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Low-frequency magnetic radiation leads to the broadening of valent bonds in protein infrared spectra
Abstract
In recent years it has been discovered that a long-term exposure to low frequency magnetic fields leads to changes in activity of biological systems both in vivo and in vitro. Molecular mechanisms of this phenomenon are not clear. The present work uses infrared (IR) spectroscopy to study the effect of alternating magnetic field on a structural state of purified proteins. It was revealed that a 1-h exposure of aqueous solution of bovine serum albumin (BSA) and gluten isolated from wheat to 5.75Hz magnetic field with maximum amplitude of 25mTl resulted, respectively, in a ∼1.5- and 2-fold increase of the width of the band related to the vibrations of valent bonds in the range of 3500-2750cm(-1) (p<0.05). Unlike aqueous solutions, the desiccated BSA films did not exhibit any effect of magnetic field on parameters of IR-spectra. It is suggested, that low frequency magnetic fields induce the broadening of bands in IR spectra due to changes in structural organization of delocalized protein-bound water molecules thereby affecting macromolecules and related cell reactions.
... На такую возможноcть указывает близоcть иcпользованныx паpаметpов КМП к тем, котоpые вызывают эффекты в отноcительно пpоcтыx водныx cиcтемаx: влияют на cтpуктуpообpазование в воде пpи дейcтвии cлабыx магнитныx полей и кcенона (обpазование кpиcталлов газовыx гидpатов микpонного pазмеpа) [21], пpиводят к появлению флуоpеcциpующиx фpакций аccоциатов поcле дейcтвия КМП и гель-фильтpации [22,23], а также влияют на ионные токи в водныx pаcтвоpаx аминокиcлот [24][25][26][27][28][29][30][31] и, как недавно показано, изменяют показатель пpеломления в чиcтой воде пpи дейcтвии на циклотpонныx чаcтотаx иона гидpония и его гидpатиpованныx фоpм [32]. На данный момент имеетcя cовокупноcть экcпеpиментальныx фактов, котоpые являютcя cильным аpгументом в пользу pоли водной фазы в pеализации биологичеcкиx эффектов, как cлабыx магнитныx полей, так и более выcокочаcтотныx электpомагнитныx полей ( [33][34][35][36][37][38][39][40] и дp.). В этой cвязи актуально pазвитие методичеcкой базы для иccледования pоли водной cpеды в pецепции и ответе оpганизма на дейcтвие cлабыx магнитныx полей. ...
The enhancement of lipid peroxidation in neutrophils (the content of malonic dialdehyde was increased by 10.2%) was shown after an hourly exposition to combined constant (42 µT) and collinear to it weak low-frequency (1,0, 4.4, 16.5 H z; 860 nT) magnetic fields. No correlation was established between this event and the process of functional pre-activation (priming) of neutrophils as a result of the action of combined magnetic fields detected by the enhancement of chemiluminescence in response to the introduction of the bacterial peptide N-formyl-Met-Leu-Phe in the presence of luminol, since ionol (10 µM), an inhibitor of lipid peroxidation, did not reduce the neutrophil priming index in this case. Preliminary addition of the interceptor of singlet oxygen – histidine (0.1 and 1 mM) did not decrease the priming index either. A myeloperoxidase inhibitor – sodium azide (0.1 mM ) exerted a significant inhibitory effect on the chemiluminescence intensity of the
neutrophil suspension, and the priming in the presence of this inhibitor after the action of combined magnetic fields was not developed.
... These effects include an influence on structure formation in water under the action of weak magnetic fields and xenon (the formation of micron size gas-hydrate crystals) [21] and the occurrence of the fluorescent fractions of associates after the CCAMF action and gel filtration [22,23]; CCAMFs affect ionic currents in aqueous solutions of amino acids [24][25][26][27][28][29][30][31] and, as recently shown, CCAMFs change the refractive index in pure water under the action of the hydronic ion and its hydrated form at cyclotron frequencies [32]. A number of experimental data provide a strong argument in favor of the role of the aqueous phase in the biological effects of weak magnetic fields and high-frequency electromagnetic fields ( [33][34][35][36][37][38][39][40] and others). In this regard, the development of a methodical basis for the study of the role of the aquatic environment in the reception and response of an organism to the action of a weak magnetic field is topical. ...
