteins, which are characterized by a long wavelength shift of the spectrum ("red-shift") upon denaturation. The blue-shift of the Trp fluorescence spectrum reflects the changes in the environment of Trp residues, which becomes more hydrophobic upon denaturation. The molecular structure of APDkam589 was determined by X-ray diffraction. The monomer of APDkam589 has six Trp residues, five of which are on the external surface of the dodecamer. Therefore, the blue-shift of the Trp fluorescence spectrum can be explained, at least partly, by aggregation of APDkam589, which occurs simultaneously with its thermal denaturation and probably makes the environment of these Trp residues more hydrophobic.

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Section: Discussionsupporting

confidence: 67%

Section: Temperature-induced Changes In the Intrinsic Fluorescence Ofmentioning

confidence: 81%

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Heat-induced conformational changes of TET peptidase from crenarchaeon Desulfurococcus kamchatkensis

et al. 2015

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“…The thermogram of untreated myofibrillar proteins showed at least 3 overlapping peaks at 42, 48, and 54°C (Figure ), which corresponded to myosin domains (42 and 48°C) and actomyosin (54°C) (Findlay and others ; Markov and other ). The thermal unfolding of myofibrillar proteins was affected by the increased pressure level, as observed by the width and the shape of transitions.…”

Section: Resultsmentioning

confidence: 94%

Influence of Xanthan Gum on the Structural Characteristics of Myofibrillar Proteins Treated by High Pressure

Villamonte

Jury

Jung

et al. 2015

Journal of Food Science

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The effects of xanthan gum on the structural modifications of myofibrillar proteins (0.3 M NaCl, pH 6) induced by high pressure (200, 400, and 600 MPa, 6 min) were investigated. The changes in the secondary and tertiary structures of myofibrillar proteins were analyzed by circular dichroism. The protein denaturation was also evaluated by differential scanning calorimetry. Likewise, the protein surface hydrophobicity and the solubility of myofibrillar proteins were measured. High pressure (600 MPa) induced the loss of α-helix structures and an increase of β-sheet structures. However, the presence of xanthan gum hindered the former mechanism of protein denaturation by high pressure. In fact, changes in the secondary (600 MPa) and the tertiary structure fingerprint of high-pressure-treated myofibrillar proteins (400 to 600 MPa) were observed in the presence of xanthan gum. These modifications were confirmed by the thermal analysis, the thermal transitions of high-pressure (400 to 600 MPa)-treated myofibrillar proteins were modified in systems containing xanthan gum. As consequence, the high-pressure-treated myofibrillar proteins with xanthan gum showed increased solubility from 400 MPa, in contrast to high-pressure treatment (600 MPa) without xanthan gum. Moreover, the surface hydrophobicity of high-pressure-treated myofibrillar proteins was enhanced in the presence of xanthan gum. These effects could be due to the unfolding of myofibrillar proteins at high-pressure levels, which exposed sites that most likely interacted with the anionic polysaccharide. This study suggests that the role of food additives could be considered for the development of meat products produced by high-pressure processing.

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“…To disclose such domains in the myosin head, in early works, made more than 20 years ago, the so-called “successive annealing” method was applied in DSC studies on the thermal unfolding of skeletal S1, which revealed three separate transitions (calorimetric domains) in the S1 molecule [ 18 , 22 , 26 , 27 ]. More recently, a new calorimetric approach was specifically developed to analyze the DSC profiles of irreversibly denaturing multidomain proteins, and this approach was applied for detailed analysis of the domain structure of nucleotide-free S1 [ 28 ]. Using this approach, we revealed two calorimetric domains in the S1 molecule, where the more thermostable domain denatured in two steps.…”

Section: Introductionmentioning

confidence: 99%

Does Interaction between the Motor and Regulatory Domains of the Myosin Head Occur during ATPase Cycle? Evidence from Thermal Unfolding Studies on Myosin Subfragment 1

et al. 2015

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Myosin head (myosin subfragment 1, S1) consists of two major structural domains, the motor (or catalytic) domain and the regulatory domain. Functioning of the myosin head as a molecular motor is believed to involve a rotation of the regulatory domain (lever arm) relative to the motor domain during the ATPase cycle. According to predictions, this rotation can be accompanied by an interaction between the motor domain and the C-terminus of the essential light chain (ELC) associated with the regulatory domain. To check this assumption, we applied differential scanning calorimetry (DSC) combined with temperature dependences of fluorescence to study changes in thermal unfolding and the domain structure of S1, which occur upon formation of the ternary complexes S1-ADP-AlF4 - and S1-ADP-BeFx that mimic S1 ATPase intermediate states S1**-ADP-Pi and S1*-ATP, respectively. To identify the thermal transitions on the DSC profiles (i.e. to assign them to the structural domains of S1), we compared the DSC data with temperature-induced changes in fluorescence of either tryptophan residues, located only in the motor domain, or recombinant ELC mutants (light chain 1 isoform), which were first fluorescently labeled at different positions in their C-terminal half and then introduced into the S1 regulatory domain. We show that formation of the ternary complexes S1-ADP-AlF4 - and S1-ADP-BeFx significantly stabilizes not only the motor domain, but also the regulatory domain of the S1 molecule implying interdomain interaction via ELC. This is consistent with the previously proposed concepts and also adds some new interesting details to the molecular mechanism of the myosin ATPase cycle.

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Thermal Denaturation and Aggregation of Myosin Subfragment 1 Isoforms with Different Essential Light Chains

Cited by 20 publications

References 38 publications

Heat-induced conformational changes of TET peptidase from crenarchaeon Desulfurococcus kamchatkensis

Heat-induced conformational changes of TET peptidase from crenarchaeon Desulfurococcus kamchatkensis

Influence of Xanthan Gum on the Structural Characteristics of Myofibrillar Proteins Treated by High Pressure

Does Interaction between the Motor and Regulatory Domains of the Myosin Head Occur during ATPase Cycle? Evidence from Thermal Unfolding Studies on Myosin Subfragment 1

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