GLYCOSYLATION OF LIPOPROTEIN-LIPASE IN HUMAN SUBCUTANEOUS LIPOMAS

Glycosylation of lipoprotein lipase (LPL) was studied in human subcuta neous lipomas. Heparin-releasable LPL activities were higher in lipoma s than those in adjacent normal adipose tissues, and showed good corre lation with cellular LPL protein mass. Molecular weight of LPL subunit was 57 kDa in both tissues. After endoglycosidase H-digestion, two ty pes of LPL subunits were found in normal adipose tissues: partially se nsitive (55 kDa) and totally sensitive (52 kDa) form. In lipoma tissue s, the fraction of partially sensitive form (55 kDa) was increased com paring with control adipose tissues. These results suggest that partia lly sensitive subunits constitute the major secretable form of LPL in human subcutaneous lipomas.