| enzymatic properties of immobilized beta-galactosidase from curvularia inaequalis. | beta-galactosidase (ec 3.2.1.23) from fungus curvularia inaequalis was modified by active brilliant orange kh and adsorbed on deae-sephadex a-50. the lactose hydrolysis was studied in a continous flow on the column packed with the immobilized enzyme. the ph and temperatures optima for the substrate hydrolysis by the immobilized enzyme were shown to remain unchanged. a certain destabilizing effect of the matrix on the enzyme resistance to hear denaturation was observed. the activation parameters ... | 1977 | 15660 |
| [optimization of the conditions for beta-galactosidase biosynthesis in eukaryotes]. | liquid whey can be subsituted by dry whey in the growth medium for saccharomyces fragilis producing endocellular beta-galactosidase. the total biosynthesis of beta-galactosidase by the yeast on the medium containing dry whey can be increased by 40-50 percent as a result of additional stepwise introduction of lactose into the medium or optimization of the medium by mathematical planning of the experiment. constructive metabolism of the yeast is not correlated with the rate of biosynthesis of beta ... | 1978 | 418313 |
| [modification and immobilization of beta-galactosidase]. | beta-galactosidase from fungus curvularia inaequalis was modified by a chlortriazin dye active bright-orange kh. the modified enzyme contained two molecules of dye per one molecule of protein. the incorporation of six sulfuric groups with remains of the dye resulted in a slight decrease of the acid protein isoelectric point. the catalytic activity of the modified protein remains practically unchanged. the coloured protein is firmly absorbed on anionites. preparations of immobilized beta-galactos ... | 1976 | 987807 |
| [immobolization of beta-galactosidase on silochrome]. | beta-galactosidase (beta-d-galactoside galactohydrolase 3.2.1.23) from curvularia inaequalis was immobilized by glutaric dialdehyde on gamma-aminopropyl triethoxysilane treated porous siliceous carrier silochrome. from the crude preparation with a specific activity of 3.1 u/mg immobilized beta-galactosidase with an activity of 113 u/g was obtained. the immobilized enzyme did not show significant changes in its enzymic properties. the column filled with the resultant preparation and used to hydro ... | 1976 | 1033546 |
| [purification and properties of beta-galactosidase from fungus, curvularia inaequalis]. | highly purfied beta-galactosidase from fungus curvularia inaequalis cultural fluid with a specific activity of 50 units per mg of protein was obtained by 2-fold purification of the enzyme, using chromatography on deae-cellulose and on hydroxylapatite. the enzyme was found to hydrolyze o-nitrophenyl-beta-d-galactopyranoside (ph optimum of 3.7--4.5) and lactose (ph optimum 3.9--5.3). the isoelectric point was observed at ph 4.4 the temperature optimum was 60 degrees c. the molecular weight (115 00 ... | 1976 | 1051894 |
| amperometric bi-enzyme based biosensor for the detection of lactose--characterization and application. | based on the glucose oxidase-beta-galactosidase sequence an enzyme probe for the specific determination of lactose has been developed. beta-galactosidases from different sources have been compared, the sensor containing beta-galactosidase from curvularia inaequalis has been characterized in respect of optimal ph, enzyme loading, apparent activity and functional stability. the response of the bi-enzyme probe depends linearly on lactose concentration between 0.02 and 3.00 mmol dm-3. the applicatio ... | 1990 | 1367478 |
| isolation and characterization of a novel nonheme chloroperoxidase. | chloroperoxidase, purified from the fermentation of curvularia inaequalis, had a molecular weight of approximately 240,000 and was composed of 4 subunits of identical molecular weight (mr 66,000). the enzyme was specific for i-, br- and cl-, and inactive toward f-. the optimum ph of the enzyme was centered around 5.0. x-ray fluorescence revealed that the enzyme contained 2.2 atoms of zinc and 0.7 atom of fe per molecule of protein. the enzyme had no heme-like compound as a prosthetic group, maki ... | 1987 | 3814138 |
