SURFACE-ENHANCED RESONANCE RAMAN-SPECTROSCOPY OF MICROPEROXIDASES AND HORSERADISH-PEROXIDASE ADSORBED ON SILVER HYDROSOL

Surface-enhanced resonance Raman spectra of microperoxidases MP-8, MP-9, MP-11, horseradish peroxidase (HRP) and 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine iron(III) chloride [OEP Fe(III) chloride] molecules adsorbed on silver hydrosol were studied. It was established that when adsorbed MP-8, MP-9, HRP and OEP Fe(III) chloride existed in high-spin state and MP-11 in low-spin state. The absence of spin state conversion in the case of MP-11 is supposed to be related to the formation of intermolecular coordination between the heme iron of one molecule and the NH2 group of Val-11 or Lys-13 of the other. The oxidation state of iron does not change with adsorption.