Table II.

Distribution of latent UDPase, callose synthase, and GalAT activities in membranes collected by discontinuous density gradient centrifugation

Gradient FractionLatent UDPaseCallose SynthaseGalAT2-a
μmol PO4released min−1 nmol Glc incorporated min−1± se pmol GalA incorporated min−1 ±se
GV145.5463.9 ± 70.81,453.3 ± 150.9
33%49.6585.5 ± 98.20
ER31.6465.6 ± 43.3 200.5 ± 48.2
38%15.7768.2 ± 52.00
Pellet11.6404.0 ± 70.80

Total enzyme activity in each gradient fraction is shown. The data are the average of duplicate samples ± se from one gradient. Similar results were obtained in two separate gradients.

    • F2-a  Assayed with 0.92 μM UDP-[14C]GalA and 100 μM UDP-GalA.