Search

Magnetic isotope and magnetic field effects on the rate of DNA synthesis catalysed by polymerases β with isotopic ions (24)Mg(2+), (25)Mg(2+) and (26)Mg(2+) in the catalytic sites were detected. No difference in enzymatic activity was found between polymerases β carrying (24)Mg(2+) and (26)Mg(2+) ions with spinless, non-magnetic nuclei (24)Mg and (26)Mg. However, (25)Mg(2+) ions with magnetic nucleus (25)Mg were shown to suppress enzymatic activity by two to three times with respect to the enzymatic activity of polymerases β with (24)Mg(2+) and (26)Mg(2+) ions. Such an isotopic dependence directly indicates that in the DNA synthesis magnetic mass-independent isotope effect functions. Similar effect is exhibited by polymerases β with Zn(2+) ions carrying magnetic (67)Zn and non-magnetic (64)Zn nuclei, respectively. A new, ion-radical mechanism of the DNA synthesis is suggested to explain these effects. Magnetic field dependence of the magnesium-catalysed DNA synthesis is in a perfect agreement with the proposed ion-radical mechanism. It is pointed out that the magnetic isotope and magnetic field effects may be used for medicinal purposes (trans-cranial magnetic treatment of cognitive deceases, cell proliferation, control of the cancer cells, etc).

The self‐assembly of small and always chiral molecules into fiber‐like structures is a mysterious process, as the physics underlying such self‐assembly is unclear. The energy necessary for this process exceeds the one provided by common dispersion interactions and hydrogen bonding. The recent results obtained by the scientific group of Prof. Naaman from the Weizmann Institute of Science fed light on the nature of forces providing for the self‐assembly of chiral molecules and attributed these forces to spin‐exchange interactions. Therefore, the self‐assembly of chiral molecules should be magneto‐sensitive. We found such sensitivity in solutions of trifluoroacetylated α‐amino alcohols, and the process was inhibited by the magnetic field when fibers grew on the surface of the substrate. On the contrary, in bulk, the self‐assembly was enhanced by the magnetic field and led to the formation of a dense gel, while no gelation was observed in the absence of the external magnetic field. The latter observations are the theme of this short report, aimed to declare the effect itself but not pretend to describe it in full. [ABSTRACT FROM AUTHOR]

The rate of a chemical reaction can be sensitive to the isotope composition of the reactants, which provides also for the sensitivity of such "spin-sensitive" reactions to the external magnetic field. Here we demonstrate the effect of the external magnetic field on the enzymatic DNA synthesis together with the effect of the spin-bearing magnesium ions ( 25 Mg). The rate of DNA synthesis monotonously decreased with the external magnetic field induction increasing in presence of zero-spin magnesium ions ( 24 Mg). On the contrary, in the presence of the spin-bearing magnesium ions, the dependence of the reaction rate on the magnetic field induction was non-monotonous and possess a distinct minimum at 80–100 mT. To describe the observed effect, we suggested a chemical scheme and biophysical mechanism considering a competition between Zeeman and Fermi interactions in the external magnetic field. [ABSTRACT FROM AUTHOR]

Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-022-26744-4, published online 10 January 2023 The original version of this Article contained an error in the spelling of the author Alexander S. Vedenkin which was incorrectly given as Alexander A. Vedenkin. The original article can be found online at https://doi.org/10.1038/s41598-022-26744-4. [Extracted from the article]

The article focuses on the impact of nuclear-magnetic isotopes on the enzymatic synthesis of adenosine triphosphate (ATP). It examines the catalytic activity of the 40 kDA active monomer, which is an electrophoretically crystallized homogeneous V. xanthia venom creatine kinase. Key information on the methodologies and results is presented.

Highlights: [•] Magnesium ions 25Mg2+ with magnetic nuclei 25Mg suppress enzymatic activity of polymerase β. [•] DNA synthesis depends on the magnetic field. [•] Polymerase chain reaction is also suppressed by 25Mg2+ ions. [•] Magnetic isotope and magnetic field effects may be used for medicinal purposes. [ABSTRACT FROM AUTHOR]

The increase of the domain shape dimensionality from one-dimensional (1D) to two-dimensional (2D) representing creation of the magnetic bubbles by application of the uniform magnetic field to the stripe domain structure is a well-known effect used for the magnetic memory. The analogy between ferromagnetic and ferroelectric domains stimulates a search of a similar effect in ferroelectrics. Here, we present the discovered 1D to 2D transformation of the domain shape under the action of pyroelectric field appeared in lithium niobate crystal as a result of irradiation by IR laser pulses. The imaging at the surface reveals the transformation of the stripe domains appeared after the first pulse into the regular arrays of isolated circular domains after the second pulse, whereas the imaging in the bulk reveals the transformation of the comb-like domain to array of isolated conical domains. The process was considered in terms of the kinetic approach. The mechanism of the comb-like domain formation by continuous tooth generation during domain elongation is proposed. The 1D to 2D transformation is attributed to the domain splitting due to the backward motion of the charged domain wall. The proposed mechanisms are confirmed by computer simulation of the temporal dependence of the pyroelectric field excess over the threshold value. [Display omitted] [ABSTRACT FROM AUTHOR]