[Circular dichroism study of amphotericin B interaction with the sterols of Candida albicans strains sensitive and resistant to polyene antibiotics].
The method of circular dichroism (CD) was used to study interaction of amphotericin B with liposomes of egg lecithin containing sterols isolated from sensitive and resistant strains of Candida albicans. Analysis of the CD spectra showed that the antibiotic spectral parameters in the dispersion of liposomes modified with sterols underlie definite changes. In case of sterol isolated from the sensitive culture they were evident from an increase in the relative intensity of the negative extremes at 415, 390 and 370 nm. The contours of the CD spectrum in the region of 350 nm significantly changed proportionally to the antibiotic concentration and during incubation. The CD spectra of amphotericin B in the dispersions of the lecithin liposomes containing sterols isolated from the resistant strain of C. albicans were characterized by an increase in the relative intensity of the negative extremes at 415, 390 and 370 nm. These changes also took place during incubation. Still, the frequency character of the spectrum did not practically change. Only the intensity in the spectral region tested somewhat changed proportionally within an hour. The results indicate that the character of antibiotic interaction with liposomes containing sterols of the sensitive and resistant cultures significantly differs. This means that the changes in the membrane sterol composition (ergosterol and delta 7.22-ergostadien-3 beta-ol were the main sterols of the sensitive and resistant cultures respectively) have a marked effect on the character of the antibiotic interaction with them.
D000666:Amphotericin B / Q000032:analysis / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D002942:Circular Dichroism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004352:Drug Resistance, Microbial; D008081:Liposomes / Q000494:pharmacology; D010713:Phosphatidylcholines / Q000494:pharmacology; D013261:Sterols / Q000032:analysis / Q000494:pharmacology*; D013997:Time Factors
D008081:Liposomes; D010713:Phosphatidylcholines; D013261:Sterols; D000666:Amphotericin B
Izuchenie vzaimodeĭstviia amfoteritsina B so sterinami chuvstvitel'nogo i rezistentnogo k polienovym antibitokam shtammov Candida albicans metodom krugovogo dikhroizma.