Search

Your search keyword '"Penyige A"' showing total 4 results
Start Over Author "Penyige A" Journal biochemical and biophysical research communications
4 results on '"Penyige A"'

2. Depolarization of the membrane potential by beta-lactams as a signal to induce autolysis

Author

János Matkó, György Barabás, Andrea Bodnár, András Penyige, and Eleonóra Deák

Subjects
Autolysis (biology), Lysis, Biophysics, Ionophore, Cefotaxime, Biochemistry, Membrane Potentials, chemistry.chemical_compound, polycyclic compounds, Drug Interactions, Elméleti orvostudományok, Coloring Agents, Molecular Biology, Membrane potential, biology, Ionophores, Gramicidin, Streptomyces griseus, Depolarization, Penicillin G, Orvostudományok, Cell Biology, Carbocyanines, biology.organism_classification, Anti-Bacterial Agents, Membrane, chemistry, Autolysis
Abstract

The effect of beta-lactam antibiotics that are known to inhibit cell wall biosynthesis and induce cell wall autolysis on the electrophysiological state of the plasma membrane in Streptomyces griseus was studied. Addition of various beta-lactam antibiotics induced a dose- and growth-stage-dependent depolarization of the membrane potential of Streptomyces griseus. The hydrolyzed biologically inactive derivative penicilloic acid had no depolarizing effect on the membrane potential. The ionophore gramicidin D, while depolarizing the membrane potential, also induced a dose-dependent increase in cell wall lysis. These observations suggest that alteration of the transmembrane potential could be an important signal in triggering cell wall autolysis of S. griseus. more...

Published
2002

Catalog

Books, media, physical & digital resources
See catalog results

4. Modification of Glutamine Synthetase in Streptomyces griseusby ADP-Ribosylation and Adenylylation

Author

Penyige, A., Kalmanczhelyi, A., Sipos, A., Ensign, J.C., and Barabas, G.

Abstract

Addition of NH+4to Streptomyces griseus2682 cells grown in NO−3containing medium resulted in a rapid decline in glutamine synthetase activity due to covalent modification of the enzyme. The NH+4promoted inactivation of the enzyme was inhibited by the ADP-ribosyltransferase inhibitor 3-methoxybenzamide. In the presence of ADP-ribosyltransferase activity the purified glutamine synthetase was also inhibited by NAD+in a concentration-dependent manner. ADP-ribosylation of glutamine synthetase was demonstrated in vitroby showing the incorporation of labeled ADP-ribose from [α-32P]NAD+into glutamine synthetase subunits. Beside ADP-ribosylation, adenylylation of glutamine synthetase was also shown in S. griseussince phosphodiesterase I treatment reactivated the enzyme in crude extracts of NH+4-shocked cells. Glutamine synthetase was also inhibited and modified by ATP in crude cellular extracts. These results suggest that in S. griseus2682 ADP-ribosylation of glutamine synthetase could be an alternative modification to adenylylation to regulate glutamine synthetase activity. more...

Published
1994
Full Text
View/download PDF