Publications by authors named "Nikolai Bazhin"

9 Publications

  • Page 1 of 1

The murburn precepts for cellular ionic homeostasis and electrophysiology.

J Cell Physiol 2021 Aug 11. Epub 2021 Aug 11.

Department of Mechanical Engineering, Gifu University, Yanagido, Gifu, Japan.

Starting from the basic molecular structure and redox properties of its components, we build a macroscopic cellular electrophysiological model. We first present a murburn purview that could explain ion distribution in bulk-milieu/membrane-interface and support the origin of trans-membrane potential (TMP) in cells. In particular, the discussion focuses on how cells achieve disparity in the distribution of monovalent and divalent cations within (K  > Na  > Mg  > Ca ) and outside (Na  > K  > Ca  > Mg ). We explore how TMP could vary for resting/graded/action potentials generation and project a model for impulse conduction in neurons. Outcomes based on murburn bioenergetic equilibriums leading to solubilization of ion-pairs, membrane's permittivity, protein channels' fluxes, and proteins' innate ability to bind/adsorb ions selectively are projected as the integral rationale. We also provide experimental modalities to ratify the projections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcp.30547DOI Listing
August 2021

Structure-function correlations and system dynamics in oxygenic photosynthesis: classical perspectives and murburn precepts.

J Biomol Struct Dyn 2021 Jul 29:1-27. Epub 2021 Jul 29.

Satyamjayatu: The Science & Ethics Foundation, Kulappully, Kerala, India.

Highlights: Contemporary beliefs on oxygenic photosynthesis are critiqued.Murburn model is suggested as an alternative explanation.In the new model, diffusible reactive species are the main protagonists.All pigments are deemed photo-redox active in the new stochastic mechanism.NADPH synthesis occurs via simple electron transfers, not via elaborate ETC.Oxygenesis is delocalized and not just centered at Mn-Complex.Energetics of murburn proposal for photophosphorylation is provided.The proposal ushers in a paradigm shift in photosynthesis research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07391102.2021.1953606DOI Listing
July 2021

Chemiosmotic and murburn explanations for aerobic respiration: Predictive capabilities, structure-function correlations and chemico-physical logic.

Arch Biochem Biophys 2019 11 14;676:108128. Epub 2019 Oct 14.

Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, St. Institutskaya 3, 630090, Novosibirsk, Russia. Electronic address:

Since mid-1970s, the proton-centric proposal of 'chemiosmosis' became the acclaimed explanation for aerobic respiration. Recently, significant theoretical and experimental evidence were presented for an oxygen-centric 'murburn' mechanism of mitochondrial ATP-synthesis. Herein, we compare the predictive capabilities of the two models with respect to the available information on mitochondrial reaction chemistry and the membrane proteins' structure-function correlations. Next, fundamental queries are addressed on thermodynamics of mitochondrial oxidative phosphorylation (mOxPhos): (1) Can the energy of oxygen reduction be utilized for proton transport? (2) Is the trans-membrane proton differential harness-able as a potential energy capable of doing useful work? and (3) Whether the movement of miniscule amounts of mitochondrial protons could give rise to a potential of ~200 mV and if such an electrical energy could sponsor ATP-synthesis. Further, we explore critically if rotary ATPsynthase activity of Complex V can account for physiological ATP-turnovers. We also answer the question- "What is the role of protons in the oxygen-centric murburn scheme of aerobic respiration?" Finally, it is demonstrated that the murburn reaction model explains the fast kinetics, non-integral stoichiometry and high yield of mOxPhos. Strategies are charted to further demarcate the two explanations' relevance in the cellular physiology of aerobic respiration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.abb.2019.108128DOI Listing
November 2019

[Fe(Ox)] complex as a photodegradation agent at neutral pH: Advances and limitations.

Chemosphere 2018 Mar 16;195:839-846. Epub 2017 Dec 16.

V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation; Novosibirsk State University, 2 Pirogova St., 630090, Novosibirsk, Russian Federation.

In the present work advances and limitations in the application of Fe(III)-oxalate complexes (namely, [Fe(Ox)]) to the photodegradation of a model persistent organic contaminant - 2,4-dichlorophenoxybutanoic acid (2,4-DB) in neutral aqueous solutions were systematically investigated for the first time. It has been shown that the efficiency of [Fe(Ox)] system greatly depends on the initial concentrations of oxalate ion due to the fast consumption of the ligand during photodegradation process leading to the formation of photochemically less active Fe(III) species. Efficiency of Fe(Ox) system normalized to UVA absorption at the excitation wavelength is practically independent on [Fe(III)]. Thus, it is highly probable that concentrations of Fe(III) as low as < 10 M could be applied in water treatment procedures using reactors with very long optical path. The system also keeps high efficiency at low concentration of pollutant (<10 M) though this results in higher relative consumption rate of Fe(III) and oxalate ions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chemosphere.2017.12.096DOI Listing
March 2018

Photooxidation of herbicide amitrole in the presence of fulvic acid.

Environ Sci Pollut Res Int 2018 Jul 23;25(21):20320-20327. Epub 2017 Feb 23.

V.V. Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya str, Novosibirsk, Russian Federation, 630090.

