Purification of an autocatalytic protein-glycosylating enzyme from cell suspensions ofDaucus carotaL.

摘要

A glycosyltransferase was identified in the 174 000 ·gmembrane pellet and the supernatant from extracts of cell suspensions ofDaucus carotaL. The enzyme from the supernatant was enriched 475-fold, and sodium dodecyl sulfate-gel electrophoresis and fluorography of this purified sample showed that the only enriched protein band (40 000 Da) was simultaneously an enzyme and a glucose-acceptor. Gel filtration and electrophoresis under non-denaturing conditions proved that in vivo this protein provides the subunits for a very large molecule. Radio-gas-liquid chromatography demonstrated that only one glucosyl moiety was transferred from UDP-glucose to the protein