| primary structure and characterization of the vanadium chloroperoxidase from the fungus curvularia inaequalis. | using reverse transcription of messenger rna followed by amplification using the polymerase chain reaction, three overlapping cdna fragments encompassing the encoding sequence of the vanadium chloroperoxidase from the fungus curvularia inaequalis were isolated and sequenced. the sequence was confirmed by dna sequence analysis of genomic dna. the deduced amino acid sequence predicts a protein of 609 residues with a mass of 67488 da. competitive reverse-transcription polymerase chain reaction anal ... | 1995 | 7744081 |
| the stability and steady-state kinetics of vanadium chloroperoxidase from the fungus curvularia inaequalis. | in this article we report on the steady-state kinetics of the chlorination and the stability of the vanadium chloroperoxidase from the fungus curvularia inaequalis. the data show that the kinetics of this enzyme resemble that of the vanadium bromoperoxidase from the seaweed ascophyllum nodosum. at low ph, chloride inhibited the enzyme, but the inhibition was of a dual nature. at ph 4.1 a mixed type of inhibition by chloride with respect to hydrogen peroxide was observed whereas at ph 3.1 the nat ... | 1994 | 7925432 |
| the vanadium chloroperoxidase from the fungus, curvularia inaequalis. evidence for the involvement of a histidine residue in the binding of vanadate. | the binding of vanadate to the novel vanadium chloroperoxidase from c. inaequalis was investigated. reconstitution experiments of apo-chloroperoxidase by vanadate at different ph values showed that in the ph 6-7 range an acid/base group is present which affects the binding of the vanadate. it is proposed that this group is a histidine. this hypothesis was tested by specifically modifying this residue using diethylpyrocarbonate. in the apo-enzyme 9 histidines were modified, whereas in the holo-en ... | 1993 | 8262237 |
| the chloroperoxidase from the fungus curvularia inaequalis; a novel vanadium enzyme. | the presence of vanadium-containing bromoperoxidases in various types of seaweed is well-documented. we now report that the terrestrial fungus curvularia inaequalis excretes a novel chloroperoxidase which also contains vanadium as a prosthetic group. the chloroperoxidase is excreted in the medium as the only protein and is, therefore, almost purely obtained. atomic absorption spectroscopy measurements showed that the chloroperoxidase contained vanadium, which was essential for enzymatic activity ... | 1993 | 8381670 |
| x-ray structure of a vanadium-containing enzyme: chloroperoxidase from the fungus curvularia inaequalis. | the chloroperoxidase (ec 1.11.1.-) from the fungus curvularia inaequalis belongs to a class of vanadium enzymes that oxidize halides in the presence of hydrogen peroxide to the corresponding hypohalous acids. the 2.1 a crystal structure (r = 20%) of an azide chloroperoxidase complex reveals the geometry of the catalytic vanadium center. azide coordinates directly to the metal center, resulting in a structure with azide, three nonprotein oxygens, and a histidine as ligands. in the native state va ... | 1996 | 8552646 |
| identification of a novel phosphatase sequence motif. | we have identified a novel, conserved phosphatase sequence motif, kxxxxxxrp-(x12-54)-psgh-(x31-54)-srxxxxx hxxxd, that is shared among several lipid phosphatases, the mammalian glucose-6-phosphatases, and a collection of bacterial nonspecific acid phosphatases. this sequence was also found in the vanadium-containing chloroperoxidase of curvularia inaequalis. several lines of evidence support this phosphatase motif identification. crystal structure data on chloroperoxidase revealed that all three ... | 1997 | 9041652 |
