Membranes of protein bodies. I. Isolation from cotyledons of germinating cucumber seeds.
Protein bodies were prepared from cotyledons of germinating seeds of cucumber (Cucumis sativus) in different ways: the organelles either obtained from protoplasts by lysis or from cotyledons by mechanical disintegration were separated on sucrose-density gradients. In addition, a non-aqueous procedure was employed to isolate protein bodies. Marker proteins indicative of membranes of other organelles were carefully assayed. By this means contaminations in the purified protein-body fractions could be ruled out. Isolated protein bodies were separated into crystalloids, matrix, and membranes. The membranes were purified and characterized according to their equilibrium density (rho = 1.20 kg/l) on sucrose gradients by flotation or sedimentation. Protein-body membranes labelled in the phospholipid moiety were prepared and analyzed after application of [methyl-14C] choline or [32P] phosphate in vivo.
D000596:Amino Acids / Q000302:isolation & purification; D002458:Cell Fractionation; D002500:Centrifugation, Isopycnic; D004591:Electrophoresis, Polyacrylamide Gel; D007425:Intracellular Membranes / Q000032:analysis*; D008970:Molecular Weight; D009940:Organoids / Q000032:analysis*; D011523:Protoplasts / Q000032:analysis; D012639:Seeds / Q000032:analysis*
D000596:Amino Acids; C014427:cucurbitine