Release of malignancy-related fucopeptides from ascites tumour cells in association with membrane vesicles.
Membrane vesicles were found to be released from Landschütz ascites cells in vivo and in vitro. Vesicle fractions were highly enriched in the large fucopeptides which are a known feature of malignant cell membranes. Incubation with trypsin in vitro is commonly used to release these fucopeptides from tumour cells. The present results show that the enzyme acts by increasing the release of lipid vesicles enriched in these components, rather than by liberating soluble tryptic products. Thus, the parent molecules in the cell would appear to be integral membrane proteins which are insensitive to direct cleavage by trypsin.
Walsh
E
E
Department of Biochemistry, University College, Belfield, Dublin, Ireland.
Smyth
H
H
McGuinness
M
M
D000818:Animals; D001202:Ascitic Fluid / Q000032:analysis / Q000378:metabolism; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D002784:Cholesterol / Q000032:analysis / Q000378:metabolism; D005643:Fucose / Q000032:analysis* / Q000378:metabolism; D007553:Isotope Labeling; D051379:Mice; D014357:Trypsin / Q000378:metabolism
D005643:Fucose; D002784:Cholesterol; D014357:Trypsin