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Manoj KM, Jacob VD, Kavdia M, Tamagawa H, Jaeken L, Soman V. Questioning rotary functionality in the bacterial flagellar system and proposing a murburn model for motility. J Biomol Struct Dyn 2023; 41:15691-15714. [PMID: 36970840 DOI: 10.1080/07391102.2023.2191146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 03/09/2023] [Indexed: 03/29/2023]
Abstract
Bacterial flagellar system (BFS) was the primary example of a purported 'rotary-motor' functionality in a natural assembly. This mandates the translation of a circular motion of components inside into a linear displacement of the cell body outside, which is supposedly orchestrated with the following features of the BFS: (i) A chemical/electrical differential generates proton motive force (pmf, including a trans-membrane potential, TMP), which is electro-mechanically transduced by inward movement of protons via BFS. (ii) Membrane-bound proteins of BFS serve as stators and the slender filament acts as an external propeller, culminating into a hook-rod that pierces the membrane to connect to a 'broader assembly of deterministically movable rotor'. We had disclaimed the purported pmf/TMP-based respiratory/photosynthetic physiology involving Complex V, which was also perceived as a 'rotary machine' earlier. We pointed out that the murburn redox logic was operative therein. We pursue the following similar perspectives in BFS-context: (i) Low probability for the evolutionary attainment of an ordered/synchronized teaming of about two dozen types of proteins (assembled across five-seven distinct phases) towards the singular agendum of rotary motility. (ii) Vital redox activity (not the gambit of pmf/TMP!) powers the molecular and macroscopic activities of cells, including flagella. (iii) Flagellar movement is noted even in ambiances lacking/countering the directionality mandates sought by pmf/TMP. (iv) Structural features of BFS lack component(s) capable of harnessing/achieving pmf/TMP and functional rotation. A viable murburn model for conversion of molecular/biochemical activity into macroscopic/mechanical outcomes is proposed herein for understanding BFS-assisted motility. HIGHLIGHTSThe motor-like functionalism of bacterial flagellar system (BFS) is analyzedProton/Ion-differential based powering of BFS is unviable in bacteriaUncouplers-sponsored effects were misinterpreted, resulting in a detour in BFS researchThese findings mandate new explanation for nano-bio-mechanical movements in BFSA minimalist murburn model for the bacterial flagella-aided movement is proposedCommunicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu, The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vivian David Jacob
- Satyamjayatu, The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Hirohisa Tamagawa
- Department of Mechanical Engineering, Gifu University, Gifu City, Japan
| | - Laurent Jaeken
- Department of Industrial Sciences and Technology, Karel de Grote-Hogeschool, Antwerp University Association, Belgium
| | - Vidhu Soman
- Department of Bioscience & Bioengineering, IIT Bombay (& DSS Imagetech Pvt. Ltd), Mumbai, Maharashtra, India
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Manoj KM, Soman V, David Jacob V, Parashar A, Gideon DA, Kumar M, Manekkathodi A, Ramasamy S, Pakshirajan K, Bazhin NM. Chemiosmotic and murburn explanations for aerobic respiration: Predictive capabilities, structure-function correlations and chemico-physical logic. Arch Biochem Biophys 2019; 676:108128. [PMID: 31622585 DOI: 10.1016/j.abb.2019.108128] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 12/18/2022]
Abstract
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.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India.
| | - Vidhu Soman
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Vivian David Jacob
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research, Vadlamudi, Guntur, 522213, India
| | - Daniel Andrew Gideon
- Department of Biotechnology & Bioinformatics, Bishop Heber College (Autonomous), Tennur, Tiruchirappalli, 620017, India
| | - Manish Kumar
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India
| | - Afsal Manekkathodi
- Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Al-Rayyan PO Box 34110, Qatar
| | - Surjith Ramasamy
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Kannan Pakshirajan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Nikolai Mikhailovich Bazhin
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, St. Institutskaya 3, 630090, Novosibirsk, Russia.
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Musielak M, Piotrowski I, Suchorska WM. Superparamagnetic iron oxide nanoparticles (SPIONs) as a multifunctional tool in various cancer therapies. Rep Pract Oncol Radiother 2019; 24:307-314. [PMID: 31193459 DOI: 10.1016/j.rpor.2019.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/25/2019] [Accepted: 04/20/2019] [Indexed: 12/19/2022] Open
Abstract
Over the past two decades nanotechnology has become an important part of novel medical research. Researchers have made great progress in developing nanotechnology applications used for detecting and treating oncological diseases. Recently, many research groups have focused on the use of superparamagnetic iron oxide nanoparticles (SPIONs) in cancer treatment. Due to the range of therapeutic properties and possibilities of various modifications, SPIONs are a promising and multifunctional tool in various cancer therapies and may help to overcome the limitations of conventional therapies. Moreover, it is still necessary to develop new methods of treatment with expected properties, such as lower toxicity, long-lasting effectiveness and higher selectivity. Analyzing the literature data, we found that currently SPIONs are used in the transport of drugs, immunotherapy and hyperthermia. The main aim of this review is to present various cancer treatment therapies utilizing SPIONs, the importance of the experiments carried out by research groups and further perspectives in the nanotechnological use of SPIONs.
