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Query: UNIPROT:Q17RS7 (
Gen
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130,125
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
During growth of Escherichia coli strain SPA O in the presence of methionine, an intermediate accumulates in the medium. This intermediate reacts with 2,4-dinitrophenylhydrazine, and can be degraded to ethylene either enzymically or photochemically, the latter being stimulated by the addition of a flavin. The pH optimum for the photochemical degradation of this intermediate and 2-keto-4-methylthiobutyric acid (KMBA) is pH 3 whereas the optimum for methional is pH 6. The enzyme which converts the intermediate to ethylene also converts KMBA to ethylene and has many of the properties of a
peroxidase
including inhibition by catalase, cyanide, azide and anaerobiosis. The enzyme which synthesizes the intermediate is not known but requires oxygen and pyridoxal phosphate. A pathway for ethylene biosynthesis is proposed in which methionine is converted to KMBA which can be degraded either by
peroxidase
or in a flavin-mediated photochemical reaction. Its relevance to the properties of other ethylene-producing bacteria and to the proposed pathway of ethylene release by higher plants is discussed.
J
Gen
Microbiol 1977 Feb
PMID:Evaluation of the role of methional, 2-keto-4-methylthiobutyric acid and peroxidase in ethylene formation by Escherichia coli. 1 80
The location of the glucosylated teichoic acid in whole cells and isolated walls of Streptococcus faecalis 8191 has been investigated using ruthenium red, gold-labelled concanavalin A and concanavalin A-
peroxidase
-diaminobenzidine. Dense laminae were revealed in sections of osmium-fixed walls stained with ruthenium red which corresponded to similar regions stained by uranyl and lead. Such regions were not seen after teichoic acid had been extracted, suggesting that the uptake of stain was by teichoic acid. However, these regions were not labelled on exposure to gold concanavalin A or concanavalin A-
peroxidase
-diaminobenzidine; these stains indicated that teichoic acid was situated between the dense laminae, although the distribution of stain could have been due to the inability of the concanavalin A stains to penetrate deeply. Chemical binding studies showed that the teichoic acid was the major uranyl binding component in isolated walls, from which it might be inferred that teichoic acid was located in the densely staining regions. However, since osmification significantly increased the binding of uranyl (and lead stains) to non-teichoic acid material, such an inference was not necessarily valid. It is concluded that the presence of teichoic acid can be demonstrated in certain regions of the wall by concanavalin A, but its presence in densely staining regions has not been established. These experiments therefore suggest that teichoic acid may not be intimately associated with the mechanisms that generate contrast patterns in stained sections of cell walls of Streptococcus faecalis.
J
Gen
Microbiol 1975 Jul
PMID:An electron microscopic study of the location of teichoic acid and its contribution to staining reactions in walls of Streptococcus faecalis 8191. 5 Apr 6
The location of antigens on sections of bacteria using the soluble
peroxidase
-anti-
peroxidase
complex in conjunction with unlabelled antibody is described. Using this technique, spore antigens have been detected in the cytoplasm of vegetative cells during forespore septum formation and subsequent stages of sporulation. Antigenic sites were first associated with poly-beta-hydroxybutyric acid granules and subsequently were found in increasing quantities in the cytoplasm of the sporangium. Vegetative cell antigens were located on the cell wall and in the cortical region during sporulation. During germination antigens were located in the cortical region, and during outgrowth on the cell wall. These findings are discussed in the light of existing biochemical data.
J
Gen
Microbiol 1975 Jul
PMID:The location of bacterial antigens on sections of Bacillus cereus by use of the soluble peroxidase--anti-peroxidase complex and unlabelled antibody. 5 Apr 8
At sub-bactericidal concentrations of hydrogen peroxide, Mycobacterium tuberculosis was killed by hydrogen peroxide/
peroxidase
/halide microbicidal systems. The halide cofactor could be either iodide or, with much lower efficiency, chloride. Omission of any one of the reactants eliminated the tuberculocidal effect. Differences in susceptibility between different strains of M. tuberculosis did not correlate with virulence differences. The observations are discussed in the context of host defence mechanisms against tuberculosis.
J
Gen
Microbiol 1978 Aug
PMID:Virulence of Mycobacterium tuberculosis and susceptibility to peroxidative killing systems. 9 84
Gonococci were labelled with 125I using the
lactoperoxidase
system. The amount of label incorporated was similar with all strains including those which appeared capsulated. Electrophoresis on sodium dodecyl sulphate-polyacrylamide gels revealed that the major proteins labelled were those found in outer membrane preparations. Comparison of variants of one strain showed that the major outer membrane protein (protein I) was always present and heavily labelled. The second major protein (protein II) was present in variable amounts but labelling was proportional to the amount present. A third protein (III) was only present in outer membranes from a freshly isolated variant but was present in whole cells of each strain. Protein III was not labelled in whole cells but was labelled in outer membrane preparations suggesting that many membranes have their inner surface exposed. The labelling of a strain adapted to growth in guinea-pig chambers failed to reveal any new major surface proteins. The results demonstrate the variation in surface topography possible with variants of one strain of gonococcus but show that one major protein antigen is always expressed on the surface.
