Linked Life Data

4066767

Source:http://linkedlifedata.com/resource/pubmed/id/4066767

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1985-12-27
pubmed:abstractText
We have isolated and characterized glycopeptides, derived from mouse and bovine cerebral cortex cells, that inhibit protein synthesis and cell growth of normal but not transformed cells. The inhibitor binds to target cell surfaces, and gangliosides have previously been shown to influence cell sensitivity to the glycopeptides. Preincubation with 3.0 micrograms/ml ganglioside GM1 at 0 degrees C for 3 hr sensitized the mouse L-cell line to the inhibitor, as determined by protein synthesis assays. Preincubation of LM cells with ganglioside GM1 alone did not affect protein synthesis rates. In addition, the gangliosides GD1a and GM3 also sensitized the LM cells to the protein synthesis inhibitory effect of the glycopeptide inhibitor. Binding experiments were performed with 3T3 (sensitive) and LM (insensitive) cells to determine if sensitivity to the glycopeptide inhibitor was reflected in binding of the inhibitor to these cells. Binding of 125I-labeled inhibitor to 3T3 cells was maximal after 60 min at 0 degrees C and saturable at approximately 1 X 10(4) molecules/cell. Furthermore, binding of the inhibitor was dose-dependent, with half-maximal binding at 1.5-2.0 nM and saturation at 8.0-10.0 nM. Scatchard plot analysis indicated that the Kd was about 1 X 10(-9) M and that there are 1 X 10(4) receptors/cell. Binding of the inhibitor to LM cells was maximal after 30 min at 0 degrees C and saturation occurred at 5 X 10(3) molecules/cell. We then examined the possibility that gangliosides are the cellular receptor or co-receptor for the glycopeptide inhibitor. Binding of the inhibitor to ganglioside GM1 was first examined after the ganglioside had been preadsorbed to polystyrene tubes. These experiments indicated that the ganglioside did not bind the inhibitor. Ganglioside-containing liposomes from phosphatidylcholine or LM cell membrane components were also prepared; these artificial membranes did not bind appreciable amounts of the iodinated inhibitor. Competition experiments showed that the gangliosides GM1 and GD1a did not neutralize the protein synthesis inhibitory activity of the glycopeptides, indicating that gangliosides do not directly interact with the glycopeptide inhibitor. In addition, binding of the inhibitor to LM cells preincubated with ganglioside GM1 was studied. Although the binding of the inhibitor to LM cells was one-half that observed for 3T3 cells, incorporation of exogenous gangliosides into LM cells did not result in increased binding of the inhibitor.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/G(M1) Ganglioside, http://linkedlifedata.com/resource/pubmed/chemical/Gangliosides, http://linkedlifedata.com/resource/pubmed/chemical/Glycopeptides, http://linkedlifedata.com/resource/pubmed/chemical/Glycosphingolipids, http://linkedlifedata.com/resource/pubmed/chemical/Growth Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Nerve Tissue Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Platelet Glycoprotein GPIb-IX..., http://linkedlifedata.com/resource/pubmed/chemical/Platelet Membrane Glycoproteins, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Immunologic, http://linkedlifedata.com/resource/pubmed/chemical/asialo GM1 ganglioside, http://linkedlifedata.com/resource/pubmed/chemical/glycoprotein receptor GPIb-IX
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
125
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
427-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
The role of gangliosides in the interaction of a growth inhibitor with mouse LM cells.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't