| implications for the catalytic mechanism of the vanadium-containing enzyme chloroperoxidase from the fungus curvularia inaequalis by x-ray structures of the native and peroxide form. | implications for the catalytic mechanism of the vanadium-containing chloroperoxidase from the fungus curvularia inaequalis have been obtained from the crystal structures of the native and peroxide forms of the enzyme. the x-ray structures have been solved by difference fourier techniques using the atomic model of the azide chloroperoxidase complex. the 2.03 a crystal structure (r = 19.7%) of the native enzyme reveals the geometry of the intact catalytic vanadium center. the vanadium is coordinat ... | 1997 | 9165086 |
| the regulation of the vanadium chloroperoxidase from curvularia inaequalis. | the effects of carbon and nitrogen source on the regulation of the vanadium chloroperoxidase secreted by the fungus curnularia inaequalis were investigated. the addition of glucose showed a repressing effect on both the observed messenger rna level and the measured enzyme activities, whereas the addition of glutamate as nitrogen source and the addition of both glutamate and glycerol had no effect. addition of vanadate had no effect on the level of mrna. eight hundred base pairs of the upstream p ... | 1997 | 9177485 |
| a new model for the membrane topology of glucose-6-phosphatase: the enzyme involved in von gierke disease. | very recently we have proposed [hemrika et al. (1997) proc. natl. acad. sci. usa 94, 2145-2149] that the active site of the vanadate-containing chloroperoxidase from the fungus curvularia inaequalis, of which the tertiary structure is known, is structurally very similar to that of the membrane-bound mammalian glucose-6-phosphatases for which no structural data are available. the proposed active site of glucose-6-phosphatase, however, is incompatible with the six transmembrane-helix topology mode ... | 1997 | 9224681 |
| cloning and expression of the gene for a vanadium-dependent bromoperoxidase from a marine macro-alga, corallina pilulifera. | the cdnas for a vanadium-dependent bromoperoxidase were cloned from a marine macro-alga, corallina pilulifera. the open reading frame of one clone (bpo1) encoded a protein of 598 amino acids with a calculated molecular mass of 65312 da in good agreement with that of 64 kda determined for the native enzyme. the deduced amino acid sequence coincided well with partial sequences of peptide fragments of the enzyme. from the same cdna library we also isolated another cdna clone (bpo2) encoding a prote ... | 1998 | 9645486 |
| isolation, characterization, and primary structure of the vanadium chloroperoxidase from the fungus embellisia didymospora. | here we describe the isolation, purification, and basic kinetic parameters of a vanadium type chloroperoxidase from the hyphomycete fungus embellisia didymospora. the enzyme proved to possess similar high substrate affinities, a km of 5 microm for a bromide, 1.2 mm for a chloride, and 60 microm for a hydrogen peroxide, as those of the vanadium chloroperoxidase from curvularia inaequalis, although with lower turnover rates for both cl- and br-. substrate bromide was also found to inhibit the enzy ... | 1998 | 9722573 |
| heterologous expression of the vanadium-containing chloroperoxidase from curvularia inaequalis in saccharomyces cerevisiae and site-directed mutagenesis of the active site residues his(496), lys(353), arg(360), and arg(490). | the vanadium-containing chloroperoxidase from the fungus curvularia inaequalis is heterologously expressed to high levels in the yeast saccharomyces cerevisiae. characterization of the recombinant enzyme reveals that this behaves very similar to the native chloroperoxidase. site-directed mutagenesis is performed on four highly conserved active site residues to examine their role in catalysis. when the vanadate-binding residue his(496) is changed into an alanine, the mutant enzyme loses the abili ... | 1999 | 10446144 |
| x-ray crystal structures of active site mutants of the vanadium-containing chloroperoxidase from the fungus curvularia inaequalis. | the x-ray structures of the chloroperoxidase from curvularia inaequalis, heterologously expressed in saccharomyces cerevisiae, have been determined both in its apo and in its holo forms at 1.66 and 2.11 a resolution, respectively. the crystal structures reveal that the overall structure of this enzyme remains nearly unaltered, particularly at the metal binding site. at the active site of the apo-chloroperoxidase structure a clearly defined sulfate ion was found, partially stabilised through elec ... | 1999 | 10499093 |
