scholarly journals Heat-Dependent Hairpin Melting Drives TRPV1 Opening

2022 ◽  
Author(s):  
Guangyu Wang
Keyword(s):  
Structural Model ◽  
High Heat ◽  
Structural Basis ◽  
Heat Denaturation ◽  
Temperature Threshold ◽  
Heat Sensitivity ◽  
Noxious Heat ◽  
Outer Pore ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The capsaicin receptor TRPV1 can be activated by heat and thus serves as a thermometer in a primary afferent sensory neuron for noxious heat detection. However, the underlying molecular mechanism is unclear. Here, a hairpin topological structural model, together with graph theory, was developed to examine a role of temperature-dependent hairpin melting in controlling non-covalent interactions along the heat-evoked gating pathway of TRPV1. The results showed that heat-dependent hairpin melting rearranges non-covalent interactions, releases the resident lipid, and induces TRPV1 gating. A larger hairpin in the outer pore initiates a temperature threshold as a heat starter for channel opening while some smaller hairpins in the S4-S5 linker and the outer pore stabilize the heat efficacy and avoid heat denaturation as a heat fuse. The heat-induced global gating rearrangement may be responsible for the high heat sensitivity. This hairpin model may provide a broad structural basis for the thermo-gated ion channels.

scholarly journals Structural basis of peroxidase catalytic cycle of human Prdx6

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rimpy Kaur Chowhan ◽  
Hamidur Rahaman ◽  
Laishram Rajendrakumar Singh
Keyword(s):  
Redox State ◽  
Redox Status ◽  
Structural Basis ◽  
Peroxiredoxin 6 ◽  
Solution Structures ◽  
The Family ◽  
Non Covalent Interactions ◽  
The Impact ◽  
Prosthetic Groups ◽  
Covalent Interactions

Abstract Peroxiredoxin 6 (Prdx6) is a ubiquitously expressed antioxidant non-selenium glutathione peroxidase that is known to play a major role in various physiological and pathological processes. It belongs to the family of peroxidases (referred to as Peroxiredoxins, Prdx’s) that work independently of any prosthetic groups or co-factors, and instead utilize a peroxidatic thiol residue for peroxide reduction. Mammalian Prdx’s are classified according to the number of Cys implicated in their catalytic activity by the formation of either inter-molecular (typical 2-Cys, Prdx1–4) or intra-molecular (atypical 2-Cys, Prdx5) disulfide bond, or non-covalent interactions (1-Cys, Prdx6). The typical and atypical 2-Prdx’s have been identified to show decamer/dimer and monomer/dimer transition, respectively, upon oxidation of their peroxidatic cysteine. However, the alterations in the oligomeric status of Prdx6 as a function of peroxidatic thiol’s redox state are still ambiguous. While the crystal structure of recombinant human Prdx6 is resolved as a dimer, the solution structures are reported to have both monomers and dimers. In the present study, we have employed several spectroscopic and electrophoretic probes to discern the impact of change in the redox status of peroxidatic cysteine on conformation and oligomeric status of Prdx6. Our study indicates Prdx6′s peroxidase activity to be a redox-based conformation driven process which essentially involves monomer–dimer transition.

scholarly journals Design Maps of TRPM8 as a Thermometer for Cold Detection

2022 ◽  
Author(s):  
Guangyu Wang
Keyword(s):  
Low Temperature ◽  
Design Principle ◽  
Structural Model ◽  
Trp Channels ◽  
Structural Basis ◽  
Cold Sensitivity ◽  
Temperature Threshold ◽  
Pore Domain ◽  
Hairpin Formation

The menthol sensor TRPM8 can be activated by cold and thus serves as a thermometer in a primary afferent sensory neuron for noxious cold detection. However, the underlying design principle is unknown. Here, a hairpin topological structural model and graph theory were prepared to test a role of the cold-dependent hairpin formation in the cold-evoked gating pathway of TRPM8. The results showed that the formation of a large lipid-dependent hairpin initiates a low temperature threshold in favor of TRPM8 activation. Furthermore, two smaller hairpins, which enhance the coupled interactions of the voltage-sensor-like domain with both the pore domain and the TRP domain, can stabilize the cold efficacy and work as a fuse to prevent cold denaturation. The cold-induced hairpin rearrangements along the gating pathway may be necessary for the high cold sensitivity. This hairpin model may provide a structural basis for activation of the thermo-gated TRP channels at low temperature.