The enhancement of lipid peroxidation in neutrophils (the content of malonic dialdehyde increased by 10.2%) has been shown after a 1-h exposure to a combined constant (42 μT) magnetic field and a weak low-frequency magnetic field (1.0, 4.4, and 16.5 Hz; 860 nT) collinear to it. No correlation was found between this effect and the process of functional pre-activation (priming) of neutrophils as a result of the combined action of magnetic fields detected by chemiluminescence enhancement in response to the introduction of the bacterial peptide N-formyl–Met–Leu–Phe in the presence of luminol, since ionol (10 μM), an inhibitor of lipid peroxidation, did not reduce the neutrophil priming index in this case. Preliminary addition of histidine (0.1 and 1.0 mM), a singlet oxygen scavenger, also did not decrease the priming index. A myeloperoxidase inhibitor, sodium azide (0.1 mM), exerted a significant inhibitory effect on the chemiluminescence intensity of the neutrophil suspension; priming did not develop in the presence of this inhibitor after the action of combined magnetic fields.
... It is based on an interference of quantum states of ions bound to protein inside an idealized cavity [12]; and in spite of the unclear mechanism of MF on the viscosity of an aqueous solution of protein, this phenomenon was explained by the magnetic orientation of small crystals suspended in the solution [13]. In the whole, the mechanism of interaction between magnetic fields and biological structures, if it exists, is still obscure [14][15][16]. ...
The objective of this work is to study the effect of magnetic field (52 mT) on the interaction between two drugs, amlodipine and propranolol, with human serum albumin (HSA) in physiological buffer (pH 7.4) making use of UV absorption and fluorescence and circular dichroism (CD) spectroscopy. The binding constants (K), binding capacities (g) and Hill constants (nH) of the reactions were determined. The results showed that the binding parameters are different in the absence and presence of the magnetic field. The CD spectroscopy revealed that amlodipine induces an increase and propranolol a decrease of α-helix content of HSA. In this case, the application of magnetic field, also, brings about a small change in the CD spectra. The binding distance, r, between donor (HSA) and acceptors (amlodipine and propranolol) was obtained according to Förster theory of non-radiation energy transfer. These results suggest that the magnetic field affects mostly the function of HSA such as drug binding, which plays a key role in drug distribution in the body, and slightly on the structure of HSA.
The effect of magnetic field on surface properties of Bacillus cereus CrA and its EPS was studied by zeta potential and FT-IR spectrum. The weak magnetic fields of 6.0–10.0 mT promoted the predominant strain B. cereus CrA to form EPS. The weak magnetic field of 2.4–10.0 mT could improve the bio-adsorption efficiency of anions by decreasing the negative charge of the intact strain, while the magnetic field of 17.4 mT could increase the negative charge of the strain’s EPS by 20% and be responsible for the bio-adsorption of cations. Magnetic field could affect the band intensity and the slight shifting of peaks and the fluctuation of the bacterial absorption capability depended on the magnetic density. The magnetic field energy could affect the hydroxyl group and carboxyl group by forming hydrogen bonding, which were responsible for the adsorption ability of the strain and its EPS.
It has been shown that the ultralow-frequency extremely weak alternating component of combined magnetic fields (MFs) exhibits a marked antitumor activity. The parameters of this component have been found (frequency 1, 4.4, 16.5 Hz or the sum of these frequencies; intensity 300, 100, 150-300 nT, respectively) at which this MF in combination with a collinear static MF of 42 microT inhibits or suppresses the growth of Ehrlich ascites carcinoma (EAC) in mice. It was shown that the exposure of mice with EAC to combined MFs causes structural changes in some organs (liver, adrenal glands), which are probably due to the total degradation of the tumor tissue. In mice with transplanted EAC, the tumor tissue after exposure to weak MFs was practically absent, as distinct from control animals in which the invasion of the tumor into the adipose tissue surrounding the kidneys, mesenteric lymph nodes, and spermatic appendages was observed. In animals without tumors, no pathological deviations from the norm in the structure of organs and tissues occurred after exposure to weak MF, indicating that this factor per se is not toxic to the organism.
