Table 2.

Effect of transport-activating conditions on energies of activation for the rate of transport of glycine betaine in L. monocytogenes membrane vesiclesa

ConditionTemp range (°C)SlopebEa(kcal/mol)c
600 mOsm KCl18–30+520
12–18−3,99018.3
4–10−10,50048.1
600 mOsm sucrose18–30−7503.4
12–18−3,96018.1
4–10−10,61048.6
Low tempd 4–15+6,020−115
  • a All systems were energized by addition of ascorbate-PMS.

  • b Values were obtained from data in Fig. 3 and5.

  • c Ea = −2.303R × (slope of Arrhenius plot).

  • d In the absence of osmotic stress.