Release of protein into the extracellular space as a nonspecific response to stress in Escherichia coli
Roshchina, E.K.; Petrov, L.N.
Mikrobiologiia 66(2): 179-184
1997
ISSN/ISBN: 0026-3656 PMID: 9206752 Document Number: 476412
This paper is concerned with the kinetics of excretion of fluorescent tryptophan-containing proteins from Escherichia coli cells kept in physiological saline at room temperature or incubated at 42, 48, and 55 degrees C. The kinetic curves of the extracellular concentration of protein can be described by parameters T and C, where C is the stationary extracellular concentration of the protein and T is the time in which the given concentration is reached. T was found to be a variable, and C was a constant independent of the type and strength of the stress. During the protein release, the viability of the cells was maintained at the initial level, but, after the concentration of the protein reached a stationary value, the culture cells died exponentially. All this allows the protein release into extracellular medium to be considered as a nonspecific response of E. coli to stress. The protein excretion was analyzed with reference to the data on the kinetics of release of other UV-absorbing compounds from the cells.