DIPEPTIDYL PEPTIDASE-IV IN C6 RAT GLIOMA CELL-LINE DIFFERENTIATION

The C6 rat glioma cell line is broadly used as a model in studies of g lial cell differentiation. In the present study we demonstrated a sign ificantly higher total cellular, but especially membrane-associated, a ctivity of dipeptidyl peptidase IV in differentiated C6 cells in compa rison with their proliferating counterparts. The majority, but not all , of enzyme isoelectric focusing isoforms from differentiated C6 cells displayed a substantially higher activity compared to the proliferati ng cells, with G-P-NHMec as the substrate. Non-denaturing polyacrylami de gradient gel electrophoresis showed the presence of one major peak of activity, dipeptidyl peptidase IV (M-r of about 220000), in both pr oliferating and differentiated C6 cells. The results indicate that dip eptidyl peptidase IV regulation is associated with C6 rat glioma cell differentiation.