Haloperoxidases structure

Some haloperoxidases contain vanadium and a review of vanadium peroxidases has been given (Butler 1998). The structure of the vanadium enzyme in the terrestrial fungus Cur-vularia inaequalis has been determined by x-ray analysis (Messerschmidt et al. 1997), and the apochloroperoxidase possesses, in addition, phosphatase activity that can be rationalized on the basis of the isomorphism of phosphate and vanadate (Renirie et al. 2000). 

It is also of interest to point out that the amino acid sequence and structure of the active site of vanadium haloperoxidases is conserved within several families of phosphatases, with conservation of the amino acids involved in vanadate binding in one and phosphate binding in the other. 

Professor M. R. Maurya is currently heading the Department of Chemistry, IIT Roorkee. He has more than 26 years of teaching and research experience. He had worked in Loyola University of Chicago, USA, Iowa State University, Ames, Iowa, USA, National Chemical Laboratory, Pune, and Pune University Pune, before joining department of Chemistry at IIT Roorkee in 1996 and became full professor in 2008. His current area of research interests include structural and functional models of vanadate-dependent haloperoxidases, coordination polymers and their catalytic study, metal complexes encapsulated in zeolite cages and their catalytic study, polymer-anchored metal complexes and their catalytic study, and medicinal aspects of coordination compounds. So far, he has guided 21 doctoral and 7 Master s theses, co-authored more than 140 research papers in the international refereed journals. 

An empirical method for correlating the oxidation state of a metal ion with the coordination geometry and the bond lengths Bond valence sum analysis has been used in characterizing the structural features of vanadium-dependent haloperoxidases . ... 

The authors analyzed the (limited) data on the basis of homology model derived by considering the X-ray structure of a different type of enzyme, a haloperoxidase... 

Brominated compounds widely occur in marine organisms, particularly seaweeds and invertebrates. Many of them play a defensive role against parasites and predators, and are incorporated by opisthobranch mollusks to this scope from the diet. Bromine is uptaken by seaweeds and invertebrates from bromide dissolved at sparingly 1 mM concentration in seawater. The process is catalyzed by haloperoxidases, which have been characterized both as structure and function (Butler 1997). 

Haloacid dehalogenase(s) 590 mechanism of 590 Haloalkane dehalogenase(s) 591 active site structure 591 Halocyanin 883 Haloperoxidases 855, 889 Hammerhead ribozyme 649, 651s mechanism of action 651 Hammett equation 308... 

The ubiquitous hemoprotein chloroperoxidase (CPO) (1) continues to be of great mechanistic and practical interest following its isolation more than 40 years ago from Caldariomyces fumago (2138). The CPO gene from this filamentous fungus has been isolated and sequenced (2139), an active recombinant CPO has been produced (2140), and the crystal structure of this CPO has been determined (2141, 2142). The fungus Curvularia inaequalis contains a vanadium CPO, which has been characterized (primary and X-ray structure) (Fig. 4.1) (2143-2147), as has the vanadium haloperoxidase from Corallina officinalis (2324). This enzyme has also been studied by density functional theory lending support to the proposed mechanism of action (Scheme 4.1) (2325). A related vanadium CPO, which shares 68% primary structural identity with the Curvularia inaequalis CPO, is produced... 

Weyand M, Hecht H-J, KieP M, Liaud M-F, Vilter H, Schomburg D (1999) X-ray Structure Determination of a Vanadium-dependent Haloperoxidase from Ascophyllum nodosum at 2.0 A Resolution. J Mol Biol 293 595... 

A. Dalby, and M. Isupov, Structural and functional comparisons between vanadium haloperoxidase and add phosphatase enzymes,/. Mol. Recognit. 2002, 15, 291-296. 

Conte, V., O. Bortolini, M. Carraro, and S. Moro. 2000. Models for the active site of vanadium-dependent haloperoxidases Insight into the solution structure of peroxo-vanadium compounds. J. Inorg. Biochem. 80 41 -9. 

Interestingly, there is a close structural correspondence between the active sites of the haloperoxidases and the acid phosphatases that allows both peroxidase and phosphatase activity from the two types of enzymes [49-51], For instance, recombinant acid phosphatases from both Shigella flexneri and Salmonella enterica ser. typhimurium, when substituted by vanadate, are able to oxidize bromide when in the presence of hydrogen peroxide. However, the turnover rate is quite slow, which is in accord with the phosphatase active sites not being optimized for peroxidase activity [52],... 

Messershmidt, A., L. Prade, and R. Wever. 1998. Chloroperoxidase from Curvularia inaequalis x-ray structures of native and peroxide form reveal vanadium chemistry in vanadium haloperoxidases. ACS Symp. Ser. 711 186-201. 

B20. Bolscher, G. J. M., Spectroscopic and structural properties of mammalian haloperoxidases. In Academisch Profeschrift. Drukerij Elinkwijk, Amsterdam, 1986. 

The 3D-structure of PFE is unknown, however it was possible to perform homology modeling based on the solved 3D-structure of a haloperoxidase from Streptomyces aur-eofaciens [25]. This revealed that both mutations are not close to the binding pocket but solely at the periphery of the enzyme [24]. 

The X-ray structures of vanadium bromoperoxidases from the red seaweeds Corallina pilulifera and C. officinalis have also been determined and their structures are almost identical. The native structure of these enzymes is dodecameric and the structure is made up of 6 homo-dimers. The secondary stmcture of the chloroperoxidase from the ftmgus Curvularia inaequalis that will be discussed later can be superimposed with the Corallina hromoperoxidase dimer. Many of the a helices of each chloroperoxidase domain are structurally equivalent to the a helices in the Corallina hromoperoxidase dimer. This is in line with the evolutionary relationship between the haloperoxidases that will be discussed later. The disulfide bridges in the enzyme from A. nodosum are not found in the enzyme from Corallina and the two remaining cysteine residues are not involved in disulfide bonds. Additionally, in this enzyme binding sites are present for divalent cations that seem to be necessary to maintain the stmcture of the active site cleft. All the residues directly involved in the binding of vanadate are conserved in the algal bromoperoxidases. ... 

Clan SC peptidases are a/p hydrolase-fold enzymes that consist of parallel P-strands surrounded by a-helices. The a/p hydrolase-fold provides a versatile catalytic platform that, in addition to achieving proteolytic activity, can either act as an esterase, lipase, dehalogenase, haloperoxidase, lyase, or epoxide hydrolase (18). Six phylogenetically distinct families of clan SC are known, and oifly four of them have known structure. Catalytic amenability of the a/p hydrolase-fold may underlie why clan SC peptidases are the second largest family of serine peptidases in the human genome. Other mechanistic classes need not use the catalytic serine and instead use cysteine or glutamic acid (19). Clan SC peptidases present an identical geometry to the catalytic triad observed in clans PA and SB, yet this constellation is ordered differently in the polypeptide sequence. Substrate selectivity develops from the a-helices that surround the central P-sheet core. Within clan SC, carboxypeptidases from family SIO are unique for their ability to maintain... 

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