Fulvic acid (Henan ChangSheng Corporation) photoinduced degradation of non-UVA-absorbing herbicide amitrole (3-amino-1,2,4-triazole, AMT) as a way for its removal from polluted water was investigated in details. It was shown that the main primary species generated by fulvic acid under UVA radiation, triplet state and hydrated electron, are not directly involved in the herbicide degradation. AMT decays in reactions with secondary intermediates, reactive oxygen species, formed in reactions of the primary ones with dissolved oxygen. Singlet oxygen is responsible for 80% of herbicide oxidation, and OH and O radicals-for the remaining 20% of AMT. It was found that quantum yield of AMT photodegradation (ϕ ) decreases linearly from 2.2 × 10 to 1.2 × 10 with the increase of fulvic acid concentration from 1.1 to 30 mg L. On the contrary, the increase of AMT concentration from 0.8 to 25 mg L leads to practically linear growth of ϕ value from 1.8 × 10 to 4 × 10. Thus, the fulvic acid exhibits a good potential as UVA photooxidizer of organic pollutants sensitive to the singlet oxygen (ϕ (O) = 0.025 at pH 6.5).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-017-8580-xDOI Listing
July 2018

Laser flash photolysis study of photocatalytic properties of pillared interlayered clays and Fe,Al-silica mesoporous catalysts.

Photochem Photobiol Sci 2013 Nov;12(11):1939-47

Voevodsky Institute of Chemical Kinetics and Combustion, 3 Institutskaya Str., 630090, Novosibirsk, Russian Federation.

Laser flash photolysis was applied to determine the primary photochemical processes over iron-containing clay (montmorillonite KSF), pillared interlayered clays (PILCs) and mesoporous mesophase iron silicate materials (MMMs). For KSF, the homogeneous photochemical reaction of Fe(III) leached from the clay material resulted in the formation of OH radicals, which were monitored by means of their reaction with methyl viologen dication (MV(2+)). For PILCs and MMMs, no leaching of Fe(III) to the solution nor hydroxyl radical formation were observed. Nevertheless, these catalysts were found to exhibit a sufficient effect on phenol photoionization. The increase in quantum yields of PhO radicals is caused by the effect of PILCs and MMMs and is explained by heterogeneous processes on the surface of catalyst particles.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c3pp50112dDOI Listing
November 2013

The essence of ATP coupling.

Authors:
Nikolai Bazhin

ISRN Biochem 2012 9;2012:827604. Epub 2012 May 9.

Institute of Chemical Kinetics and Combustion, Novosibirsk State University, Institutskaya 3, Novosibirsk 630090, Russia.

The traditional explanation of ATP coupling is based on the raising of the equilibrium constants of the biochemical reactions. But in the frames of the detailed balance, no coupling occurs under thermodynamic equilibrium. The role of ATP in coupling is not that it provides an increase in the equilibrium constants of thermodynamically unfavorable reactions but that the unfavorable reactions are replaced by other reactions which kinetically are more favorable and give rise to the same products. The coupling with ATP hydrolysis results in the formation of quasistationary intermediate states.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5402/2012/827604DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4393006PMC
May 2015

New insight into photochemistry of ferrioxalate.

J Phys Chem A 2008 Sep 15;112(36):8316-22. Epub 2008 Aug 15.

Institute of Chemical Kinetics and Combustion, Institutskaya 3, and Novosibirsk State University, Pirogova 2, 630090 Novosibirsk, Russia.

Optical spectroscopy and nanosecond flash photolysis (Nd:YAG laser, 355 nm, pulse duration 5 ns, mean energy 5 mJ/pulse) were used to study the photochemistry of Fe(III)(C2O4)3(3-) complex in aqueous solutions. The main photochemical process was found to be intramolecular electron transfer from the ligand to Fe(III) ion with formation of a primary radical complex [(C2O4)2Fe(II)(C2O4(*))](3-). The yield of radical species (i.e., CO2(*-) and C2O4(*-)) was found to be less than 6% of Fe(III)(C2O4)3(3-) disappeared after flash. [(C2O4)2Fe(II)(C2O4(*))](3-) dissociates reversibly into oxalate ion and a secondary radical complex, [(C2O4)Fe(II)(C2O4(*))](-). The latter reacts with the initial complex and dissociates to Fe(II)(C2O4) and oxalate radical. In this framework, the absorption spectra and rate constants of the reactions of all intermediates were determined.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jp8040583DOI Listing
September 2008

Photodegradation of glyphosate in the ferrioxalate system.

J Hazard Mater 2007 Sep 23;148(1-2):360-5. Epub 2007 Feb 23.

School of Resources and Environmental Science, Wuhan University, Wuhan 430079, PR China.

The photoinduced degradation of glyphosate (GLP) in the ferrioxalate system was investigated under irradiation with a 250W metal halide lamp (lambda>/=365nm). The efficiency of orthophosphates release, representing the photodegradation efficiency of GLP, increased with decreasing the initial concentrations of GLP and Fe(III)/oxalate ratios. At acidic pH value in the range of 3.5-5.0, higher efficiency of orthophosphates release up to 60.6% was achieved, while the efficiency dropped to 42.1% at pH 6.0. The photochemical process mainly involved the predominant species of iron(III), namely Fe(C(2)O(4))(2)(-) and Fe(C(2)O(4))(3)(3-), which lead to the formation of hydroxyl radicals in the presence of dissolved oxygen under UV-vis irradiation. Also, the complexation of GLP with Fe(III) obviously increased the light absorption of GLP and facilitated its degradation by direct photolysis. The ninhydrin test for primary amines showed that the GLP was attacked by hydroxyl radicals with CN cleavage to yield aminomethylphosphonic acid (AMPA) and CP cleavage to yield sarcosine. The photodegradation may be enhanced by the decomposition of reactive radicals produced through ligand-to-metal charge transfer (LMCT) of ferric-GLP complexes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jhazmat.2007.02.044DOI Listing
September 2007
-->