Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Glyoxysomal and mitochondrial malate dehydrogenase of watermelon (Citrullus vulgaris) cotyledons (1977)
    Springer
    Planta 136 (1977), S. 211-220 
    Details
    ISSN: 1432-2048
    Keywords: Citrullus ; Isoenzymes ; Malate dehydrogenase ; Enzyme subunits ; Mitochondria ; Glyoxysomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Molecular properties of the glyoxysomal and mitochondrial isoenzyme of malate dehydrogenase (EC 1.1.1.37; L-malate: NAD+ oxidoreductase) from watermelon cotyledons (Citrullus vulgaris Schrad.) were investigated, using completely purified enzyme preparations. The apparent molecular weights of the glyoxysomal and mitochondrial isoenzymes were found to be 67,000 and 74,000 respectively. Aggregation at high enzyme concentrations was observed with the glyoxysomal but not with the mitochondrial isoenzyme. Using sodium dodecyl sulfate electrophoresis each isoenzyme was found to be composed of two polypeptide chains of identical size (33,500 and 37,000, respectively). The isoenzymes differed in their isoelectric points (gMDH: 8,92, mMDH: 5.39), rate of heat inactivation (gMDH: τ1/2 at 40°C=3.0 min; mMDH: stable at 40°C; τ1/2 at 60°C=4.5 min), adsorption to dextran gels at low ionic strenght, stability against alkaline conditions and their pH optima for oxaloacetate reduction (gMDH: pH 6.6, mMDH: pH 7.5). Very similar pH optima, however, were observed for L-malate oxidation (pH 9.3–9.5). The results indicate that the glyoxysomal and mitochondrial MDH of watermelon cotyledons are distinct proteins of different structural composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385987
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Glyoxysomal citrate synthase from watermelon cotyledons: immunocytochemical localization and heterologous translation in Xenopus oocytes (1988)
    Springer
    Planta 173 (1988), S. 289-297 
    Details
    ISSN: 1432-2048
    Keywords: Citrate synthase (cell-free synthesis) ; Citrullus (citrate synthase) ; Cotyledon (citrate synthase) ; Glyoxysome ; Xenopus oocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Glyoxysomal citrate synthase (gCS) was purified from crude extracts of watermelon (Citrullus vulgaris Schrad.) cotyledons, yielding a homogenous protein with a subunit MW of 48 kDa. The enzyme was selectively inhibited by 5,5′-dithiobis-(2-nitrobenzoic acid), allowing quantification in the presence of the mitochondrial isoenzyme (mCS). Differences were also observed with respect to inhibition by ATP (k i=2.6 mmol · l-1 for gCS, k i=0.33 mmol · l-1 for mCS). The antibodies prepared against gCS did not cross-react with mCS. The immunocytochemical localization of gCS by the indirect protein A-gold procedure was restricted to the glyoxysomal membrane or the peripheral matrix of glyoxysomes. Other compartments, e.g. the endoplasmic reticulum, were not labeled. Xenopus oocytes were used for the translation of watermelon polyadenylated RNA (poly(A)+RNA). A translation product with a MW of 51 kDa was immunoprecipitated by the anti-gCS antibodies. It was absent in controls without poly(A)+RNA or with preimmune serum. A similar translation product was also immunoprecipitated after cell-free synthesis of watermelon poly(A)+RNA in a reticulocyte system, in contrast to the in-vivo labeled gCS (48 kDa). It was concluded that gCS is synthesized as a higher-molecular-weight precursor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00401015
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Glyoxysomal malate dehydrogenase of watermelon cotyledons: De novo synthesis on cytoplasmic ribosomes (1977)
    Springer
    Planta 134 (1977), S. 277-285 
    Details
    ISSN: 1432-2048
    Keywords: Citrullus ; Enzyme synthesis ; Glyoxysomes ; Malate dehydrogenase ; Seed germination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of glyoxysomal malate dehydrogenase (gMDH, EC 1.1.1.37) during early germination of watermelon seedlings (Citrullus vulgaris Schrad.) was determined in the cotyledons by means of radial immunodiffusion. The active isoenzyme was found to be absent in dry seeds. By density labelling with deuterium oxide and incorporation of [14C] amino acids it was shown that the marked increase of gMDH activity in the cotyledons during the first 4 days of germination was due to de novo synthesis of the isoenzyme. The effects of protein synthesis inhibitors (cycloheximide and chloramphenicol) on the synthesis of gMDH indicated that the glyoxysomal isoenzyme was synthesized on cytoplasmic ribosomes. Possible mechanisms by which the glyoxysomal malate dehydrogenase isoenzyme reaches its final location in the cell are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384194
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...