Effects of heat and other agents on amino acid uptake in Escherichia coli

Abstract

In Escherichia coli K1060 grown at 37°C we observed that the uptake of both L-[³H]leucine and L-[³⁵S]methionine was inhibited by exposure of the cells to 48°C. The calcium channel Mockers diltiazem and verapamil, and the anti-arrhythmic agent quinidine, inhibited the uptake of L-[³H]leucine at both 37°C and 48°C. Verapamil also inhibited the uptake of L-[³⁵S]methionine at 37°C, but at 48°C protected against some of the heat-induced decrease in the uptake of this amino acid. The local anaesthetic procaine markedly inhibited the uptake of both labelled amino acids at temperatures between 37°C and 48°C. Amino acid uptake and cell killing were not correlated.

Key Words:

• Amino acid uptake
• heat
• drugs