PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “MUTASES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed1994

Crystallization and preliminary structural studies of a chorismate mutase catalytic antibody complexed with a transition state analog.

The Fab' fragment of a catalytic antibody with chorismate mutase activity has been crystallized as a complex with the transition-state analog hapten. The complex was crystallized by the vapor diffusion method using ammonium sulfate as the precipitant. The crystals belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions a = 37.1 A, b = 63.3 A, c = 178.5 A, and there is one Fab' molecule per asymmetric unit. The crystals diffract X-rays to at least 3.0 A and are suitable for X-ray crystallographic studies.

Animals↗
PubMed2001

A new stroke marker as detected by serum phosphoglycerate mutase B-type isozyme.

The diagnostic significance of phosphoglycerate mutase (PGM) B-type isozyme activity capable of being inducible under hypoxia at the gene level as a serum marker for cerebral stroke was investigated. The normal level (mean +/- 2 SD) in human serum was determined to be 38 +/- 18 units/L. Within 2 h after the onset of cerebral stroke (n = 65), B-type isozyme activity was elevated to 68 +/- 36 units/L, and retained to be higher level until 1-3 days. Serum B-type isozyme activities of 52 survival cases and 13 dead cases, being judged at the period of 1-2 months after the onset, were retrospectively compared; B-type isozyme activity that had been measured within 24 h after the onset was significantly higher (81 +/- 42 units/L) for the dead cases than for survival cases (57 +/- 27 units/L) with P < 0.05. These results suggest that serum PGM B-type isozyme has the potential as a novel marker for diagnosis of cerebral stroke and its severity.

Adolescent↗
PubMed1994

The crystallization and preliminary X-ray analysis of allosteric chorismate mutase.

An allosteric chorismate mutase, the Thr226-->Ile mutant, from the yeast Saccharomyces cerevisiae has been crystallized in space group P6(1)(P6(5)) using the hanging drop vapour diffusion method at room temperature. The cell dimensions are a = b = 95.8 A, c = 157.9 A, alpha = beta = 90 degrees, gamma = 120 degrees. It contains a dimer in the crystallographic asymmetric unit. The crystal diffracts to 2.2 A resolution. A native data set has been collected to 82% completeness at this resolution.

Allosteric Regulation↗
PubMed1999

Sulphate ions observed in the 2.12 A structure of a new crystal form of S. cerevisiae phosphoglycerate mutase provide insights into understanding the catalytic mechanism.

The structure of a new crystal form of Saccharomyces cerevisiae phosphoglycerate mutase has been solved and refined to 2.12 A with working and free R-factors of 19.7 and 22.9 %, respectively. Higher-resolution data and greater non-crystallographic symmetry have produced a more accurate protein structure than previously. Prominent among the differences from the previous structure is the presence of two sulphate ions within each active site cleft. The separation of the sulphates suggests that they may occupy the same sites as phospho groups of the bisphosphate ligands of the enzyme. Plausible binding modes for 2,3-bisphosphoglycerate and 1, 3-bisphosphoglycerate are thereby suggested. These results support previous conclusions from mutant studies, highlight interesting new targets for mutagenesis and suggest a possible mechanism of enzyme phosphorylation.

2,3-Diphosphoglycerate↗
PubMed2001

Solution structure and dynamics of an open beta-sheet, glycolytic enzyme, monomeric 23.7 kDa phosphoglycerate mutase from Schizosaccharomyces pombe.

