title: Uptake of Branched-Chain Amino Acids by Streptococcus thermophilus.
abstract: The transport of branched-chain amino acids in Streptococcus thermophilus was energy dependent. The metabolic inhibitors of glycolysis and ATPase enzymes were active, but the proton-conducting uncouplers were not. Transport was optimal at temperatures of between 30 and 45 degrees C and at pH 7.0 for the three amino acids leucine, valine, and isoleucine; a second peak existed at pH 5.0 with valine and isoleucine. By competition and kinetics studies, the branched-chain amino acids were found to share at least a common transport system.
authors.affiliation: Laboratory of Applied Biochemistry, University of Nancy I, 54506 Vandoeuvre-les-Nancy, Cedex France.
authors.forename: K M
authors.initials: KM
authors.lastname: Akpemado
authors.forename: P A
authors.initials: PA
authors.lastname: Bracquart