Uncoupler resistance in Escherichia coli: the effect of uncouplers on proline uptake, ATP levels and the transmembrane pH gradient

Uncoupler Resistance in Escherichia coli: the Role of Cellular Respiration

“…In this paper, we extend our earlier work (Jones et al, 1986;Jones & Beechey, 1987), making particular use of NMR spectroscopy to address the question of whether TTFB functions with equal efficacy in strains Doc-S and TUV. We present evidence indicating the active, energyrequiring nature of uncoupler resistance in strain TUV.…”

“…Organisms. E. coli K 12 Doc-S (laci-z+y+a+ pro rrp his met), and its uncoupler-resistant derivative strains TUV and CUV have been described previously (Ahmed & Booth, 1983;Jones & Beechey, 1987). E. colistrains MRE600 and 553 RP4, both with wild-type cell walls, were also used.…”

“…Growth media. LB medium and succinate minimal medium were as given previously (Jones & Beechey, 1987). Glycerol minimal medium contained 5 ml glycerol l-', replacing succinate.…”

“…Growth. Cells were maintained and grown essentially as before (Jones & Beechey, 1987), except that growth was at 37 "C and was monitored spectrophotometrically at 600 nm.…”

“…To avoid introducing errors from Scatchard linearization, Kd was estimated directly from the binding curve data, using the Marquardt algorithm for non-linear regression (Duggleby, 1984). The procedure for monitoring deoxycholate sensitivity has been described previously (Jones & Beechey, 1987); tests of novobiocin sensitivity were conducted in an identical manner.…”