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1.
Proteinoids have been demonstrated as complexes of amino acid polymers with melanoidin pigments. Some physico-chemical properties of proteinoid pigments were studied in comparison with the standard melanoidins. Proteinoid pigments were able to enhance oxidoreduction and hydrolysis reactions, and their activity was comparable with the activity of the corresponding polyamino acid components or even of the entire proteinoids. The pigmented proteinoids had relatively strong ESR signal indicating the presence of free radicals into melanoidin components. Hypothetical participation of proteinoid melanoidin pigments in prebiotic evolution is discussed.  相似文献   

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1. Comparative additional effects of 24 commercially obtained amino acids and their derivatives were studied by the whole blood clot lysis time (WBCLT) method. D-Arg and L-Lys (greater than 50 micrograms/ml) activated the fibrinolytic system, and poly-L-Glu (mol. wt 6000-90,000) (less than 50 micrograms/ml) were less effective. 2. Poly-L-Arg, poly-L-Lys and poly-(Lys-Ala-Glu-Tyr) accelerated the TPA inhibition in the presence of human plasma. 3. For in vivo experiments, 5 mg of poly-L-Glu were given intravenously to 10 rats. 4. The shortening of WBCLT and elevation of EFA (P less than 0.01) were found after 1 hr administration. 5. The main enzymes which increased in plasma were proved to be the endogenous plasminogen activators with mol. wt higher than 70,000, by zymography.  相似文献   

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Novikov VV  Fesenko EE 《Biofizika》2001,46(2):235-241
It was shown that weak combined magnetic fields (constant field 25-130 microT; variable field 0.01-0.2 microT; the range of effective frequencies of the alternating component 1-10 Hz) substantially increase the rate of hydrolysis of some proteins and peptides (eight various sequences). The concentration dependence of the dynamics of the process and the dependence of the magnitude of the effect on the parameters of the magnetic field. It was found that: (1) the effect is transmitted through a solvent preliminarily treated by magnetic fields and (2) the effect occurs in the presence of inhibitors of proteases and enzymes inactivating peroxides (catalase and horse radish peroxidase with substrate).  相似文献   

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Changes in the excitability of the neuron (amplitude, excitability threshold, rate of action potential transduction), as well as changes in the viscosity of the plasma membrane of the nerve and membranes of subcellular organelles, induced by the action of a weak magnetic field, have been studied by the methods of extracellular registration of membrane potential and combination scattering. It was found that only the threshold of excitability in intact nervous fibers increases by the action of this field. It was proven that the conformation of C40 carotenoids localized not only in plasma membranes but also in subcellular membranes of the neuron changes in a weak magnetic field. It is assumed that the changes in the excitability of the neuron by the action of weak magnetic field are due to changes in the orderliness of membrane lipids and the content of oxygen in the cytoplasm.  相似文献   

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The influence of 8 Hz frequency and 5 mcTl induction changing magnetic fields on the functional state of blood neutrophils, sympathoadrenal system and brain integrative activity in rats with low, middle and high level of mobility was investigated in open test. It was found out that changing magnetic fields provoke the stress-reaction development in rats with low mobile activity. The adaptation which develops in rats with high and middle mobile activity comes later by 5-7 days in high mobility rats.  相似文献   

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Kartashov IuA  Popov IV 《Biofizika》2008,53(2):344-350
It is shown that, under the influence of magnetic field, rotational moments of the same direction appear for all charged particles having the same sign of their charge and freely moving in a thermal fluctuational electromagnetic field in a diamagnetic condensed matter. The magnitude of this rotational moment is proportional to the thermal energy kT and can be substantially increased when the conditions for cyclotron resonance are satisfied. The moments of positively charged particles are directed oppositely to the vector of the magnetic field induction. The so-called "kT problem" has been solved. The evidence for magnetosensitivity is the appearance of rotational moments acting on the particles from the thermal field in the presence of an external magnetic field as a small factor.  相似文献   

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It was shown that weak combined static (42 microT) and low-frequency variable (40 nT; 3-5 Hz) magnetic fields change the intensity of intrinsic fluorescence of some proteins (cytochrome c, bovine serum albumin, horseradish peroxidase, alkaline phosphatase). The effect can be interpreted as a change in the conformational state of the protein in water environment by the action of weak magnetic fields. The dynamics of the process, the concentration dependence, the binding of proteins to the fluorescence probe 1,8-ANS after treatment with magnetic fields, the frequency dependence of these reactions, and the dependence of the effect on the presence of the static constituent of the magnetic field were studied. It was shown that the changes in the intrinsic fluorescence of some enzymes (horseradish peroxidase, alkaline phosphatase) are related to changes in their functional activity. It was found that the effect is partially transferred via a solvent (water, 0.01 M NaCl) preliminarily treated with magnetic field. In the solvent, changes in its intrinsic fluorescence by the action of weak magnetic fields were also registered.  相似文献   

