title: Strong vibronic coupling in heme proteins.
abstract: We report the near infrared absorption spectra of cyanomethemoglobin and cyanometmyoglobin in two different solvents (deuterated solutions containing 65% v/v glycerol(OD)3 or 65% v/v ethylene glycol(OD)2). At 25 K the spectra show a clearly resolved fine structure that can be accounted for by considering a strong coupling of the porphyrin-to-iron charge transfer transitions with a single vibrational mode at 365 cm-1. The coupling constants depend on both the specific electronic transition and the protein surrounding the chromophore, indicating once more the specificity of heme globin interactions.
authors.affiliation: Istituto di Fisica dell'Università, Palermo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Leone
authors.forename: A
authors.initials: A
authors.lastname: Cupane
authors.forename: E
authors.initials: E
authors.lastname: Vitrano
authors.forename: L
authors.initials: L
authors.lastname: Cordone
mesh_terms: D006801:Humans; D008706:Methemoglobin / Q000031:analogs & derivatives* / Q000737:chemistry; D008786:Metmyoglobin / Q000031:analogs & derivatives* / Q000737:chemistry; D013055:Spectrophotometry, Infrared
chemical_list: C007169:cyanomethemoglobin; C007177:cyanometmyoglobin; D008786:Metmyoglobin; D008706:Methemoglobin