Stable Magnetic Isotopes and Reliability of Biomolecular Nanoreactors


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The trend of nanoscaling brings engineering down to the dimensions of molecular structures but in so doing poses also the problem of how to create the reliable system from the molecular components which experience permanent thermal, mechanical and environmental fluctuations. Reliability (“robustness”) is defined as the ability of a device to perform its function for a given time under given conditions (Grodzinsky et al., 1986). Fortunately, engineers may learn wisdom by the examples of Nature (“bionics”), to achieve the high systems reliability while dealing with unreliable components. There are several lines of creating reliable devices from unreliable functional elements in engineering. The main line of creating reliable devices from unreliable components in living systems is prophylaxis of failures, first and foremost, the regular preventive maintenance of functional components. The nuclear spin magnetic moments of the stable magnetic isotopes can afford such the prophylactic effects in living cells. For example, among three stable magnesium isotopes, Mg-24, Mg-25 and Mg-26 with natural abundance 78.99, 10.00 and 11.01 %, only Mg-25 has the nuclear spin (I = 5/2) and, therefore, the nuclear magnetic moment. Two other isotopes are spinless (I = 0) and, hence, have no magnetic moment. We have revealed the isotope differences in quantitative parameters of growth of Escherichia coli on the media contained different isotopes of magnesium. For the bacteria supplied with the magnetic isotope, Mg-25, the length of the adaptation period (lag-phase) to novel liquid nutrient media was found to be essentially shorter than the adaptation period for the bacteria supplied with the nonmagnetic isotopes, Mg-24 or Mg-26. On the solid nutrient media the cells which were previously enriched with Mg-25 have demonstrated the essentially higher viability (determined by counting colony forming units) by comparison with the cells which were previously enriched with Mg-24 or Mg-26. These data document, for the first time, the magnetic isotope effect of magnesium-25 in vivo (Koltover et al., 2011). Furthermore, there is the evidence that the cells enriched with the magnetic Mg-25 produce less superoxide free radicals as the faulty by-products of respiration metabolism by comparison with the cells enriched with the nonmagnetic isotopes Mg-24 and Mg-26. In essence, the magnetic field of the Mg-25 nucleus prevents the free-radical failures in the cellular biomolecular nanoreactors. The preventive antioxidant effect of Mg-25 opens the way toward novel medicine based on this magnetic isotope, including anti-aging drugs and radio-protectors. Apart from magnesium, there are many other elements which have both kinds of stable isotopes, nonmagnetic and magnetic ones, among them – carbon, oxygen, calcium, iron, zinc, etc. For example, it was found that deuterated polyunsaturated fatty acids, being much more resistant to autoxidation reactions because of the isotope effect, protect yeast cells from oxidative stress (Hill et al., 2011). Thus, on the nuclear spin-catalysis background, stable magnetic isotopes hold considerable promise for the magnetic-field control over efficiency and reliability of molecular and biomolecular nanoreactors in nanomedicine and nanoengineering.

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Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2011: Bio Sensors, Instruments, Medical, Environment and Energy
Published: June 13, 2011
Pages: 482 - 485
Industry sector: Medical & Biotech
Topics: Biomaterials
ISBN: 978-1-4398-7138-6