Colicins, spermine and cephalosporins: a competitive interaction with the OmpF eyelet
| Autor: | Anne H. Delcour, Valérie Simonet, Jean-Marie Pagès, Ramkumar Iyer, Jérôme Bredin |
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| Rok vydání: | 2003 |
| Předmět: |
Models
Molecular inorganic chemicals Blotting Western Mutant Colicins Porins Spermine Biology medicine.disease_cause Binding Competitive Biochemistry Epitope Structure-Activity Relationship chemistry.chemical_compound Drug Resistance Bacterial Escherichia coli medicine Structure–activity relationship Molecular Biology technology industry and agriculture Biological Transport Cell Biology biochemical phenomena metabolism and nutrition Anti-Bacterial Agents Cephalosporins Kinetics chemistry Colicin Mutation Porin bacteria lipids (amino acids peptides and proteins) Efflux Research Article |
| Zdroj: | Biochemical Journal. 376:245-252 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj20030814 |
| Popis: | The L3 loop is an important feature of the OmpF porin structure, contributing to both channel size and electrostatic properties. Colicins A and N, spermine, and antibiotics that use OmpF to penetrate the cell, were used to investigate the structure–function relationships of L3. Spermine was found to protect efficiently cells expressing wild-type OmpF from colicin action. Among other solutes, sugars had minor effects on colicin A activity, whereas competitions between colicin A and antibiotic fluxes were observed. Among the antibiotics tested, cefepime appeared the most efficient. Escherichia coli cells expressing various OmpF proteins mutated in the eyelet were tested for their susceptibility to colicin A, and resistant strains were found only among L3 mutants. Mutations at residues 119 and 120 were the most effective at conferring resistance to colicin A, probably due to epitope structure alteration, as revealed by a specific antipeptide. More detailed information was obtained on mutants D113A and D121A, by focusing on the kinetics of colicin A and colicin N activities through measurements of potassium efflux. D113 appeared to play an essential role for colicin A activity, whereas colicin N activity was more dependent on D121 than on D113. |
| Databáze: | OpenAIRE |
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