Appearance of smaller mannosyl-glycopeptides on the surface of a human cell transformed by simian virus 40.

When fucosyl surface glycopeptides from growing normal human cells (WI 38) were compared with those derived from nongrowing cells the former were enriched in high-molecular-weight species. However, a line of human cells (WI 18Va) transformed by simian virus 40 appeared to have fucosyl-glycopeptides similar in size distribution to those from rapidly growing non-transformed cells (WI 38). I propose that the enrichment in high molecular weight species in these cells might be growth- rather than transformation-dependent. Using radioactive mannose to label surface glycopeptides, I observed that those derived from transformed cells (WI 18Va) were smaller than those from rapidly growing normal cells. Thus differences in size distribution may not be adequate criteria to evaluate the growth-dependent alterations in cell surface glycopeptides.