Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 21
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract 5-Carboxymethyl-2-hydroxymuconic semialdehyde (CHMS) dehydrogenase from Escherichia coli C and Klebsiella pneumoniae M5a1 have been purified and some of their properties studied. The apparent Km values for NAD and CHMS were 11.7 ± 1.5 μM and 5.2 ± 1.9 μM. respectively, for the K. pneumoniae enzyme, and 19.5 ± 2.7 μM and 9.2 ± 1.4 μM, respectively, for the E. coli enzyme. Both enzymes were optimally active at pH 7.5 in sodium phosphate buffer. They had subunit molecular weights of 52 000 (± 1000) and the native enzymes appeared to be dimers of identical subunits. The first 20 residues of their N-terminal amino acid sequences were 90% homologous. A degenerate oligonucleotide probe constructed to a six amino acid sequence common to both enzymes gave strong hybridization with DNA from E. coli strains B and W as well as with E. coli C and K. pneumoniae but little or no hybridization to DNA from E. coli K12 or Pseudomonas putida.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 133 (1995), S. 0 
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Arthrobacter globiformis amine oxidase produced by Escherichia coli cells grown in copper-depleted media was reported to undergo activation due to formation of its topaquinone cofactor in a copper-dependent autocatalytic reaction. Likewise, a mutated E. coli amine oxidase located in the cytoplasm was reported to form topaquinone autocatalytically in an EDTA-sensitive reaction. Here we show unequivocally that formation of an amine oxidase lacking topaquinone is primarily a consequence of the location of the enzyme in the cytoplasm rather than the level of copper in the growth medium. For E. coli, insertion of copper into apoamine oxidase and subsequent topaquinone formation occur after export of the apoenzyme into the periplasm.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 52 (1988), S. 0 
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract A cloned gene specifying the 2-oxo-hept-3-ene-1,7-dioate (OHED) hydratase of Escherichia coli C was used to produce large amounts of the hydratase enzyme. The enzyme was purified to homogeneity by a simple two-step procedure and some of its properties investigated. The first 34 residues at the amino terminus were sequenced and a mixture of oligonucleotides corresponding to the first six amino acid residues was constructed. This mixture was used as a probe to look for sequence homology in DNA obtained from various related organisms that had OHED hydratase activity. Strong hybridization was seen for E. coli strains B and C but E. coli strain W and Klebsiella pneumoniae M5a1 showed no detectable hybridization.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 36 (1986), S. 0 
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Single-gene mutants of Escherichia coli defective in aerobactin biosynthesis were incubated under non-growing conditions for 2 h with radiolabelled lysine. Analysis of the intermediates produced suggested that acetylation of lysine may be the first step in aerobactin production.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 52 (1988), S. 0 
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Klebsiella pneumoniae M5a1 grows readily on two compounds, 4-hydroxyphenylacetate and 4-aminobutyrate, whose catabolism produces succinic semialdehyde. A single succinic semialdehyde dehydrogenase was detected, native molecular weight 52000, that has NAD as the preferred cofactor and is induced by succinic semialdehyde functions in the oxidation of succinic semialdehyde during growth on both 4-hydroxyphenyl-acetate and 4-aminobutyrate. This contrasts with the situation for Escherichia coli and Pseudomonas putida where two distinct forms of succinic semialdehyde dehydrogenase have been observed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 132 (1982), S. 270-275 
    ISSN: 1432-072X
    Keywords: Escherichia coli ; Succinate semialdehyde dehydrogenase ; Aromatic catabolism ; Hydroxyphenylacetate ; Genetic mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Escherichia coli mutants, unable to grown on 4-hydroxyphenylacetate, have been isolated and found to be defective in the NAD-dependent succinate semialdehyde dehydrogenase. When the mutants are grown with 4-aminobutyrate as sole nitrogen source an NAD-dependent succinate semialdehyde dehydrogenase seen in the parental strain is absent but, as in the parental strain, an NADP-dependent enzyme is induced. Growth of the mutants is inhibited by 4-hydroxyphenylacetate due to the accumulation of succinate semialdehyde. The mutants are more sensitive to inhibition by exogenous succinate semialdehyde than is the parental strain. Secondary mutants able to grow in the presence of 4-hydroxyphenylacetate but still unable to use it as sole carbon source were defective in early steps of 4-hydroxyphenylacetate catabolism and so did not form succinate semialdehyde from 4-hydroxyphenylacetate. The gene encoding the NAD-dependent succinate semialdehyde dehydrogenase of Escherichia coli K-12 was located at min 34.1 on the genetic map.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 118 (1978), S. 199-206 
