Metabolism of Basic Amino Acids in Pseudomonas putida

Pseudomonas putida P2 (ATCC 25571) grown on l-lysine or dl-pipecolic acid is induced for a high velocity lysine transport system. Double reciprocal plots of l-lysine transport in induced cells are linear. Km and Vmax values are 7.3 x 10-6 m and 130 nmoles per min per mg for lysine-grown cells and 9.3 x 10-6 m and 42 nmoles per min per mg for cells grown on pipecolate. Lysine transport is optimal at 30° and at pH 6.5 to 7.5, and is inhibited by azide and by cyanide. Induction of the transport system is accompanied by an increase in the levels of enzymes of lysine catabolism. d-Lysine and the d- and l-isomers of arginine and ornithine inhibit l-lysine transport, and l-ornithine and l-arginine are transported by lysine-grown cells. Structural features important for inhibition of l-lysine transport include α-amino and α-carboxyl groups and a positive charge removed from the α-carbon by three to four methylene groups. Similar Michaelis constants, temperature profiles, and responses to a wide range of amino acids and amines are found for l-lysine transport by cells grown either on lysine or pipecolate.