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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

omparing the interaction of the antibiotic levofloxacin with zwitterionic and anionic membranes: Calorimetry, fluorescence, and spin label studie

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Muniz, Gabriel S. Vignoli [1] ; Souza, Mariana C. [1] ; Duarte, Evandro L. [1] ; Lamy, M. Teresa [1]
Total Authors: 4
[1] Univ Sao Paulo, Inst Fis, BR-05508090 Sao Paulo, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Web of Science Citations: 1

The present work compares the interaction of the antibiotic levofloxacin (LVX) with zwitterionic and anionic liposomes composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3phospho-(1'-rac-glycerol) (DPPG), respectively. By using differential scanning calorimetry (DSC), and with spin labels incorporated into liposomes at two different depths of the bilayers, we investigated the changes induced on the membrane by increasing concentrations of LVX. Further information was obtained using intrinsic LVX fluorescence. Under the conditions used here, all techniques evinced that LVX has little affinity for DPPC zwitterionic membrane. Opposite to that, LVX exhibits a considerable affinity for anionic bilayers, with membrane partition constants K-p = (3.3 +/- 0.5) x 10(2) and (4.5 +/- 0.3) x 10(2), for gel and fluid DPPG membranes, respectively. On binding to DPPG, LVX seems to give rise to the coexistence of LVX-rich and -poor domains on DPPG membranes, as detected by DSC. At the highest LVX concentration used (20 mol%), DSC trace shows an increase in the cooperativity of DPPG gel-fluid transition, also detected by spin labels as an increase in the bilayer packing. Moreover, LVX does not induce pore formation in either DPPG or POPG vesicles. Considering the possible relevance of LVX-membrane interaction for the biological and toxicological action of the antibiotic, the findings discussed here certainly contribute to a better understanding of its action, and the planning of new drugs. (AU)

FAPESP's process: 18/20162-9 - Investigating the Pathogenesis and Drug Resistance in Microorganisms - Characterization and Control of ATP-Binding Cassette Transporters
Grantee:Andrea Balan Fernandes
Support Opportunities: Regular Research Grants
FAPESP's process: 17/25930-1 - Characterization of lipid dispersions of biological relevance: structures and interactions
Grantee:Maria Teresa Moura Lamy
Support Opportunities: Regular Research Grants
FAPESP's process: 14/50983-3 - INCT 2014: complex fluids
Grantee:Antonio Martins Figueiredo Neto
Support Opportunities: Research Projects - Thematic Grants