Mechanism of L-Lysine Transport by Pea Protoplasts

Abstract
Dureja, I., Guha-Mukherjee, S. and Prasad, R. 1986. Mechanism of L-lysine transport by pea protoplasts.—J. exp. Bot. 37: 549–555. L-Lysine uptake was studied in pea protoplasts to characterize the transport process. The uptake was pH dependent with optimum at pH 5·8. A kinetic analysis of uptake showed that L-lyslne uptake was biphasic. The respiratory inhibitors, sodium arsenate, azide, iodoacetate and 2, 4, dinitrophenol, inhibited the uptake of L-lysine at a final concentration of 0·1 mol m−3 suggesting it to be mediated in part by an active process. Competitive inhibition of L-lysine uptake by only L-arglnine and of L-leucine and glycine uptake by several amino acids indicated that L-lysine uptake occurs via a specific system whereas the uptake of L-leucine and glycine was mediated through a relatively non-specific permease.