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Affiliation(s)
- Marika Musielak
- Radiobiology Laboratory, Greater Poland Cancer Centre, 61-866 Poznań, Poland
| | - Igor Piotrowski
- Radiobiology Laboratory, Greater Poland Cancer Centre, 61-866 Poznań, Poland.,Department of Electroradiology, Poznań University of Medical Sciences, 61-701 Poznań, Poland
| | - Wiktoria M Suchorska
- Radiobiology Laboratory, Greater Poland Cancer Centre, 61-866 Poznań, Poland.,Department of Electroradiology, Poznań University of Medical Sciences, 61-701 Poznań, Poland
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Manoj KM, Parashar A, David Jacob V, Ramasamy S. Aerobic respiration: proof of concept for the oxygen-centric murburn perspective. J Biomol Struct Dyn 2019; 37:4542-4556. [PMID: 30488771 DOI: 10.1080/07391102.2018.1552896] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The inner mitochondrial membrane protein complexes (I-V) and prokaryotic respiratory machinery are examined for a deeper understanding of their structure-function correlations and dynamics. In silico analysis of the structure of complexes I-IV, docking studies and erstwhile literature confirm that they carry sites which are in close proximity to DROS (diffusible reactive oxygen species) generating redox centers. These findings provide supportive evidence for the newly proposed oxygen-centric chemical-coupling mechanism (murburn concept), wherein DROS catalyzes the esterification of inorganic phosphate to ADP. Further, in a reductionist system, we demonstrate that a DROS (like superoxide) can effectively esterify inorganic phosphate to ADP. The impact of these findings and the interactive dynamics of classical inhibitors (rotenone and cyanide), uncouplers (dinitrophenol and uncoupling protein) and other toxins (atractyloside and oligomycin) are briefly discussed. Highlights • Earlier perception: Complexes (I-IV) pump protons and Complex V make ATP (aided by protons) • Herein: Respiratory molecular machinery is probed for new structure-function correlations • Analyses: Quantitative arguments discount proton-centric ATP synthesis in mitochondria and bacteria • In silico data: ADP-binding sites and O2/ diffusible reactive oxygen species (DROS)-accessible channels are unveiled in respiratory proteins • In vitro data: Using luminometry, ATP synthesis is demonstrated from ADP, Pi and superoxide • Inference: Findings agree with decentralized ADP-Pi activation via oxygen-centric murburn scheme Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research , Vadlamudi , Guntur, Andhra Pradesh, India
| | | | - Surjith Ramasamy
- Department of Biotechnology, Indian Institute of Technology Guwahati , Guwahati , Assam, India
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Manoj KM. Aerobic Respiration: Criticism of the Proton-centric Explanation Involving Rotary Adenosine Triphosphate Synthesis, Chemiosmosis Principle, Proton Pumps and Electron Transport Chain. BIOCHEMISTRY INSIGHTS 2018; 11:1178626418818442. [PMID: 30643418 PMCID: PMC6311555 DOI: 10.1177/1178626418818442] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 11/20/2018] [Indexed: 12/17/2022]
Abstract
The acclaimed explanation for mitochondrial oxidative phosphorylation (mOxPhos, or cellular respiration) is a deterministic proton-centric scheme involving four components: Rotary adenosine triphosphate (ATP)-synthesis, Chemiosmosis principle, Proton pumps, and Electron transport chain (abbreviated as RCPE hypothesis). Within this write-up, the RCPE scheme is critically analyzed with respect to mitochondrial architecture, proteins’ distribution, structure-function correlations and their interactive dynamics, overall reaction chemistry, kinetics, thermodynamics, evolutionary logic, and so on. It is found that the RCPE proposal fails to explain key physiological aspects of mOxPhos in several specific issues and also in holistic perspectives. Therefore, it is imperative to look for new explanations for mOxPhos.
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Abstract
According to the chemosmotic hypothesis, ATP is synthesized in mitochondria, bacteria and chloroplasts via the proton motive force delta p, the energy-rich intermediate of electron transport and photosynthetic phosphorylation. The general applicability of the chemosmotic hypothesis, however, was disputed until present. In particular the relationship between the rate of respiration and delta p in mitochondria was found variable, depending on the experimental conditions. Recently, a new mechanism of respiratory control was found, based on binding of ATP or ADP to subunit IV of cytochrome c oxidase, which is independent of delta p and could explain many previous results contradicting the chemosmotic hypothesis.
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Affiliation(s)
- B Kadenbach
- Fachbereich Chemie, Philipps-Universität, Marburg, Germany.
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Mărgineanu DG. Equilibrium and non-equilibrium approaches in biomembrane thermodynamics. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1987; 95:381-422. [PMID: 2452614 DOI: 10.3109/13813458709075033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- D G Mărgineanu
- Laboratory of Biophysics, Faculty of Biology, University of Bucharest, Romania
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