CARBOHYDRATE CHAIN ANALYSIS BY LECTIN BINDING TO ELECTROPHORETICALLY SEPARATED GLYCOPROTEINS FROM MURINE-B16 MELANOMA SUBLINES OF VARIOUS METASTATIC PROPERTIES

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  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (2) , 791-798
Abstract
Cellular glycoprotein carbohydrate chains of B16 melanoma sublines of various metastatic colonization capacities were analyzed. B16 sublines selected for low (B16-F1) or high lung (B16-F10), high brain (B16-B15b), or high ovary (B16-O13) colonization properties, or high tissue invasiveness in vitro (B16-BL6) were used. The major B16 cell surface sialoglycoproteins were of MW .apprx. 115,000, .apprx. 90,000, .apprx. 82,000, and 60,000 to 65,000. Terminal sialic acid residues in the carbohydrate chains were responsible for WGA binding. However, removal of sialic acid residues followed by Smith degradation resulted in reappearance of WGA-binding sites on these sialoglycoproteins, indicating that the carbohydrate chains possesed at least one branching point at an outer .alpha.-mannosyl residue. This structural feature was further indicated by the failure of 125I-Lens culinaris hemagglutinin to bind to these sialoglycoproteins. The fact that the carbohydrate residues of the MW .apprx. 115,000 .apprx. 90,000, and .apprx. 82,000 sialoglycoproteins were of the complex type was confirmed by their reactivity with 125I-Ricinus communis agglutinin I, which preferentially binds to Gal .fwdarw. GlcNAc sequences after removal of sialic acid in situ. 125I-Peanut (Arachis hypogaea) agglutinin, specific for Gal .fwdarw. GalNAc sequences, failed to bind to the major WGA-reactive sialoglycoproteins, but strongly interacted after removal of sialic acid with MW .apprx. 51,000 and .apprx. 56,000 glycoproteins from sublines B16-F1, -F10, and -BL6 and with a MW .apprx. 63,000 glycoprotein from sublines B16-F10, and -BL6, -O13 and -B15b. Thus, the small, mucin-type carbohydrate chains were expressed almost exclusively on these lower MW sialoglycoproteins, and very little on the MW .apprx. 82,000, .apprx. 90,000, and .apprx. 115,000 sialoglycoproteins. A WGA-binding MW 60,000 to 75,000 sialoglycorprotein was prominent on B16-B15b cells. A. hypogaea agglutinin-binding MW .apprx. 51,000, .apprx. 56,000, and .apprx. 63,000 sialoglycoproteins were present on lung-colonizing sublines, and a L. culinaris hemagglutinin-binding MW .apprx. 50,000 nonsialyated glycoprotein was found on B16-O13 cells.