Institute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russian Federation, Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432 Chernogolovka, Russian Federation, Moscow State University, 119992 Moscow, Russian Federation, Russian National Medical University, 117997 Moscow, Russian Federation and Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
Nucleic Acids Res. 2013 Sep;41(17):8300-7. doi: 10.1093/nar/gkt537. Epub 2013 Jul 13.
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).
在催化部位中,用同位素离子(24)Mg(2+)、(25)Mg(2+)和(26)Mg(2+)检测到了聚合酶β催化的 DNA 合成速率的磁同位素和磁场效应。在没有磁场的情况下,具有无自旋、非磁性核(24)Mg 和(26)Mg 的聚合酶β携带(24)Mg(2+)和(26)Mg(2+)离子的酶活性没有差异。然而,具有磁性核(25)Mg 的(25)Mg(2+)离子被证明相对于聚合酶β与(24)Mg(2+)和(26)Mg(2+)离子的酶活性抑制了 2 到 3 倍。这种同位素依赖性直接表明,在 DNA 合成中存在磁质量独立的同位素效应。具有分别携带磁性(67)Zn 和非磁性(64)Zn 核的 Zn(2+)离子的聚合酶β也表现出类似的效应。提出了一种新的离子自由基 DNA 合成机制来解释这些效应。镁催化的 DNA 合成的磁场依赖性与提出的离子自由基机制完全一致。指出磁同位素和磁场效应可用于医学用途(经颅磁治疗认知障碍、细胞增殖、控制癌细胞等)。