| x-ray structure determination of a vanadium-dependent haloperoxidase from ascophyllum nodosum at 2.0 a resolution. | the homo-dimeric structure of a vanadium-dependent haloperoxidase (v-bpo) from the brown alga ascophyllum nodosum (ec 1.1.11.x) has been solved by single isomorphous replacement anomalous scattering (siras) x-ray crystallography at 2.0 a resolution (pdb accession code 1qi9), using two heavy-atom datasets of a tungstate derivative measured at two different wavelengths. the protein sequence (swissprot entry code p81701) of v-bpo was established by combining results from protein and dna sequencing, ... | 1999 | 10543953 |
| peroxidase and phosphatase activity of active-site mutants of vanadium chloroperoxidase from the fungus curvularia inaequalis. implications for the catalytic mechanisms. | mutation studies were performed on active-site residues of vanadium chloroperoxidase from the fungus curvularia inaequalis, an enzyme which exhibits both haloperoxidase and phosphatase activity and is related to glucose-6-phosphatase. the effects of mutation to alanine on haloperoxidase activity were studied for the proposed catalytic residue his-404 and for residue asp-292, which is located close to the vanadate cofactor. the mutants were strongly impaired in their ability to oxidize chloride b ... | 2000 | 10766783 |
| x-ray structures of a novel acid phosphatase from escherichia blattae and its complex with the transition-state analog molybdate. | the structure of escherichia blattae non-specific acid phosphatase (eb-nsap) has been determined at 1.9 a resolution with a bound sulfate marking the phosphate-binding site. the enzyme is a 150 kda homohexamer. eb-nsap shares a conserved sequence motif not only with several lipid phosphatases and the mammalian glucose-6-phosphatases, but also with the vanadium-containing chloroperoxidase (cpo) of curvularia inaequalis. comparison of the crystal structures of eb-nsap and cpo reveals striking simi ... | 2000 | 10835340 |
| crystal structure of dodecameric vanadium-dependent bromoperoxidase from the red algae corallina officinalis. | the three-dimensional structure of the vanadium bromoperoxidase protein from the marine red macroalgae corallina officinalis has been determined by single isomorphous replacement at 2.3 a resolution. the enzyme subunit is made up of 595 amino acid residues folded into a single alpha+beta domain. there are 12 bromoperoxidase subunits, arranged with 23-point group symmetry. a cavity is formed by the n terminus of each subunit in the centre of the dodecamer. the subunit fold and dimer organisation ... | 2000 | 10843856 |
| oxidation reactions catalyzed by vanadium chloroperoxidase from curvularia inaequalis. | vanadium haloperoxidases have been reported to mediate the oxidation of halides to hypohalous acid and the sulfoxidation of organic sulfides to the corresponding sulfoxides in the presence of hydrogen peroxide. however, traditional heme peroxidase substrates were reported not to be oxidized by vanadium haloperoxidases. surprisingly, we have now found that the recombinant vanadium chloroperoxidase from the fungus curvularia inaequalis catalyzes the oxidation of 2,2'-azino-bis(3-ethylbenzthiazolin ... | 2000 | 10885468 |
| enantioselective sulfoxidation catalyzed by vanadium haloperoxidases. | vanadium haloperoxidases catalyze the oxidation of halides by hydrogen peroxide to produce hypohalous acid. we demonstrate that these enzymes also slowly mediate the enantioselective oxidation of organic sulfides (methyl phenyl sulfide, methyl p-tolyl sulfide, and 1-methoxy-4 (methylthio)benzene) to the corresponding sulfoxides (turnover frequency 1 min(-)(1)). the vanadium bromoperoxidase from the brown seaweed ascophyllum nodosum converts methyl phenyl sulfide to the (r)-enantiomer of the sulf ... | 1998 | 11670813 |