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Ermakov  A. M.  Lednev  V. V. 《Biophysics》2010,55(4):633-636
The effects of weak combined magnetic fields adjusted to the parametric resonance for Ca2+ and K+ and extremely weak alternating magnetic field on the metamorphosis of the mealworm beetle Tenebrio molitor have been studied. It was shown that the exposure of pupas of insects to all above-indicated types of fields stimulates the metamorphosis. However, after the exposure to weak combined magnetic fields adjusted to the parametric resonance for Ca2+ and K+, the number of insects with anomalies increases, which is not observed by the action of the weak alternating magnetic field.  相似文献   

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Ermakov AM  Lednev VV 《Biofizika》2010,55(4):715-719
The effects of weak combined magnetic fields adjusted to the parametric resonance for Ca2+ and K+ and extremely weak alternating magnetic field on the metamorphosis of the meal-worm beetle Tenebrio molitor have been studied. It was shown that the exposure of pupas of insects to all above-indicated types of fields stimulates the metamorphosis. However, after the exposure to weak combined magnetic fields adjusted to the parametric resonance for Ca2+ and K+, the number of insects with anomalies increases, which is not observed by the action of the weak alternating magnetic field.  相似文献   

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Specimen-tilting in an electron microscope was used to determine the three-dimensional architecture of the helical complexes formed with DNA by the closely related single-stranded DNA binding proteins of fd and IKe filamentous viruses. The fd gene 5 protein is the only member of the DNA-helix-destabilizing class of proteins whose structure has been determined crystallographically, and yet a parameter essential to molecular modeling of the co-operative interaction of this protein with DNA, the helix handedness, has not been available prior to this work. We find that complexes formed by titrating fd viral DNA with either the fd or IKe gene 5 protein have a left-handed helical sense. Complexes isolated from Escherichia coli infected by fd virus are also found to be left-handed helical; hence, the left-handed fd helices are not an artefact of reconstitution in vitro. Because the proteins and nucleic acid of the complexes are composed of asymmetric units which cannot be fitted equivalently to right-handed and left-handed helices, these results rule out a previous computer graphics atomic model for the helical fd complexes: a right-handed helix had been assumed for the model. Our work provides a defined three-dimensional structural framework within which to model the protein-DNA and protein-protein interactions of two structurally related proteins that bind contiguously and co-operatively on single-stranded DNAs.  相似文献   

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It has been shown for the first time that retina photoreceptors of the salmon Oncorhynchus masou (masu salmon) fry exposed to a constant magnetic field (80 Gs) in conditions of twilight illumination demonstrated not a twilight reaction, as in the control, but a darkness (scotopic) reaction. The pigment epithelium in this case reacted as to bright light. Under the influence of long wavelength red light, the retinomotor reaction corresponded to partial light adaptation. After the indemnification of the horizontal component (0.1 Gs) of the geomagnetic field, fish retina adapted to complete darkness demonstrated changes that could not be attributed to one of standard conditions of light exposure. Thus, the rods and cones demonstrated a reaction similar to that to twilight, double cones reacted as to complete darkness ("correct" reaction), and PE borrowed a position as at twilight. Apparently, the basic stimuli of the retina reactions were not light but changes of the magnetic field. Based on these results and the results available in literature, the authors offer a new variant of the hypothesis of light-dependent magnetoreception, which is based on the assumption that the liquid crystals of retina pigments are very sensitive receptors of magnetic field and do not require the presence of magnetite crystals. We assume that the layer of retina pigment epithelium participates in the complex process of transformation of a light signal, which takes into account the influence of magnetic field but not simply absorbs light superfluous for photoreceptors. The changes in magnetic field cause a distortion of the liquid crystal line structure of the pigment, which results in the transformation of the light signal acting on the photoreceptors. Monochromatic red light in the same way deforms the response to the native magnetic signal.  相似文献   

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Pulsed electromagnetic fields (PEMFs) have been used extensively in bone fracture repairs and wound healing. It is accepted that the induced electric field is the dose metric. The mechanisms of interaction between weak magnetic fields and biological systems present more ambiguity than that of PEMFs since weak electric currents induced by PEMFs are believed to mediate the healing process, which are absent in magnetic fields. The present study examines the response of human umbilical vein endothelial cells to weak static magnetic fields. We investigated proliferation, viability, and the expression of functional parameters such as eNOS, NO, and also gene expression of VEGF under the influence of different doses of weak magnetic fields. Applications of weak magnetic fields in tissue engineering are also discussed. Static magnetic fields may open new venues of research in the field of vascular therapies by promoting endothelial cell growth and by enhancing the healing response of the endothelium. Bioelectromagnetics 31:296–301, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

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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.  相似文献   

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