Molecular Targets of the Hydrophobic Block of Pluronics in Cells: a Photo Affinity Labelling Approachстатья
Статья опубликована в высокорейтинговом журнале
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 7 марта 2019 г.
Аннотация:Purpose
Pluronics are known as inhibitors of multidrug resistance thus making tumor cells sensitive to therapeutic doses of drugs. The purpose of our study consists in revealing molecular targets of the hydrophobic poly(propylene oxide) block of pluronics in living cells and the dependence of the polymers chemosensitizing efficiency upon targeting.
Methods
A photo sensitive tracer was attached to the hydrophobic poly(propylene oxide) block of 3H-labeled tert-Bu-EO-PO copolymer. The conjugate was used for treatment cells in culture. We searched for its complexes with cellular lipids or proteins using RP TLC and SDS-electrophoresis, respectively. The chemosensitizing efficiency of pluronics was evaluated by their least concentrations sufficient for MDR reversion (CMDR).
Results
The poly(propylene oxide) block inserts in the lipid core of plasma membrane. No preferential binding of the conjugate with any cellular protein, particularly P-gp, has been detected. FITC-labeled pluronic L61 bound to alcohol insoluble cellular targets did not participate in MDR reversion. CMDR values of 13 block copolymers have been determined. These values inversely correlated with the polymers affinity toward lipids and the ability to accelerate flip-flop.
Conclusion
Insertion of the hydrophobic poly(propylene oxide) block of amphiphiles in the lipid core of plasma membrane and acceleration of flip-flop of lipids underlie the mechanism of MDR reversion.
KEY WORDS
cellular membranes lipids multidrug resistance polymers polymer-biopolymer interaction