Background
Previous reports indicate altered metabolism and enzyme kinetics for various organisms, as well as changes of neuronal functions and behaviour of higher animals, when they were exposed to specific combinations of weak static and alternating low frequency electromagnetic fields. Field strengths and frequencies, as well as properties of involved ions were related by a linear equation, known as the formula of ion cyclotron resonance (ICR, abbreviation mentioned first by Liboff). Under certain conditions already a aqueous solution of the amino acid and neurotransmitter glutamate shows this effect.
Methods
An aqueous solution of glutamate was exposed to a combination of a static magnetic field of 40 μT and a sinusoidal electromagnetic magnetic field (EMF) with variable frequency (2–7 Hz) and an amplitude of 50 nT. The electric conductivity and dielectric properties of the solution were investigated by voltammetric techniques in combination with non linear dielectric spectroscopy (NLDS), which allow the examination of the dielectric properties of macromolecules and molecular aggregates in water. The experiments target to elucidate the biological relevance of the observed EMF effect on molecular level.
Results
An ion cyclotron resonance (ICR) effect of glutamate previously reported by the Fesenko laboratory 1998 could be confirmed. Frequency resolution of the sample currents was possible by NLDS techniques. The spectrum peaks when the conditions for ion cyclotron resonance (ICR) of glutamate are matched. Furthermore, the NLDS spectra are different under ICR- and non-ICR conditions: NLDS measurements with rising control voltages from 100–1100 mV show different courses of the intensities of the low order harmonics, which could possibly indicate "intensity windows". Furthermore, the observed magnetic field effects are pH dependent with a narrow optimum around pH 2.85.
Conclusions
Data will be discussed in the context with recent published models for the interaction of weak EMF with biological matter including ICR. A medical and health relevant aspect of such sensitive effects might be given insofar, because electromagnetic conditions for it occur at many occasions in our electromagnetic all day environment, concerning ion involvement of different biochemical pathways.
Human subjects respond to low-intensity electric and magnetic fields. If the ability to do so were a form of sensory transduction, one would expect that fields could trigger evoked potentials, as do other sensory stimuli. We tested this hypothesis by examining electroencephalograms from 17 subjects for the presence of evoked potentials caused by the onset and by the offset of 2 G, 60 Hz (a field strength comparable to that in the general environment). Both linear (time averaging) and nonlinear (recurrence analysis) methods of data analysis were employed to permit an assessment of the dynamical nature of the stimulus/response relationship. Using the method of recurrence analysis, magnetosensory evoked potentials (MEPs) in the signals from occipital derivations were found in 16 of the subjects (P<0.05 for each subject). The potentials occurred 109-454 ms after stimulus application, depending on the subject, and were triggered by onset of the field, offset of the field, or both. Using the method of time averaging, no MEPs were detected. MEPs in the signals from the central and parietal electrodes were found in most subjects using recurrence analysis, but no MEPs were detected using time averaging. The occurrence of MEPs in response to a weak magnetic field suggested the existence of a human magnetic sense. In distinction to the evoked potentials ordinarily studied, MEPs were nonlinearly related to the stimulus as evidenced by the need to employ a nonlinear method to detect the responses.
The article discusses the so-called 'kT problem' with its formulation, content, and consequences. The usual formulation of the problem points out the paradox of biological effects of weak low-frequency magnetic fields. At the same time, the formulation is based on several implicit assumptions. Analysis of these assumptions shows that they are not always justified. In particular, molecular targets of magnetic fields in biological tissues may operate under physical conditions that do not correspond to the aforementioned assumptions. Consequently, as it is, the kT problem may not be an argument against the existence of non thermal magnetobiological effects. Specific examples are discussed: magnetic nanoparticles found in many organisms, long-lived rotational states of some molecules within protein structures, spin magnetic moments in radical pairs, and magnetic moments of protons in liquid water.
It has been shown that exposure to weak combined permanent (42 mT) and low-frequency (3-60 Hz) alternating (0.001-0.06 mT) magnetic fields changes the intensity of fluorescence of water and water-salt solutions. The gel filtration of solutions of inorganic salts treated with magnetic fields gives rise to intensively fluorescing fractions. Control solutions not exposed to electromagnetic waves do not exhibit these effects. The results obtained suggest that treatment with weak electromagnetic fields induces structural changes of water solutions, and the manifestations of these changes depend on the conditions of chromatography and chemical composition of solutions under study.
