Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.1 (aspartate aminotransferase)
 21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Guanine deaminase catalyses the conversion of guanine to xanthine and ammonia, thereby irreversibly removing the guanine base from the pool of guanine-containing metabolites. We have identified five alleles at the mouse guanine deaminase locus by cDNA sequencing. These alleles were defined by single-nucleotide polymorphisms at a total of 19 positions. For each allele the representative strains are as follows: Gda(a), C57BL/6J and DBA/2J; Gda(b), A/J; Gda(c), MOLF/Ei; Gda(d), CAST/Ei; and Gda(e), SPRET-1. The only codon change resulting in an amino acid substitution was found at nucleotide 523, where GAT was replaced by AAT in Mus spretus resulting in the deduced substitution of Asp-174 by Asn. The single-nucleotide difference between the a and b alleles was also typed by allele-specific oligonucleotide amplification for 17 common strains of Mus musculus susbp. musculus. By typing the AxB and BxA recombinant inbred (RI) strain sets, Gda was mapped to mouse chromosome 19, a region syntenic with human chromosome 9q11-q22.
 ...
PMID:cDNA sequence of five mouse guanine deaminase (Gda) alleles and mapping to mouse chromosome 19. 1196 25

Hemoglobin (Hb) Korle-Bu (beta73; Asp-Asn) is the most frequent of the rare beta-chain variants in the population of West Africa whereas Hb E (beta26; Glu-Lys) is common among the Southeast Asian population. We report a hitherto undescribed condition in which these two beta-chain variants co-segregate. The proband was a 19-year-old Thai pregnant woman in her second trimester of pregnancy who visited our thalassemia screening unit. Cellulose acetate electrophoresis and high-performance liquid chromatography (HPLC) analysis of Hb detected one abnormal Hb in addition to the Hb E. Analysis of DNA sequences revealed a GAT-AAT mutation at codon 73 in trans to a GAG-AAG mutation at codon 26 of the beta-globin gene. Polymerase chain reaction (PCR) analysis of the alpha-globin gene cluster of the patient detected a 3.7-kb deletional alpha-thalassemia 2. Family study identified that her mother had the same genotype and her father was a simple Hb E carrier. The hematological data of these unusual cases of hemoglobinopathy are presented and compared with a simple heterozygote for Hb Korle-Bu found in another unrelated Thai family. beta-Globin gene haplotype linked to the Thai beta(Korle-Bu) and a simple DNA assay based on allele-specific PCR for rapid diagnosis of Hb Korle-Bu are also described.
 ...
PMID:Compound heterozygosity for Hb Korle-Bu (beta(73); Asp-Asn) and Hb E (beta(26); Glu-Lys) with a 3.7-kb deletional alpha-thalassemia in Thai patients. 1218 10

Acephala applanata gen. et sp. nov. is described. A. applanata is a dark-septate endophyte (DSE) of conifer roots and belongs to the Phialocephala fortinii species complex. Several genetic markers, including isozymes, inter-simple-sequence-repeat (ISSR) fingerprints, single-copy restriction fragment length polymorphisms (RFLP) and sequences of the internal transcribed spacers (ITS), let us unambiguously separate isolates of A. applanata from isolates of P. fortinii s.l. and other dark-septate endophytes. Alleles at four RFLP loci and two fixed nucleotides in the ITS region were diagnostic for A. applanata. One of the fixed nucleotides resulted in the addition of an Afa I restriction site. PCR amplification with primers prITS4 and the newly developed primer PF-ITS_F (ACT CTG AAT GTT AGT GAT GTC TGA GT) and restriction digestion with Afa I yielded three fragments (203 bp, 117 bp, 56 bp) in A. applanata but only two (260 bp and 117 bp) in P. fortinii s.l. Population differentiation (GST) between A. applanata and other cryptic species of P fortinii was pronounced, and the index of association (IA) did not deviate significantly from zero, showing that recombination occurs or had occurred in A. applanata. Although isolates of A. applanata never were observed to sporulate, it can be distinguished morphologically from P fortinii s.l. by the scarcity of aerial mycelium, significantly slower growth and denser mycelium on cellophane overlaid on water agar. These phenotypic characteristics, combined with diagnostic RFLP alleles and/or PCR-RFLP of the ITS fragment with the fixed Afa I restriction site, unequivocally allow identification of A. applanata.
 ...
PMID:Molecular and phenotypic description of the widespread root symbiont Acephala applanata gen. et sp. nov., formerly known as dark-septate endophyte type 1. 1639 52

