Resonance Raman spectroscopic characterization of compound III of lignin peroxidase

• Published in: Biochemistry (Easton) 1990-10, Vol.29 (41), p.9617-9623
• Main Authors: Mylrajan, Muthusamy, Valli, Khadar, Wariishi, Hiroyuki, Gold, Michael H, Loehr, Thomas M
• Format: Article
• Language: English
• Subjects: 550201 - Biochemistry- Tracer Techniques; ABSORPTION SPECTRA; Analytical, structural and metabolic biochemistry; BASIC BIOLOGICAL SCIENCES; Basidiomycota - enzymology; Biological and medical sciences; BOIS; CARBOHYDRATES; CARBOXYLIC ACIDS; CHAMPIGNON; Electron Spin Resonance Spectroscopy - methods; ELECTRONIC STRUCTURE; ENERGY LEVELS; ENZYMES; Enzymes and enzyme inhibitors; ESPECTROMETRIA; EUMYCOTA; EVEN-EVEN NUCLEI; EXCITED STATES; Fundamental and applied biological sciences. Psychology; FUNGI; GEOMETRY; GLOBINS; GLYCOPROTEINS; HETEROCYCLIC ACIDS; HETEROCYCLIC COMPOUNDS; HONGOS; Indicators and Reagents; Isoenzymes - chemistry; Isoenzymes - isolation & purification; ISOTOPES; LASER SPECTROSCOPY; LIGHT NUCLEI; LIGNIN; LIGNINAS; LIGNINE; LIGNINS; Macromolecular Substances; MADERA; MATHEMATICS; MEASURING INSTRUMENTS; MYOGLOBIN; NUCLEI; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; OXIDOREDUCTASES; OXYGEN 18; OXYGEN ISOTOPES; PEROXIDASAS; PEROXIDASES; Peroxidases - chemistry; Peroxidases - isolation & purification; PEROXYDASE; PHANEROCHAETE; PHANEROCHAETE CHRYSOSPORIUM; PIGMENTS; PLANTS; POLYSACCHARIDES; PORPHYRINS; Protein Conformation; PROTEINS; RAMAN SPECTRA; RAMAN SPECTROSCOPY; SACCHARIDES; SPECTRA; SPECTRAL ANALYSIS; SPECTROMETERS; SPECTROMETRIE; SPECTROMETRY; SPECTROSCOPY; Spectrum Analysis, Raman - methods; STABLE ISOTOPES; ULTRAVIOLET SPECTROMETERS; VIBRATIONAL STATES; WOOD
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi00493a016

Resonance Raman (RR) spectra of several compounds III of lignin peroxidase (LiP) have been measured at 90 K with Soret and visible excitation wavelengths. The samples include LiPIIIa (or oxyLiP) prepared by oxygenation of the ferrous enzyme, LiPIIIb generated by reaction of the native ferric enzyme with superoxide, LiPIIIc prepared from native LiP plus H2O2 followed by removal of excess peroxide with catalase, and LiPIII* made by addition of excess H2O2 to the native enzyme. The RR spectra of these four products appear to be similar and, thus, indicate that the environments of these hexacoordinate, low-spin ferriheme species must also be very similar. Nonetheless, the Soret absorption band of LiPIII* is red-shifted by 5 nm from the 414-nm maximum common to LiPIIIa, -b, and -c [Wariishi, H., & Gold, M.H. (1990) J. Biol. Chem. 265, 2070-2077]. Analysis of the iron-porphyrin vibrational frequencies indicates that the electronic structures for the various compounds III are consistent with an FeIIIO2.-formulation. The spectral changes observed between the oxygenated complex and the ferrous heme of lignin peroxidase are similar to those between oxymyoglobin and deoxymyoglobin. The contraction in the core sizes in compound III relative to the native peroxidase is analyzed and compared with that of other heme systems. EPR spectra confirm that the high-spin ferric form of the native enzyme, with an apparent g = 5.83, is converted into the EPR-silent LiPIII* upon addition of excess H2O2. Its magnetic behavior may be explained by anti-ferromagnetic coupling between the low-spin FeIII and the superoxide ligand.