The structure and backbone dynamics of a double labelled (15N,13C) monomeric, 23.7 kD phosphoglycerate mutase (PGAM) from Schizosaccharomyces pombe have been investigated in solution using NMR spectroscopy. A set of 3125 NOE-derived distance restraints, 148 restraints representing inferred hydrogen bonds and 149 values of (3)J(HNHalpha) were used in the structure calculation. The mean rmsd from the average structure for all backbone atoms from residues 6-205 in the best 21 calculated structures was 0.59 A. The core of the enzyme includes an open, twisted, six-stranded beta-sheet flanked by four alpha-helices and a short 3(10)-helix. An additional smaller domain contains two short antiparallel beta-strands and a further pair of alpha-helices. The C(alpha) atoms of the S. pombe PGAM may be superimposed on their equivalents in one of the four identical subunits of Saccharomyces cerevisiae PGAM with an rmsd of 1.34 A (0.92 A if only the beta-sheet is considered). Small differences between the two structures are attributable partly to the deletion in the S. pombe sequence of a 25 residue loop involved in stabilising the S. cerevisiae tetramer. Analysis of 15N relaxation parameters indicates that PGAM tumbles isotropically with a rotational correlation time of 8.7 ns and displays a range of dynamic features. Of 178 residues analysed, only 77 could be fitted without invoking terms for fast internal motion or chemical exchange, and out of the remainder, 77 required a chemical exchange term. Significantly, 46 of the slowly exchanging (milli- to microsecond) residues lie in helices, and these account for two-thirds of all analysed helix residues. On the contrary, only one beta-sheet residue required an exchange term. In contrast to other analyses of backbone dynamics reported previously, residues in slow exchange appeared to correlate with architectural features of the enzyme rather than congregating close to ligand binding sites.

Amino Acid Substitution↗
PubMed1999

Structural studies on a 2,3-diphosphoglycerate independent phosphoglycerate mutase from Bacillus stearothermophilus.

Phosphoglycerate mutase (PGM), an important enzyme in the glycolytic pathway, catalyzes the transfer of a phosphate group between the 2 and the 3 positions of glyceric acid. The gene coding for the 2, 3-diphosphoglycerate independent monomeric PGM from Bacillus stearothermophilus (57 kDa), whose activity is extremely pH sensitive and has an absolute and specific requirement for Mn2+, has been cloned and the enzyme overexpressed and purified to homogeneity. Circular dichroism studies showed at most only small secondary structure changes in the enzyme upon binding to Mn2+ or its 3-phosphoglycerate substrate, but thermal unfolding analyses revealed that Mn2+ but not 3-phosphoglycerate caused a large increase in the enzyme's stability. Diffraction-quality crystals of the enzyme were obtained at neutral pH in the presence of 3-phosphoglyceric acid with ammonium sulfate as the precipitating agent; these crystals diffract X rays to beyond 2.5-A resolution and belong to the orthorhombic space group C2221 with unit cell dimensions, a = 58.42, b = 206.08, c = 124.87 A, and alpha = beta = gamma = 90.0 degrees. The selenomethionyl version of the B. stearothermophilus protein has also been overexpressed, purified, and crystallized. Employing these crystals, the determination of the three-dimensional structure of this PGM by the multiwavelength anomalous dispersion method is in progress.

2,3-Diphosphoglycerate↗
PubMed1996

Lily cofactor-independent phosphoglycerate mutase: purification, partial sequencing, and immunolocalization.

A cofactor-independent phosphoglycerate mutase (PGAM-i) was isolated to homogeneity from monocotyledonous Lilium longiflorum Thunb. Two-dimensional (2D) polyacrylamide gel electrophoresis resolved three PGAM-i forms. This enzyme was originally identified by cross-reactivity to antibodies affinity-purified from 2D gels using human vitronectin (VN). Antibody produced against a denatured protein spot from a 2D gel did not recognize VN protein, but partial protein and DNA sequencing showed similarity of the former protein to maize PGAM-i. Immunoblots from roots, styles, leaves, and anthers showed the presence of PGAM-i in all tissues examined; it was isolated predominantly from the soluble cell fraction, with some present in the insoluble cell fraction. Immunoelectron microscopy demonstrated its localization in the cytoplasm and plastids in root cells near the apical meristem. In addition, immunogold labeling detected signals from the nucleus. The immunohistochemical localization of the enzyme in the nucleus, as well as in the cytosol and plastids, indicates that lily PGAM-i might have multiple functions in the cell.

Amino Acid Sequence↗
PubMed1990

In situ mapping of the muscle-specific form of phosphoglycerate mutase gene to human chromosome 7p12-7p13.