The molecular basis of ovarian cancer development has not been fully elucidated. In this study, genetic alterations in ovarian cancer were identified by arbitrarily primed polymerase chain reaction (AP-PCR). A gene in DNA fingerprinting, amplified from primer AE11, was cloned, sequenced, and identified by comparison with known genes in the genome database. Gene amplification in chromosome 10q24.3 was identified and measured by real-time PCR. Three out of 20 cases harbored this gene amplification. This amplified region was identified as IVS-4 of the glutathione-S-transferase Omega 2 (GSTO2) gene. Therefore, the mutations in all 6 exons of the GSTO2 gene were determined. The A to G transition at codon 142 in exon 4 (AAT to GAT, N142D) was observed. The frequency of GSTO2 gene polymorphism was analyzed in 20 ovarian cancers, compared with 41 normal individuals. The gene frequencies of D142 and N142 allele in ovarian cancer cases were 0.3 and 0.7, whereas in normal females, they were 0.2 and 0.8, respectively. The odds ratio of D142 allele in ovarian cancer was 1.73 (95% CI = 0.51-5.89), indicating that this GSTO2 gene polymorphism may be associated with the risk of ovarian cancer.
 ...
PMID:Genetic alterations in chromosome 10q24.3 and glutathione S-transferase omega 2 gene polymorphism in ovarian cancer. 1676 26

Proteomic analyses of the beta subunit of the plastid ATP synthase of barley (Hordeum vulgare L.) revealed that mature protein was not carboxy terminus processed and suggested the correction of the 274 codon (GAT to AAT) in the data bank that was confirmed by DNA sequencing. Six isoforms of the ATP synthase beta subunit with pI ranging from 4.95 to 5.14 were resolved by two-dimensional electrophoresis (2-DE). Mass spectrometry analyses indicated that the six isoforms differ in their phosphorylation degree, which was confirmed by the disappearance of more acidic forms after incubation with the protein phosphatase calcineurin. Six Ser and/or Thr were detected as phosphorylated, among them the conserved Thr-179 that is also phosphorylated in the beta subunit of human mitochondria. The results are discussed in relation with the proposed regulation of the ATP synthase by phosphorylation and 14-3-3 proteins.
 ...
PMID:Multiple phosphorylation sites in the beta subunit of thylakoid ATP synthase. 1683 3

In the present study, Brucella melitensis biovar Abortus 2308 and Brucella abortus 3196 biotype 5 reference strains, which are susceptible to fluoroquinolones, became in vitro-resistant to fluoroquinolones by culture in trypticase soy agar. The quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes of the two reference strains were analysed by polymerase chain reaction sequencing analysis to obtain the wild-type sequence. These sequences were then compared with the corresponding sequences of four in vitro-selected fluoroquinolone-resistant mutants to characterise mutations associated with resistance. Sequencing of the ofloxacin-selected resistant mutant 2308 revealed a transition of GAT to AAT (corresponding to position 87 of Escherichia coli gyrA), leading to substitution of Asp91-->Asn, whilst at the same position the ciprofloxacin-selected resistant mutant 2308 revealed a transition of GAT to TAT (corresponding to the same position of E. coli as above), leading to substitution of Asp91-->Tyr. The ofloxacin-selected resistant mutant 3196 had a transition of GCT to GTT, generating an amino acid change of Ala87-->Val. Amino acid changes were detected in the portion of the Brucella gyrA gene (Ala71 to Gln110) corresponding to the E. coli gyrA QRDR region (Ala67 to Gln110). Amino acid changes were also detected in Ser83, corresponding to the region where fluoroquinolone-associated amino acid changes are most commonly found in other bacterial species.
 ...
PMID:In vitro-selected resistance to fluoroquinolones in two Brucella strains associated with mutational changes in gyrA. 1858

Nine clones of non-pathogenic streptococci were isolated from the pharynges of seven healthy subjects, and grown on sheep blood agar plates with a hemolysis or gamma hemolysis, then cultured in LB broth for 16 hrs. Purified streptolysin O (SLO) purchased from Sigma Chemical Co. (Sigma-SLO), SLO antigen as a latex agglutination reagent from A company (A-SLO) and supernatants from four culture media were electrophoresed on 12% SDS-polyacrylamide gel and transferred to PVDF membranes. Immunological analyses of antibodies against SLO in healthy sera and proteins in culture medium demonstrated that healthy sera contained an antibody recognizing Sigma-SLO, A-SLO and a protein of the same size as SLO (SLO-like protein) in culture medium. These findings suggest that healthy subjects develop an antibody directed against SLO-like protein produced by non-pathogenic streptococci, and that this antibody cross-reacts with Sigma-SLO and A-SLO. Using DNA from Streptococcus pyogenes and non-pathogenic streptococci, the SLO gene and SLO-like protein gene were analyzed by direct sequencing with oligonucleotide primers designed to cover no. 74 to approximately 1900 of the SLO gene. There were three different bases resulting in amino acid substitution between the SLO gene and SLO-like protein gene, namely 101Lys (AAA) of SLO to Asn (AAT), 175Met (ATG) to Arg (AGG) and 185Asp (GAT) to Asn (AAT). Remaining 560 residues of 563 amino acids constituting SLO-like protein were homologous to SLO. Non-pathogenic streptococci on the pharynges of healthy subjects produce an SLO-like protein composed of amino acids similar to those of SLO, which induces an antibody against this SLO-like protein in serum. It is likely that an antibody against SLO-like protein in healthy sera cross-reacts with SLO and causes a pseudo-positive reaction on ASO measurement by the latex agglutination method using SLO antigen.
 ...
PMID:[Structural homology between streptolysin O (SLO) produced by streptococcus pyogenes and SLO-like protein produced by non-pathogenic streptococci and cross-reactivity of antibody against SLO-like protein to SLO]. 1880 Jun 23

