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
    Endoplasmic reticulum and glyoxysomal membranes from castor-bean endosperm: interaction between membrane glycoproteins and organelle matrix proteins (1983)
    Springer
    Planta 157 (1983), S. 143-149 
    Details
    ISSN: 1432-2048
    Keywords: Endoplasmic reticulum ; Glycoprotein ; Glyoxysome ; Membrane protein ; Ricinus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sealed membrane vesicles were prepared from microsomes and glyoxysomes isolated from the endosperm tissue of germinating castor bean. Peripheral-membrane proteins together with soluble protein present in the luminal space of the microsomes or the matrix of the glyoxysomes were released from intact organelles by osmotic shock in the presence of salt. The washed membrane vesicles were linked to cyanogen-bromide-activated Sepharose. Where appropriate, the immobilized vesicles were made permeable to protein molecules by controlled detergent treatment which did not result in significant solubilization of the lipid bilayer. Released luminal proteins were allowed to interact with the membrane vesicles under conditions which gave them access to the cytoplasmic surface only or to both the cytoplasmic and luminal surfaces. While microsomal luminal proteins did not interact with either surface of the membrane vesicles, glyoxysomal matrix proteins specifically bound to the luminal surface of the glyoxysomal membrane. Binding seemed to be effected via the oligosaccharide chains of glyoxysomal membrane glycoproteins since (a) bound proteins could be released by elution with sugar solution, and (b) solubilized glyoxysomal membrane proteins specifically interacted with immobilized lectins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00393648
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Formation of lipid-linked mono- and oligosaccharides from GDP-mannose by castor bean endosperm homogenates (1979)
    Springer
    Planta 146 (1979), S. 91-99 
    Details
    ISSN: 1432-2048
    Keywords: Glycoprotein ; Monosaccharide lipid ; Oligosaccharide lipid ; Polyisoprenol ; Ricinus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A crude organelle preparation from germinating castor bean endosperm catalysed the incorporation of mannose from GDP[14C]mannose into acid-labile mannolipids. Solubility and chromatographic properties have identified the most rapidly synthesized products as mannosyl-phosphoryl-polyisoprenol, while the more polar lipid formed was shown to contain oligosaccharide. Little radioactivity from GDP[14C]mannose accumulated in insoluble product in the cell-free system, but supplying GDP[14C]mannose to intact endosperm tissue has shown that the major incorporation product in vivo is glycoprotein. This product was readily solubilized by either pronase or sodium dodecyl sulphate treatment suggesting it was membrane bound glycoprotein. Incorporation of mannose into mannosyl-phosphoryl-polyisoprenol during the cell-free assay was stimulated by the addition of dolichol monophosphate. This enzymic activity was optimal at pH 7.5 and in the presence of 10 mM Mg2+. The Km for GDP-mannose was estimated to be 5×10-7 M. Cellular mannosyl transferase activity changed markedly during early post-germinative growth; from being absent in the dry seed, enzyme activity increased to peak between the second and third days of growth and subsequently declined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00381260
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Subcellular localization of mannosyl transferase and glycoprotein biosynthesis in castor bean endosperm (1979)
    Springer
    Planta 146 (1979), S. 147-153 
    Details
    ISSN: 1432-2048
    Keywords: Endoplasmic reticulum ; Glycoprotein ; Glyoxysomes ; Microsomes ; Ricinus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Differential and sucrose density gradient centrifugation have shown that the mannosyl transferase present in germinating castor bean endosperm cells which catalyses the synthesis of mannosyl-phosphoryl-polyisoprenol is exclusively located in the endoplasmic reticulum membrane. This intracellular location was confirmed using both ribosome-denuded microsomes isolated in the presence of EDTA and rough-surfaced microsomes isolated in the presence of excess Mg2+ added to maintain ribosome-membrane attachment. Separation of organelles following the incubation of crude particulate fractions with GDP[14C]mannose demonstrated that most of the mannolipid thus formed remained associated with the microsomal fraction. When organelles were isolated from intact tissue which had previously been incubated with GDP[14C]mannose, [14C]glycoprotein was found to be associated with other cellular fractions in addition to the microsomes, in particular the glyoxysomes. The kinetics of radioactive labelling of these organelles suggest that [14C]glycoprotein appears initially in the microsomal fraction and subsequently accumulates in the glyoxysomes. Subfractionation of isolated, [14C]glycoprotein-labelled glyoxysomes established that over 80% of the total radioactivity was present in the membrane, while sodium dodecyl sulphate-polyacrylamide gel electrophoresis of solubilized glyoxysomal membranes showed that the [14C]sugar moiety was associated with several, but not all, constituent polypeptides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00388225
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Incorporation of D-[14C]galactose into organelle glycoprotein in castor bean endosperm (1978)
    Springer
    Planta 141 (1978), S. 329-332 
    Details
    ISSN: 1432-2048
    Keywords: Endoplasmic reticulum ; Glycoprotein ; Glyoxysomes ; Membranes ; Microsomes ; Ricinus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Excised casto bean (Ricinus communis L.) endosperm tissue supplied with [14C]galactose incorporates radioactivity into particulate cell components. Fractionation of homogenates established that 14C-labeled trichloroacetic acid-insoluble material was located primarily in the microsomal and glyoxysomal fractions. The capacity of the tissue to incorporate [14C]galactose into organelle glycoprotein varied during seedling development, increasing during the first 3 days of germination and subsequently declining. The kinetics of incorporation into the major organelle fractions of 2-day old endosperm tissue showed that the endoplasmic reticulum was immediately labeled whereas a lag period preceded the labeling of glyoxysomes. Sub-fractionation of the isolated organelles established that the greatest proportion of the [14C]-galactose labeled glycoprotein was located in the membrane, although a significant incorporation into the matrix protein was also observed. The results indicate that the addition of the carbohydrate moiety to the polypeptide cores occurs in the endoplasmic reticulum during or immediately after their synthesis on membrane-bound ribosomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00388352
    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...