ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract In contrast to stringent (relA+) cells of Escherichia coli, relaxed (relA) cells excreted recombinant proteins (β-lactamase, interferon α1) into the culture medium during amino acid limitation. Comparative analyses of overall fatty acid composition in relA+ cells and relA cells were performed and revealed that, in wild-type cells, drastic alterations occurred during the stringent response. The portion of saturated fatty acids (C16 : 0) and the fractions of cyclopropane fatty acids (C17cyc and C19cyc) increased whereas the portions of unsaturated fatty acids (C16 : 1 and C18 : 1) decreased. In cells of the relaxed mutant, no significant changes in the overall composition of the fatty acids were observed after the onset of amino acid limitation. These results indicate that a change in fatty acid composition of membrane lipids after starvation of cells may be responsible for the prevention of loss of cellular proteins into the culture medium in stringent controlled cells of Escherichia coli.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002530050375