Effects of Non-covalent Interactions with 5-O-Caffeoylquinic Acid (Chlorogenic Acid) on the Heat Denaturation and Solubility of Globular Proteins

2003 ◽  
Vol 51 (17) ◽  
pp. 5088-5095 ◽  
Author(s):  
Stéphanie V. E. Prigent ◽  
Harry Gruppen ◽  
Antonie J. W. G. Visser ◽  
Gerrit A. van Koningsveld ◽  
Govardus A. H. de Jong ◽  
...  
Keyword(s):  
Chlorogenic Acid ◽  
Globular Proteins ◽  
Heat Denaturation ◽  
Caffeoylquinic Acid ◽  
Non Covalent Interactions ◽  
Covalent Interactions

NON COVALENT INTERACTIONS IN LARGE DIAMONDOID DIMERS IN THE GAS PHASE - A MICROWAVE STUDY

2017 ◽  
Author(s):  
Cristobal Perez ◽  
Melanie Schnell ◽  
Peter Schreiner ◽  
Norbert Mitzel ◽  
Yury Vishnevskiy ◽  
...  
Keyword(s):  
Gas Phase ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Vapour Pressure Isotope Effect on Evaporation from Pure Organic Phases - a PIMD Approach

2020 ◽  
Author(s):  
Luis Vasquez ◽  
Agnieszka Dybala-Defratyka
Keyword(s):  
Path Integral ◽  
Vapour Pressure ◽  
Density Functional ◽  
Isotope Effects ◽  
Tight Binding ◽  
Decomposition Analysis ◽  
Energy Decomposition Analysis ◽  
Special Importance ◽  
Non Covalent Interactions ◽  
Covalent Interactions

<p></p><p>Very often in order to understand physical and chemical processes taking place among several phases fractionation of naturally abundant isotopes is monitored. Its measurement can be accompanied by theoretical determination to provide a more insightful interpretation of observed phenomena. Predictions are challenging due to the complexity of the effects involved in fractionation such as solvent effects and non-covalent interactions governing the behavior of the system which results in the necessity of using large models of those systems. This is sometimes a bottleneck and limits the theoretical description to only a few methods.<br> In this work vapour pressure isotope effects on evaporation from various organic solvents (ethanol, bromobenzene, dibromomethane, and trichloromethane) in the pure phase are estimated by combining force field or self-consistent charge density-functional tight-binding (SCC-DFTB) atomistic simulations with path integral principle. Furthermore, the recently developed Suzuki-Chin path integral is tested. In general, isotope effects are predicted qualitatively for most of the cases, however, the distinction between position-specific isotope effects observed for ethanol was only reproduced by SCC-DFTB, which indicates the importance of using non-harmonic bond approximations.<br> Energy decomposition analysis performed using the symmetry-adapted perturbation theory (SAPT) revealed sometimes quite substantial differences in interaction energy depending on whether the studied system was treated classically or quantum mechanically. Those observed differences might be the source of different magnitudes of isotope effects predicted using these two different levels of theory which is of special importance for the systems governed by non-covalent interactions.</p><br><p></p>

scholarly journals Heterogenisation of polyoxometalates and other metal-based complexes in metal–organic frameworks: from synthesis to characterisation and applications in catalysis

2021 ◽  
Author(s):  
P. Mialane ◽  
C. Mellot-Draznieks ◽  
P. Gairola ◽  
M. Duguet ◽  
Y. Benseghir ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Coordination Complexes ◽  
Metal Organic ◽  
Non Covalent Interactions ◽  
Molecular Catalysts ◽  
Covalent Interactions

This review provides a thorough overview of composites with molecular catalysts (polyoxometalates, or organometallic or coordination complexes) immobilised into MOFs via non-covalent interactions.

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