Mansuy D, Chottard J C, Chottard G
Eur J Biochem. 1977 Jun 15;76(2):617-23. doi: 10.1111/j.1432-1033.1977.tb11632.x.
Primary and secondary aliphatic nitro compounds, R2CHNO2, react with myoglobin and hemoglobin, in the presence of sodium dithionite, leading to new complexes with Soret peaks respectively at 425 and 421 nm. These complexes are very stable even after disappearance of the starting nitro compounds and do not exchange their exogenous ligand after 10 h under 1 atm (101 325 Pa) CO. They are low-spin hexacoordinated myoglobin or hemoglobin complexes, as shown by the resonance Raman spectrum of the nitromethane-derived human hemoglobin complex which is similar to those of the known hemoglobin complexes with O2, CO, NO and nitrosobenzene. Evidence has been produced to show that the nitro compounds themselves do not bind to the hemoproteins; we propose that among the reduction derivatives produced in situ by dithionite, the corresponding unstable nitroso monomers, whose nitroso group is isoelectronic with dioxygen, are the actual ligands of the 425-nm or 421-nm-absorbing complexes.
伯脂肪族硝基化合物和仲脂肪族硝基化合物R₂CHNO₂在连二亚硫酸钠存在下与肌红蛋白和血红蛋白发生反应，分别生成在425和421 nm处有Soret峰的新配合物。即使起始硝基化合物消失后，这些配合物仍非常稳定，在1个大气压（101 325帕）的CO条件下10小时后也不会交换其外源配体。它们是低自旋六配位肌红蛋白或血红蛋白配合物，由源自硝基甲烷的人血红蛋白配合物的共振拉曼光谱证明，该光谱与已知的血红蛋白与O₂、CO、NO和亚硝基苯形成的配合物的光谱相似。有证据表明硝基化合物本身并不与血蛋白结合；我们提出，在连二亚硫酸钠原位产生的还原衍生物中，相应的不稳定亚硝基单体（其亚硝基与双氧等电子）是吸收425 nm或421 nm光的配合物的实际配体。
