Active transport of glutamine and glutamic acid in membrane vesicles from Mycobacterium phlei

Abstract

In addition to proline, the active transport of glutamine and glutamate was demonstrated in the electron transport particles from Mycobacterium phlei. The uptake of glutamine and glutamic acid proceeded against the concentration gradient with various substrates and was sensitive to respiratory inhibitors and synthetic ionophores. The mode of energy transduction for the uptake of glutamine and glutamate appears to differ from that of proline, since the latter requires Na⁺ although respiration per se is a prerequisite for the uptake of all the three amino acids. Studies with competitive inhibitors suggest that the carrier protein or binding site(s) for glutamine and glutamate are different from that of proline. The transport of proline, glutamine and glutamate occurs in the absence of latent ATPase, arsenate and in the absence of a proton gradient.