| production, characterization and properties of polysaccharide depolymerizing enzymes from a strain of curvularia inaequalis. | xylanase, beta-glucosidase, beta-xylosidase, endoglucanase and polygalacturonase production from curvularia inaequalis was carried out by means of solid-state and submerged fermentation using different carbon sources. beta-glucosidase, beta-xylosidase, polygalacturonase and xylanase produced by the microorganisms were characterized. beta-glucosidase presented optimum activity at ph 5.5 whereas xylanase, polygalacturonase and beta-xylosidase activities were optimal at ph 5.0. maximal activity of ... | 2001 | 11830941 |
| purification and general properties of pectin methyl esterase from curvularia inaequalis nrrl 13884 in solid state culture using orange peels as an inducer. | pectin methyl esterase (pme) [e.c.3. 1.1.11] production by curvularia inaequalis (shear) boedijn nrrl 13884 was investigated using solid-state culture. the highest level of extracellular pectin methyl esterase was detected with orange peels as an inducing substrate and as a sole carbon source. the enzyme was partially purified using sephadex g-100 and deae-cellulose column chromatography. it was purified about 40 fold with optimum activity at ph 4.4 and 45 degrees c. the enzyme was activated by ... | 2002 | 12588098 |
| chlorination and cleavage of lignin structures by fungal chloroperoxidases. | two fungal chloroperoxidases (cpos), the heme enzyme from caldariomyces fumago and the vanadium enzyme from curvularia inaequalis, chlorinated 1-(4-ethoxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-1,3-dihydroxypropane, a dimeric model compound that represents the major nonphenolic structure in lignin. both enzymes also cleaved this dimer to give 1-chloro-4-ethoxy-3-methoxybenzene and 1,2-dichloro-4-ethoxy-5-methoxybenzene, and they depolymerized a synthetic guaiacyl lignin. since fungal cpos occur i ... | 2003 | 12902304 |
| inhibition of vanadium chloroperoxidase from the fungus curvularia inaequalis by hydroxylamine, hydrazine and azide and inactivation by phosphate. | the first detailed inhibition study of recombinant vanadium chloroperoxidase (rvcpo) using hydroxylamine, hydrazine and azide has been carried out. hydroxylamine inhibits rvcpo both competitively and uncompetitively. the competitive inhibition constant k(ic) and the uncompetitive inhibition constant k(iu) see are 40 and 80 microm, respectively. the kinetic data suggest that rvcpo may form a hydroxylamido complex, hydroxylamine also seems to react with the peroxovanadate complex during turnover. ... | 2004 | 15041242 |
| effect of static magnetic field on growth and sporulation of some plant pathogenic fungi. | growth and sporulation of phytopathogenic microscopic fungi were studied under a static magnetic field. the applied flux densities were 0.1, 0.5, and 1 mt. the magnetic field decreased the growth of colonies by 10% using this flux density region. at 0.1 mt flux density, the deviations are significant, p =.001, while in other cases the deviations generally are not significant. at the same time, the number of the developed conidia of alternaria alternata and curvularia inaequalis increased by 68-1 ... | 2004 | 15114642 |
| peritonitis due to curvularia inaequalis in an elderly patient undergoing peritoneal dialysis and a review of six cases of peritonitis associated with other curvularia spp. | fungal peritonitis due to curvularia species in patients undergoing peritoneal dialysis is a very rare problem. we report a case of peritonitis caused by curvularia inaequalis. this is the first report in the english literature of this species causing human infection. we also review the six previously reported cases of continuous ambulatory peritoneal dialysis peritonitis caused by other curvularia species. | 2005 | 16082004 |
| laboratory-evolved vanadium chloroperoxidase exhibits 100-fold higher halogenating activity at alkaline ph: catalytic effects from first and second coordination sphere mutations. | directed evolution was performed on vanadium chloroperoxidase from the fungus curvularia inaequalis to increase its brominating activity at a mildly alkaline ph for industrial and synthetic applications and to further understand its mechanism. after successful expression of the enzyme in escherichia coli, two rounds of screening and selection, saturation mutagenesis of a "hot spot," and rational recombination, a triple mutant (p395d/l241v/t343a) was obtained that showed a 100-fold increase in ac ... | 2006 | 16455658 |
