Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to o...Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 8x 1014 ions/cm2 to 6x1015 ions/cm2.The treatment of H2O2 and [ CHC13 +CH3 CH2OH ] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of MnSOD in D. radiodurans AS1.633 by N+ beam exposure . These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.展开更多
Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses....Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses.The catalytic activity of the three complexes for disproportionation of O2-was determined by NBT method.The result shows that the complexes have a high SOD-like activity,and the KQ values of complexes 1,2 and 3 are 0.78×107mol-1·L·s-1,1.28×107mol-1,and 1.50×107mol-1L·s-1,respectively.展开更多
基金This work was supported by the National Nature Science Foundation of China! No.19605005
文摘Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 8x 1014 ions/cm2 to 6x1015 ions/cm2.The treatment of H2O2 and [ CHC13 +CH3 CH2OH ] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of MnSOD in D. radiodurans AS1.633 by N+ beam exposure . These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.
文摘Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses.The catalytic activity of the three complexes for disproportionation of O2-was determined by NBT method.The result shows that the complexes have a high SOD-like activity,and the KQ values of complexes 1,2 and 3 are 0.78×107mol-1·L·s-1,1.28×107mol-1,and 1.50×107mol-1L·s-1,respectively.
