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Peroxidases are ubiquitous enzymes that catalyze a variety of oxygen-transfer reactions and are thus potentially useful for industrial and biomedical applications. Over the last decade, several studies have shown that peroxidases isolated from the leaves of different kinds of palm trees such as the royal palm (Roystonea regia), the date palm (Phoenix dactylifera), the African oil palm (Elaeis guineensis), the ruffle palm (Aiphanes cariotifolia) and the windmill palms (Trachycarpus fortunei and Chamaerops excelsa) exhibit higher activity and stability than commercially available peroxidases isolated from, for example, horseradish roots (Armoracia rusticana) and soybean (Glycine max). Here, the structure, thermal denaturation, and the catalytic cycle of peroxidases from palm trees are reviewed and compared with those of other plant peroxidases. In addition, we report the biotechnological potential of palm peroxidases and their implications in cellular aging and diseases, such as Refsum’s and Alzheimer’s diseases. This paper summarizes the main characteristics of the palm peroxidases studied.

Acta Crystallogr Sect F Struct Biol Cryst Commun. 2008 Jul 1;64(Pt 7):593-5 Native zinc/cobalt-containing ATP sulfurylase (ATPS; EC 2.7.7.4; MgATP: sulfate adenylyltransferase) from Desulfovibrio desulfuricans ATCC 27774 was purified to homogeneity and crystallized. The orthorhombic crystals diffracted to beyond 2.5 A ° resolution and the X-ray data collected should allow the determination of the structure of the zinc-bound form of this ATPS. Although previous biochemical studies of this protein indicated the presence of a homotrimer in solution, a dimer was found in the asymmetric unit. Elucidation of this structure will permit a better understanding of the role of the metal in the activity and stability of this family of enzymes.

Bioinorganic Chemistry and Applications Volume 3 (2005), Issue 1-2, Pages 81-91 Two proteins were purified and preliminarily characterized from the soluble extract of cells (310 g, wet weight) of the aminolytic and peptidolytic sulfate-reducing bacterium Desulfovibrio (D.) aminophilus DSM 12254. The iron-sulfur flavoenzyme adenylylsulfate (adenosine 5"-phosphosulfate, APS)reductase, a key enzyme in the microbial dissimilatory sulfate reduction, has been purified in three chromatographic steps(DEAE-Biogel A, Source 15, and Superdex 200 columns). It contains two different subunits with molecular masses of 75 and 18 kDa. The fraction after the last purification step had a purity index (A278 ,m/A388 nm) of 5.34, which was used for further EPR spectroscopic studies. The D. aminophilus APS reductase is very similar to the homologous enzymes isolated from D. gigas and D. desulfuricans ATCC 27774. A tetraheme cytochrome c3 (His-heme iron-His) has been purified in three chromatographic steps (DEAE- Biogel A,Source 15, and Biogel-HTP columns) and preliminarily characterized. It has a purity index ([A.s.s3 nm" A570 nm]rcd/m280nm ox) of 2.9 and a molecular mass of around 15 kDa, and its spectroscopic characterization(NMR and EPR) has been carried out. This hemoprotein presents similarities with the tetraheme cytochrome c3 from Desulfomicrobium (Des.) norvegicurn (NMR spectra, and N-terminal amino acid sequence).

A Thesis submitted at the Faculty Science and Technology of the New University of Lisbon for a degree in Doctor of Philosophy in Biochemistry with specialization in Physical Biochemistry (fellowship BD SFRH/BD/24744/05)- Foundation for Science and Technology