A 2.3-kb-long probe derived from the 5' flanking region, the first exon and part of the first intron of the human muscle-specific phosphoglycerate mutase gene (PGAM-M) (EC 5.4.2.1) was used to map the gene by "in situ" chromosomal hybridization. The structural gene for PGAM-M was assigned to chromosome 7p12-7p13; a single hybridization peak indicated that there is a single gene for this isozyme of PGAM, and confirmed results obtained by Southern blot hybridization.

Bisphosphoglycerate Mutase↗
PubMed1992

Phenotype of disease in three patients with identical mutations in methylmalonyl CoA mutase.

We have previously identified a mutation in the gene for methylmalonyl CoA mutase in a patient with the mut- phenotype of methylmalonic aciduria. This mutation (G717V) interferes with the binding of the deoxyadenosylcobalamin cofactor to the apoenzyme producing a mutant holoenzyme that is defective, but not completely inactive, in vitro. This report describes the clinical phenotype associated with this mutation in the original patient and two additional patients who are homozygous for this allele. All three patients presented in the first years of life with multiple episodes of life-threatening organic acidosis and hyperammonemia. None had evidence of disease in the perinatal period, and all three have low-normal intelligence. These three children exhibit a distinctive phenotype of disease that is intermediate between the fulminant and benign forms of methylmalonic aciduria. These data suggest that this phenotype is the specific consequence of the G717V mutation, and that the degree of residual enzyme activity associated with the G717V mutation is close to the threshold required in vivo for maintaining metabolic homeostasis.

Acidosis↗
PubMed1991

Sequence and localization of the gene encoding yeast phosphoglycerate mutase.

In this study we report on the complete nucleotide sequence of the yeast phosphoglycerate mutase gene (GPM1) and its essential 5' and 3' non-coding regions. The transcriptional start points were determined by S1-mapping and sequencing of a cDNA clone. Several sequences identified as important for transcriptional regulation in yeast promoters are present upstream of the transcription start point. 3' to the coding region we sequenced a composite repetitive element which, apparently, originated from a recombination between a delta- and a tau-element. Finally, we mapped the GPM1 gene 13 cM distal to fas1 on chromosome XI.

Amino Acid Sequence↗
PubMed1986

Molecular cloning and characterization of ARO7-OSM2, a single yeast gene necessary for chorismate mutase activity and growth in hypertonic medium.

The chorismate mutase structural gene, ARO7, which is necessary for both phenylalanine and tyrosine biosynthesis was cloned by complementation in yeast. Genetic analysis showed that ARO7 was identical to a gene necessary for growth in hypertonic medium, OSM2, which mapped nearby. After restriction mapping and subcloning of the plasmid, the cloned gene was used to detect mRNA levels in several growth conditions. Enzyme activities were measured in various genotypes. At our level of detection ARO7-OSM2 is a low level constitutively expressed gene.

Chorismate Mutase↗
PubMed1994

Muscle phosphoglycerate mutase (PGAM) deficiency in the first Caucasian patient: biochemistry, muscle culture and 31P-MR spectroscopy.

Muscle phosphoglycerate mutase (PGAM) deficiency has been so far identified in only six patients, five of these being African Americans. We report the results of clinical, morphological, biochemical, muscle culture and 31P-MR spectroscopy studies in the first Caucasian patient with muscle PGAM deficiency. A 23-year-old man had a 10-year history of cramps after physical exertion with one episode of pigmenturia. Neurological examination and EMG study were normal. ECG and echocardiography revealed hypertrophy of the interventricular septum and slight dilation of the left chambers of the heart. Muscle biopsy revealed increased glycogen content and some accumulation of mitochondria. Muscle PGAM activity was markedly decreased (6.5% and 9.7% of control value in two different biopsies). Citrate synthase and other mitochondrial respiratory chain enzyme activities were much higher than normal. In contrast to the marked decrease of PGAM activity observed in muscle biopsy, total enzyme activity in the patient's aneural muscle culture was normal, being represented exclusively by BB isoenzyme. The deficiency of PGAM-MM isoenzyme was reproduced in the patient's innervated muscle culture. Muscle 31P-MR spectroscopy showed accumulation of phosphomonoesters only on fast "glycolytic" exercise. On "aerobic" exercise, Vmax, calculated from the work-energy cost transfer function, showed an increase consistent with the morphological and biochemical evidence of mitochondrial proliferation. This might represent a sort of compensatory aerobic effort in an attempt to restore muscle power.

