The reaction of nitrogen monoxide and of nitrite with deoxyhaemocyanin and methaemocyanin of Helix pomatia.
Deoxyhaemocyanin, treated with NO under strictly anaerobic conditions, yielded methaemocyanin and N2O in a fast reaction. In a further slow reaction this methaemocyanin lost its triplet electron paramagnetic resonance (EPR) signal at g = 4 and yielded a nitrosyl derivative with a characteristic g = 2 Cu(II) EPR signal, indicating the binding of a single NO per copper pair. Thus under strictly anaerobic conditions deoxyhaemocyanin and methaemocyanin, treated with NO, gave the same derivative as shown by circular dichroism and EPR spectra. Methaemocyanin yielded, moreover, reversibly a nitrite derivative, characterized by a triplet signal at g = 4 with 7 hyperfine lines.
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D003300:Copper; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds; D006372:Helix, Snails; D006433:Hemocyanins / Q000031:analogs & derivatives; D006863:Hydrogen-Ion Concentration; D009569:Nitric Oxide; D009573:Nitrites; D009609:Nitrous Oxide; D013997:Time Factors
D005290:Ferric Compounds; D009573:Nitrites; C019325:deoxyhemocyanin; C015985:methemocyanin; D009569:Nitric Oxide; D003300:Copper; D006433:Hemocyanins; D009609:Nitrous Oxide