| structure and function of vanadium haloperoxidases. | a quantum mechanics/molecular mechanics study of the resting state of the vanadium dependent chloroperoxidase from fungi curvularia inaequalis and of the early intermediates of the halide oxidation is reported. the investigation of different protonation states indicates that the enzyme likely consists of an anionic h2vo4- vanadate moiety where one hydroxo group is in axial position. the calculations suggest that the hydrogen peroxide binding may not involve an initial protonation of the vanadate ... | 2006 | 16494433 |
| chlorination of lignin by ubiquitous fungi has a likely role in global organochlorine production. | soils and decayed plant litter contain significant quantities of chlorinated aromatic polymers that have a natural but largely unknown origin. we used cupric oxide ligninolysis coupled with gas chromatography/mass spectrometry to show that curvularia inaequalis, a widely distributed litter ascomycete, chlorinated the aromatic rings of lignin in wood that it was degrading. in aspen wood decayed for 24 weeks, two chlorolignin fragments, 5-chlorovanillin and 2-chlorosyringaldehyde, were each found ... | 2007 | 17360449 |
| crystal structure of a trapped phosphate intermediate in vanadium apochloroperoxidase catalyzing a dephosphorylation reaction. | the crystal structure of the apo form of vanadium chloroperoxidase from curvularia inaequalis reacted with para-nitrophenylphosphate was determined at a resolution of 1.5 a. the aim of this study was to solve structural details of the dephosphorylation reaction catalyzed by this enzyme. since the chloroperoxidase is functionally and evolutionary related to several acid phosphatases including human glucose-6-phosphatase and a group of membrane-bound lipid phosphatases, the structure sheds light o ... | 2008 | 18163651 |
| eosinophilic fungal rhinosinusitis due to the unusual pathogen curvularia inaequalis. | among fungi, curvularia inaequalis is a rare pathogen. we report the first case of non-invasive fungal rhinosinusitis caused by this species. endoscopic sinus surgery revealed massive polyposis and the presence of viscous eosinophilic mucus that allowed the growth of the fungus. we diagnosed eosinophilic fungal rhinosinusitis based on the histological findings of fungal hyphae in association with degranulating eosinophils in the sinus mucus. after polypectomy and clearance of the affected sinuse ... | 2010 | 19207840 |
| vanadium k-edge xas studies on the native and peroxo-forms of vanadium chloroperoxidase from curvularia inaequalis. | vanadium k-edge x-ray absorption spectra have been recorded for the native and peroxo-forms of vanadium chloroperoxidase from curvularia inaequalis at ph 6.0. the extended x-ray absorption fine structure (exafs) regions provide a refinement of previously reported crystallographic data; one short v=o bond (1.54a) is present in both forms. for the native enzyme, the vanadium is coordinated to two other oxygen atoms at 1.69a, another oxygen atom at 1.93a and the nitrogen of an imidazole group at 2. ... | 2010 | 20346515 |
| superficial mycosis of the breast caused by curvularia inaequalis. | | 2010 | 20627856 |
| in vitro degradation of the moss hylocomium splendens by three pleosporalean fungi. | three darkly pigmented species of conidial fungi of the family pleosporaceae isolated from plants colonizing the saskatchewan glacier forefield were examined for potential roles in the degradation of moss gametophytes. curvularia inaequalis and ulocladium atrum isolated from bryophytes ditrichum flexicaule and tortella tortuosa , respectively, and chalastospora gossypii from saxifraga oppositifolia were inoculated onto autoclaved gametophytes of the moss hylocomium splendens. all three species o ... | 2011 | 21539496 |