PHOTOINACTIVATION OF SPINACH NITRATE REDUCTASE SENSITIZED BY FLAVIN MONONUCLEOTIDE. EVIDENCE FOR THE INVOLVEMENT OF SINGLET OXYGEN
PHOTOINACTIVATION OF SPINACH NITRATE REDUCTASE SENSITIZED BY FLAVIN MONONUCLEOTIDE. EVIDENCE FOR THE INVOLVEMENT OF SINGLET OXYGEN
复制标题
黄素单核苷酸致敏的菠菜硝酸还原酶的光灭活。
DOI：
--
复制
发表时间：
1982
期刊：
影响因子：
--
通讯作者：
P. Aparicio
中科院分区：
文献类型：
--
作者：
M. A. Vargas;S. G. Maurĩno;J. Maldonado;P. Aparicio
摘要菠菜硝酸还原酶复合物的所有活性在黄素单核苷酸肽存在下被蓝光照射而不可逆地失活。光失活需要氧气，并防止乙二胺四乙酸和还原烟酰胺腺嘌呤二核苷酸，但不是由超氧化物歧化酶加过氧化氢酶。另一方面，失活显着增强，在77%的氘化水，它是由单线态氧淬灭剂叠氮化物，组氨酸和色氨酸抑制。所有这些结果表明，单线态氧产生的光吸收的黄素单胞苷，而不是激发黄素单胞苷或其他氧物种，是主要的代理人参与的光氧化失活的酶。
Abstract All the activities of the nitrate reductase complex from spinach are irreversibly inactivated by irradiation of the enzyme with blue light in the presence of flavin mononucleotide. The photoinactivation requires oxygen and is prevented by ethylenediaminetetraacetic acid and by reduced nicotinamide adenine dinucleotide, but not by superoxide dismutase plus catalase. On the other hand, the inactivation is markedly enhanced in 77% deuterated water and it is suppressed by the singlet oxygen quenchers azide, histidine and tryptophan. All these results suggest that singlet oxygen generated by light absorption by flavin mononucleotide, rather than excited flavin mononucleotide or other oxygen species, is the primary agent involved in the photooxidative inactivation of the enzyme.