ISSN:
1432-072X
Keywords:
(3H) Tetracycline purification
;
Initial uptake kinetics
;
Monophasic tetracycline uptake
;
Tetracycline binding
;
Temperature effect on tetracycline uptake
;
Escherichia coli
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Experiments measuring the initial uptake of commercial (3H) tetracycline exhibit two distinct kinetic phases: a rapid phase followed by a slow phase. (3H) tetracycline purified by chromatography on a Dowex 50WX2 column exhibited only monophasic rapid uptake when tested with susceptible Escherichia coli cells. Cyanide inhibited the uptake of purified (3H) tetracycline only partially while transport of proline and maltose was entirely abolished. Energy independent accumulation of tetracycline may be accounted for by binding to cellular constituents. Uptake of tetracycline-as measured by inhibition of β-galactosidase synthesis-was strongly affected by a shift in temperature from 37°C to 21°C while carrier-mediated transport systems revealed only minor reductions. Taken together with the non-saturability of tetracycline uptake and the evidence for diffusion of tetracycline through phospholipid bilayers [Argast and Beck (1984) Antimicrob Agents Chemother 26:263–265] these data support the hypothesis that tetracycline enters the cytoplasm by diffusion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00408069
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