BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF SUCROSE AND AMINO-ACID CARRIERS IN RICINUS-COMMUNIS

The use of energized plasma membrane vesicle preparations from cotyled ons and roots of Ricinus communis seedlings is described, and evidence is presented for the existence of plasma membrane H+/sucrose and H+/a mino acid symporters. Using fractions isolated from roots, there is ev idence for at least two carriers which can transport neutral amino aci ds and one which can also transport basic amino acids. A method for th e solubilization and reconstitution of glutamine transport activity is described. Preliminary results on the molecular characterization of t wo putative amino acid carriers and a putative sucrose transporter fro m Ricinus are presented.