Fig. 1
UGGT activity in ER-enriched fractions of Arabidopsis thaliana. a Microsomal membranes were prepared from etiolated Arabidopsis plants as described in the Material and Methods. The membranes were incubated in the presence of denatured SBA and UDP-[14C]glucose. The reaction was finished by adding TCA. The pellet was washed three times and the incorporated radioactivity was determined. Controls in which the SBA acceptor withheld or in which the ER-derived membranes were previously heat-inactivated are also shown. b The reaction was carried out as described above but with bovine thyroglobulin as the acceptor substrate. The proteins were treated with endoglycosidase H (Endo-H) to release the N-linked oligosaccharides that were separated by paper chromatography. The paper was cut and radioactivity determined by liquid scintillation