GLYCOSYLATION AND DEGLYCOSYLATION OF PROTEASOMES (PROSOMES) FROM CALF-LIVER CELLS - HIGH ABUNDANCE OF NEURAMINIC ACID

Proteasomes (prosomes) of calf-liver cells were probed with three diff erent biotinylated lectins: Limulus polyphemus agglutinin (LPA), speci fic for neuraminic acid; Solanum tuberosum agglutinin (STA), specific for GlcNac; and concanavalin A (Con A), specific for Man/Glc. While on ly one proteasomal protein reacted with STA, most of the proteasomal p roteins reacted with LPA and several with Con A. Deglycosylation with N-glycosidase F showed that the detected glycan residues were asparagi ne-linked. Finally we demonstrate an alternative method for the isolat ion of proteasomes based on the affinity of certain proteasomal protei ns to Con A.