Adult↗
PubMed1987

Bisphosphoglycerate mutase and pyruvate kinase activities during maturation of reticulocytes and ageing of erythrocytes.

An increase in bisphosphoglycerate mutase (BPGM) and a decrease in pyruvate kinase (PK), i.e. a decrease in PK/BPGM ratio, was observed in red cell populations from anemic rats containing 95% down to 3% reticulocytes in blood. Such a ratio has been used to study the fractionation of recticulocytes, according to their degree of maturation, after counter-current distribution of those cell populations in dextranpoly (ethylene glycol) two-phase systems. When applying this procedure to the fractionation according to age of erythrocytes from normal rats, the decrease of PK with cellular age was observed without a significant variation in BPGM activity.

Anemia↗
PubMed1983

Distinction between cofactor-dependent and -independent phosphoglycerate mutases by chromatography on Cibacron Blue-Sepharose.

The binding of phosphoglycerate mutases from a variety of sources to Cibacron Blue-Sepharose has been examined. Those enzymes which are dependent on 2,3-bisphosphoglycerate (BPG) for activity bind to the immobilized dye and can be eluted by BPG. Those enzymes which are independent of BPG do not bind to the immobilized dye. The possible structural significance of this distinction is discussed.

2,3-Diphosphoglycerate↗
PubMed1992

Propionate metabolism in cultured human cells after overexpression of recombinant methylmalonyl CoA mutase: implications for somatic gene therapy.

Strategies for somatic gene therapy must consider the metabolic consequences of expressing the recombinant gene product in addition to methods for gene transfer and expression. We describe studies of propionate metabolism in cultured cells transfected with methylmalonyl CoA mutase (MCM), the enzyme deficient in mut methylmalonic acidemia. Transfection of MCM into mut fibroblasts restores propionate metabolism to normal levels in a dose-dependent manner. Overexpression of MCM, or the addition of excess propionate, carnitine, or cobalamin, does not increase propionate metabolism in normal human fibroblasts, lymphoblasts, or hepatoma cells, although hepatic cells exhibit > 10-fold higher levels of propionate metabolism. Significantly, the restoration of propionate metabolism in mut fibroblasts is disproportionately greater than the efficiency of transfection, suggesting the presence of a cooperative phenomenon between cells. Intercellular participation in propionate metabolism is evident in cocultures of MCM-deficient and propionyl CoA carboxylase-deficient cells. We conclude that the liver is the preferred target for gene therapy of MCM deficiency because of its greater capacity for propionate metabolism and that cooperation between cells could enhance the biological effect of a subpopulation of cells transformed with recombinant MCM.

Amino Acid Metabolism, Inborn Errors↗
PubMed2006

Cofactor-independent phosphoglycerate mutase is an essential gene in procyclic form Trypanosoma brucei.

Glycolysis and gluconeogenesis are, in part, driven by the interconversion of 3- and 2-phosphoglycerate (3-PG and 2-PG) which is performed by phosphoglycerate mutases (PGAMs) which can be cofactor dependant (dPGAM) or cofactor independent (iPGAM). The African trypanosome, Trypanosoma brucei, possesses the iPGAM form which is thought to play an important role in glycolysis. Here, we report on the use of RNA interference to down-regulate the T. brucei iPGAM in procyclic form T. brucei and evaluation of the resulting phenotype. We first demonstrated biochemically that depletion of the steady state levels of iPGM mRNA correlates with a marked reduction of enzyme activity. We further show that iPGAM is required for cell growth in procyclic T. brucei.

Animals↗