The effect of weak static (DC) and alternating (AC) magnetic fields (MFs), as well as combined (AC/DC) collinear MFs on the intensity of morphogenesis processes in the planarian Dugesia (Girardia) tigrina has been studied. It was found that combined MFs produce a stimulating effect on the fission and regeneration of planarians. Both components of the combined MFs, the direct (DC) and the alternating (AC), are important in the realization of the effects of weak MFs. The practically complete absence of one of the components (DC) reverses the sign of the effect. It was shown that the presence of concomitant background MFs does not substantially influence the effects of combined MFs with a very small AC component (100 nT). The effect of the "zero" field is significant and comparable in magnitude with the effects of combined MFs at effective frequencies. Narrow zones of effective amplitudes (in the region of tens and hundreds of nT) of the AC component of the combined MFs, with the DC component close to the value of the geomagnetic field were found, which alternate with regions where the response of the biological object to the influence is absent.
The experiment was performed to prove that exposure to a relatively weak extremely low frequency (ELF) magnetic field retards tadpoles' development.
Two cohorts of Xenopus laevis laevis (Daudin) tadpoles were exposed during their immature period ( approximately 60 days) to a 50 Hz magnetic field of 63.9 < or = B < or = 76.4 microT rms (root mean square, average values) magnetic flux density in a solenoid. At the same time, as controls, two comparable cohorts were reared in two aquariums remote from the solenoid. Cohorts' degree of development was quantified by daily inspections of animal limbs and attributing them to a stage of the Nieuwkoop and Faber ( 1956 ) classification. The experiment was replicated three times.
(a) Mean developmental rate of exposed cohorts was reduced with respect to controls (0.43 vs. 0.48 stages/day, p < 0.001) starting from early larval stages; (b) Exposure increased the mean metamorphosis period of tadpoles by 2.4 days compared with the controls (p < 0.001); (c) Maturation rates of exposed and control tadpoles changed during maturation period; and (d) Important mortality, malformations or teratogenic effects were not observed in exposed matured tadpoles.
A long-term exposure of X. laevis tadpoles to a relatively weak 50 Hz magnetic field causes a sub-lethal effect that slows down their larval developmental rate and delays their metamorphosis.
It was found that weak magnetic fields (constant 42 microT; variable 0.05 microT; summation of frequencies in the range of 3.58-4.88 Hz) substantially (approximately fourfold) accelerate the hydrolysis of the amyloid beta-protein in aqueous solution. A region of the amyloid beta-protein most sensitive to the action of weak magnetic fields was determined. It is localized between Asp and Ser amino acid residues in positions 7 and 8 of the peptide sequence. It is in this region that the hydrolysis of the molecule of the amyloid beta-protein by the action of magnetic fields predominantly takes place.
Radical recombination following the photodissociation of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone in isotropic solution was monitored using time-resolved infrared spectroscopy. The rate of radical recombination was determined to decrease in the presence of a magnetic field of greater than 5 mT and to increase in the presence of a magnetic field smaller than 5 mT.
It has been shown that the effects of stimulation of germination of wheat seeds by electromagnetic field depend on the degree of membrane tension during imbibition of seeds in sucrose solutions. This provides further confirmation of the influence of electromagnetic fields on the release of proteins from the bound state on the membranes. The prolonged treatment with electromagnetic fields during the imbibition of seeds leads not only to the inhibition of germination of sprouts but also to a decrease in their germinability, which can be as strong as twofold for seeds with the initial low germinability. This is related to the desynchronization of germination processes, caused by the stimulation of the release of proteins and inhibition of another stage during the cell division, the assembly of complex structures. It is noted that the activation of the release of proteins and inhibition of their binding by the action of electromagnetic fields must elevate the cell excitability. The presumably, the excitability of cells determines the effects of magnetic storms and high solar activity on the physiological state of organisms.
This review discusses the application of infrared spectroscopy to the study of proteins. The focus is on the mid-infrared spectral region and the study of protein reactions by reaction-induced infrared difference spectroscopy.