Horseradish mutant

The uses and applications of horseradish peroxidase in organic synthesis have been reviewed (260, 261). As a reagent it offers several advantages, including wide commercial availability, good stability under a range of conditions, and broad substrate specificity. Future developments are likely to focus on the increased use of site-directed mutants of HRP C to improve stereo- and enantiospecificity in reactions of interest. As yet these enzymes are not available commercially. 

Miller VP, Goodin DB, Friedman AE et al (1995) Horseradish peroxidase Phel72Tyr mutant. Sequential formation of Compound I with a porphyrin radical cation and a protein radical. J Biol Chem 270 181413-181419... 

Morimoto A, Tanaka M, Takahashi S et al (1998) Detection of a tryptophan radical as an intermediate species in the reaction of horseradish peroxidase mutant Phe221Trp and hydrogen peroxide. J Biol Chem 273 14753-14760... 

Smulevich G, Paoli M, Burke JF et al (1994) Characterization of recombinant horseradish peroxidase C and three site-directed mutants, F41V, F41W, and R38K by resonance Raman spectroscopy. Biochemistry 33 7398-7407... 

Newmyer SL, Ortiz de Montellano PR (1995) Horseradish peroxidase His-42 -> Ala, His-42 -> Val, and Phe-41 -> Ala mutants. Histidine catalysis and control of substrate access to the heme iron. J Biol Chem 270 19430-19438... 

Colas C, Ortiz de Montellano PR (2004) Horseradish peroxidase mutants that autocataly-tically modify their prosthetic heme group. Insights into mammalian peroxidase heme-protein covalent bonds. J Biol Chem 279 24131-24140... 

Ozaki S-I, Ortiz de Montellano PR (1995) Molecular engineering of horseradish peroxidase thioether sulfoxidation and styrene epoxidation by Phe-41 leucine and threonine mutants. J Am Chem Soc 117 7056-7064... 

Newmyer SL, Ortiz de Montellano PR (1996) Rescue of the catalytic activity of an H42A mutant of horseradish peroxidase by exogenous imidazoles. J Biol Chem 271 14891-14896... 

Tanaka M, Ishimori K, Mukai M, Kitagawa T, Morishima I (1997) Catalytic activities and structural properties of horseradish peroxidase distal His42 -> Glu or Gin mutant. Biochemistry 36 9889-9898... 

Hiner AN, Hemandez-Ruiz J, Garcia-Canovas F et al (1995) A comparative study of the inactivation of wild-type, recombinant and two mutant horseradish peroxidase isoenzymes C by hydrogen peroxide and m-chloroperoxybenzoic acid. Eur J Biochem 234 506-512... 

Howes BD, Brissett NC, Doyle WA et al (2005) Spectroscopic and kinetic properties of the horseradish peroxidase mutant T171S. Evidence for selective effects on the reduced state of the enzyme. FEBS J 272 5514-5521... 

Smith AT, Sanders SA, Thomeley RNF et al (1992) Characterisation of a haem active-site mutant of horseradish peroxidase, Phe41 Val, with altered reactivity towards hydrogen peroxide and reducing substrates. Eur J Biochem 207 507-519... 

With the ELISA-Hke competition assay, it is possible to determine and compare the competitive potential of different chemokines for the same GAG ligand. Instead of a capturing antibody, as it is used in a classical ELISA, GAGs are coated on specially prepared GAG-binding plates (Iduron) that adsorb GAGs without further chemical modifications while retaining their natural protein-binding characteristics. Biotinylated chemokines are incubated on these plates and can be fiirther competed off with other nonlabeled chemokines, proteins, or mutants. Therefore, biotinylation of the chemokines is an essential first step. After competition, the nondisplaced biotinylated chemokine is detected with streptavidin horseradish peroxidase... 

Feeding experiments with H- and " C-labeled precursors in leaves of horseradish Armoracia lapathifolia) demonstrated the stereospecific removal of the 4-/7/ c>-5-hydrogen of homomethionine during the biosynthesis of sinigrin. The fate of the 5-hydrogens has also been established by H-NMR (Fig. 17.5) (Dewick, 1984). An overall anti process is involved. Mutants of Arabidopsis thaliana which lack the ability to extend the carbon chain of methionine beyond the homomethionine stage have been reported (Davin et al., 1988). 

A. Morimoto, M. Tanaka, S. Takahashi, K. Ishimori, H. Hori, I. Morishima, Detection of a Tryptophan Radical as an Intermediate Species in the Reaction of Horseradish Peroxidase Mutant (Phe-221 Trp) and Hydrogen Peroxide. J. Biol. Chem., 273 (1998) 14753-14760. 

Newmyer, S.L. and de Montellano, P.R.O. (1996) Rescue of the horseradish peroxidase His-170/Ala mutant activity by imidazole importance of proximal ligand tethering. Biochemistry, 35, 12788-12795. 

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