title: E.p.r. studies of photolysis of nitrosyl haemoglobin at low temperatures.
abstract: Photolysis of HbNO has been studied from 6.2 K to 15.5 K by electron spin resonance during and after continuous illumination. Non-exponential kinetics of both dissociation and reassociation of NO was observed. The prolonged illumination separates the fast and slow ligands. This picture is consistent with NO tunnelling from two sites at different distances from the bound position. This result is obtained using a model of a sum of two exponentials or of conformational substates.
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, Rua Xavier Sigaud, Rio de Janeiro, Brasil.
authors.forename: M P
authors.initials: MP
authors.lastname: Linhares
authors.forename: L J
authors.initials: LJ
authors.lastname: el-Jaick
authors.forename: G
authors.initials: G
authors.lastname: Bemski
authors.forename: E
authors.initials: E
authors.lastname: Wajnberg
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D010782:Photolysis; D011487:Protein Conformation; D013696:Temperature
chemical_list: D006454:Hemoglobins; C008657:nitrosyl hemoglobin