J
Gen
Microbiol 1978 Oct
PMID:The surface properties of Neisseria gonorrhoeae: topographical distribution of the outer membrane protein antigens. 10 33
The protein and glycoprotein composition of Kirsten murine leukaemia-sarcoma virus (KiMSV(KiMuLV) was studied using SDS-polyacrylamide gel electrophoresis. Twenty-three polypeptides and three glycoproteins were detected following electrophoresis by staining with Coomassie blue and PAS or by autoradiography of isotopically labelled virus. Protein components were assigned positions in the virus particle, envelope, nucleoid or intermediate area based on iodination with
lactoperoxidase
and sedimentation in potassium citrate equilibrium gradients. The KiMSV (KiMuLV) envelope contained 11 polypeptides and three glycoproteins. The virus nucleoid and intermediate area were each composed of six proteins. The protein composition of KiMSV(KiMuLV) was highly reproducible when virus was harvested from cells of the same subcluture generation. However, the protein profiles were altered with repeated in vitro passages of the virus-producing cell line.
J
Gen
Virol 1975 Jan
PMID:Proteins of Kirsten murine leukaemia-sarcoma virus: localization within the virus particle by iodination and fractionation techniques. 16 14
Surface antigens of BHK-21 cells infected with HSV-1 or HSV-2 were radioiodinated (125I) with
lactoperoxidase
, immune precipitated and analysed by polyacrylamide gel electrophoresis (PAGE). Experiments using antiserum to HSV-1 or HSV-2, absorbed with appropriate hemotypic or heterotypic antigens, revealed that both type-specific (homotypic) and cross-reactive antibody combined with surface glycoproteins to form a single large radioactive peak. This peak, which constituted the major glycoprotein region (region a) observed in electropherograms, represented a range in mol. wt. from 115000 to 130000. Sensitization of cells to complement lysis, neutralization of infectious virus and immune precipitation of surface glycoproteins (region a) were found to be generally correlated properties of all the antibody preparations analysed, including antibody prepared specifically against region a antigens. These findings suggest a major immunological role for the surface glycoproteins migrating in PAGE region a.
J
Gen
Virol 1978 Aug
PMID:Complement-mediated cytolysis of HSV-1 and HSV-2 infected cells: plasma membrane antigens reactive with type-specific and cross-reactive antibody. 21 Nov 89
Adsorption of u.v.-inactivated Sendai virus on to NIL8 hamster cells causes fusion of the cells into polykaryocytes within 2 h. "Infected" cells were incubated at 37 degrees C for periods of 10 min to 8 h and their surface proteins iodinated with [125I] catalysed by
peroxidase
. Structural components of the viral envelope, such as haemagglutin-neuraminidase (HN) and probably also the fusion protein (F) were detected in the cell membrane for periods up to 4 h post infection.
J
Gen
Virol 1975 Nov
PMID:The fate of protein subunits of parainfluenza (Sendai) virus after adsorption to NIL8 hamster embryo cells. 21 28
Infection with herpes simplex virus type 1 (HSV-1) induces different morphological changes in different cell lines. This is demonstrated by comparative scanning (SEM and transmission (TEM) electron microscopic investigations of cell cultures prepared under identical conditions. SEM of HSV-1 infected HEp-2 cells reveals a slightly altered cell surface: only the number of the microvilli is reduced. Large amounts of released virions are detectable adhering to the outer plasma membrane. Ultra-thin sections show typical virus maturation steps in the nuclei (formation of nucleocapsids and virus budding from the inner lamella of the nuclear membrane) and in the cytoplasm (egress of enveloped nucleocapsids through membranous structures). HSV-infected primary chick embryo fibroblast (CEF) cells are characterized by crumpled and rough surfaces without virus particles adhering to the membrane. Ultra-thin sections exhibit atypical virus maturation with many unenveloped nucleocapsids within the cytoplasm. The distribution of HSV-induced antigen(s) on the surface of the infected cells is identical in the two cell systems as determined by the
peroxidase
labelling technique. The c.p.e. (as seen by phase contrast light microscopy) is similar in both HEp-2 and CEF cells: both fusion and rounding up is induced in the infected cells.
J
Gen
Virol 1979 Aug
PMID:Differences in the morphology of herpes simplex virus infected cells: I. Comparative scanning and transmission electron microscopic studies on HSV-1 infected HEp-2 and chick embryo fibroblast cells. 23 Feb 92
Human embryonic kidney cells have been transformed by exposing cells to sheared fragments of adenovirus type 5 DNA. The transformed cells (designated 293 cells) exhibited many of the characteristics of transformation including the elaboration of a virus-specific tumour antigen. Analysis of the polypeptides synthesized in the 293 cells by labelling with 35S-methionine and SDS PAGE showed a variable pattern of synthesis, different in a number of respects from that seen in otheruman cells. On labelling the surface of cells by
lactoperoxidase
catalysed radio-iodination, the absence of a labelled polypeptide analogous to the 250 K (LETS) glycoprotein was noted. Hybridization of labelled cellular RNA with restriction fragments of adenovirus type 5 DNA indicated transcription of a portion of the adenovirus genome at the conventional left hand end.
J
Gen
Virol 1977 Jul
PMID:Characteristics of a human cell line transformed by DNA from human adenovirus type 5. 88 4
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