Monitoring of the susceptibility of Mycoplasma bovis field isolates to antibiotics is important for the appropriate choice of treatment. However, in vitro susceptibility testing of mycoplasmas is technically demanding and time-consuming, especially for clinical isolates, and is rarely performed in mycoplasma diagnostic laboratories. Thus, the development of methods allowing rapid real-time detection of resistant strains of M. bovis in clinical samples is a high priority for successful treatment. In this study, a novel TaqMan single-nucleotide-polymorphism (SNP) real-time PCR assay, which enables the rapid identification of M. bovis strains with different susceptibilities to fluoroquinolones, was developed and evaluated. The TaqMan SNP real-time PCR assay is based on the amplification of a 97-bp fragment of the parC quinolone resistance-determining region (QRDR) and allows the specific detection of four possible genotypes: GAC or GAT (susceptible to fluoroquinolones) and AAC or AAT (resistant to fluoroquinolones). Four TaqMan minor groove binder (MGB) probes identifying 1-base mismatches were designed and applied in a dual-probe assay with two reaction tubes. The TaqMan SNP real-time PCRs developed are highly specific for M. bovis, with a detection limit of 5 fg/microl (about 5 M. bovis genomes). In addition, all four SNP real-time PCR tests have almost the same efficiency (97.7% [GAC], 94% [AAC], 99.99% [GAT], and 98% [AAT]). Taken together, the data suggest that this SNP real-time PCR assay has potential as a routine diagnostic test for the detection of decreased susceptibility of M. bovis to fluoroquinolones.
 ...
PMID:Development and evaluation of a novel single-nucleotide-polymorphism real-time PCR assay for rapid detection of fluoroquinolone-resistant Mycoplasma bovis. 2053 3

Patients infected with bacteria producing extendedspectrum beta-lactamases (ESBL) are at higher risk of mortality and morbidity. Several mutations in genes encoding SHV, tem and CTX-M beta-lactamases have been associated with ESBL activity. This paper describes a new SHV mutation in ESBL-producing strains of Klebsiella pneumoniae isolated in Kuwait. The study included 13 K. penumoniae strains isolated from patients admitted to the Amiri hospital of Kuwait. The production of ESBL in all strains was confirmed by Vitek system and E-test. All the ESBL genes were amplified by PCR and examined by DNA sequencing. All these ESBL-positive isolates were resistant to ceftazidime and cefotaxime. DNA sequencing revealed an A815G point mutation in the bla (SHV )gene causing an asparagine (AAT) to aspartic acid (GAT) mutation at position 253 of the enzyme. This new mutation was assigned the unique number SHV-112, and the Genebank accession number EU477409. This study reports a new mutation in the SHV gene in K. pneumoniae with ESBL capability. There could be other mutations still to be found in ESBL genes of K. pneumoniae in Kuwait and probably in other middle eastern countries, and researchers in the region should make use of molecular techniques to look for more novel mutations in ESBL-producing strains of K. pneumoniae.
 ...
PMID:Retrospective study of an outbreak in a Kuwaiti hospital of multidrug-resistant Klebsiella pneumoniae possessing the new SHV-112 extended-spectrum beta-lactamase. 2112 57

A novel peptide nucleic acid (PNA)-based array was developed for use in ante-mortem antigenic typing discrimination in dogs with canine parvovirus (CPV). Cyclic benzothiazole-2-sulfonyl PNA monomers were synthesized that recognized GTA (CPV-2) and TAT (CPV-2a, -2b and -2c) at the nt 913-915 positions, and AAT (CPV-2 and CPV-2a), GAT (CPV-2b), and GAA (CPV-2c) at the nt 1276-1278 positions of the VP2 gene. The detection limits for aa 305 and aa 426 of the VP2 proteins belonging to the four CPV antigenic types were determined optically to be 40-2000 DNA copies, and the optimal cut-off fluorescence signaling value was fixed at 5000. The PNA array described here was developed from 135 field dog fecal specimens and had 89.8% (62/69) sensitivity and 90.4% (66/73) specificity compared with a real-time PCR using the TaqMan assay, a gold standard method. This CPV PNA array could be used together with MGB probe assays as an attractive novel tool for ante-mortem antigenic typing discrimination.
 ...
PMID:Peptide nucleic acid-based (PNA) array for the antigenic discrimination of canine parvovirus. 2176 14


<< Previous 1 2 3 4 5 Next >>