    ISSN: 1432-072X
    Keywords: E. coli K-12 ; Galactonate ; 2-Oxo-3-deoxygalactonate ; Genetic mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract 1. Escherichia coli K-12 mutants unable to grow on d-galactonate have been isolated and found to be defective in either galactonate dehydratase, 2-oxo-3-deoxygalactonate 6-phosphate aldolase or devoid of both of these enzymes and of 2-oxo-3-deoxygalactonate kinase. 2. 2-Oxo-3-deoxygalactonate kinase and 2-oxo-3-deoxygalactonate 6-phosphate aldolase are still induced by galactonate in mutants lacking galactonate dehydratase, suggesting that galactonate rather than a catabolic product of galactonate is the inducer of the galactonate catabolic enzymes. Synthesis of the enzymes is subject to glucose catabolite repression. 3. Mutants defective in 2-oxo-3-deoxygalactonate 6-phosphate aldolase accumulate 2-oxo-3-deoxygalactonate 6-phosphate when exposed to galactonate and this compound causes general growth inhibition. 4. Secondary mutants that no longer show this inhibition fail to make 2-oxo-3-deoxygalactonate 6-phosphate due to additional defects in galactonate transport, galactonate dehydratase, 2-oxo-3-deoxygalactonate kinase or a putative promoter mutation that prevents formation of these enzymes. 5. A spontaneous mutant capable of growth on 2-oxo-3-deoxygalactonate has been isolated. It has two genetically distinct mutations. One permits constitutive formation of the galactonate catabolic enzymes and the other allows the uptake of 2-oxo-3-deoxygalactonate. Neither mutation on its own permitted growth on 2-oxo-3-deoxygalactonate. 6. Genes specifying the various galactonate catabolic enzymes have been located at min 81.7 on the E. coli K-12 linkage map and probably constitute an operon. The gene sequence in this region was shown to by: pyrE uhp dgo dnaA.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 154 (1990), S. 489-495 
    ISSN: 1432-072X
    Keywords: Klebsiella pneumoniae M5a1 ; 3-Hydroxybenzoate degradation ; Gentisate pathway ; 3-Hydroxybenzoate monooxygenase mutants ; Maleylpyruvate isomerase mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth of Klebsiella pneumoniae M5a1 on 3-hydroxybenzoate leads to the induction of 3-hydroxybenzoate monooxygenase, 2,5-dihydroxybenzoate dioxygenase, maleylpyruvate isomerase and fumarylpyruvate hydrolase. Growth in the presence of 2,5-dihydroxybenzoate also induces all of these enzymes including the 3-hydroxybenzoate monooxygenase which is not required for 2,5-dihydroxybenzoate catabolism. Mutants defective in 3-hydroxybenzoate monooxygenase fail to grow on 3-hydroxybenzoate but grow normally on 2,5-dihydroxybenzoate. Mutants lacking maleylpyruvate isomerase fail to grow on 3-hydroxybenzoate and 2,5-dihydroxybenzoate. Both kinds of mutants grow normally on 3,4-dihydroxybenzoate. Mutants defective in maleylpyruvate isomerase accumulate maleylpyruvate when exposed to 3-hydroxybenzoate and growth is inhibited. Secondary mutants that have additionally lost 3-hydroxybenzoate monooxygenase are no longer inhibited by the presence of 3-hydroxybenzoate. The 3-hydroxybenzoate monooxygenase gene (mhbM) and the maleylpyruvate isomerase gene (mhbI) are 100% co-transducible by P1 phage.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1573-4919
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary In mammalian tissues, two types of regulation of the pyruvate dehydrogenase complex have been described: end product inhibition by acetyl CoA and NADH; and the interconversion of an inactive phosphorylated form and an active non-phosphorylated form by an ATP requiring kinase and a specific phosphatase. This article is largely concerned with the latter type of regulation of the complex in adipose tissue by insulin (and other hormones) and in heart muscle by lipid fuels. Effectors of the two inter-converting enzymes include pyruvate and ADP which inhibit the kinase, acetoin which activates the kinase and Ca2 + and Mg2 + which both activate the phosphatase and inhibit the kinase. Evidence is presented that all components of the pyruvate dehydrogenase complex including the phosphatase and kinase are located within the inner mitochondrial membrane. Direct measurements of the matrix concentration of substrates and effectors is not possible by techniques presently available. This is the key problem in the identification of the mechanisms involved in the alterations in pyruvate dehydrogenase activity observed in adipose tissue and muscle. A number of indirect approaches have been used and these are reviewed. Most hopeful is the recent finding in this laboratory that in both adipose tissue and heart muscle, differences in activity of pyruvate dehydrogenase in the intact tissue persist during preparation and subsequent incubation of mitochondria.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...