Proteins pattern alteration in AZT-treated K562 cells detected by two-dimensional gel electrophoresis and peptide mass fingerprinting

In this study we report the effect of AZT on the whole protein expression profile both in the control and the AZT-treated K562 cells, evidenced by two-dimensional gel electrophoresis and peptide mass fingerprinting analysis. Two-dimensional gels computer digital image analysis showed two spots that appeared up-regulated in AZT-treated cells and one spot present only in the drug exposed samples. Upon extraction and analysis by peptide mass fingerprinting, the first two spots were identified as PDI-A3 and stathmin, while the third one was proved to be NDPK-A. Conversely, two protein spots were present only in the untreated K562 cells, and were identified as SOD1 and HSP-60, respectively

The interaction of the polyene antibiotic lucensomycin with cholesterol in erythrocyte membranes and in model systems. I. A fluorometric and spectrophotometric study.

The increase of fluorescence emission of lucensomycin occurring upon interaction with cholesterol, either as colloidal suspension or included in phospholipid micelles or in erythrocyte membranes, was described. Colloidal cholesterol differed from that contained in membranes by the kinetic behavior of its interaction with lucensomycin, the reaction being very slow in the former case, very fast in the latter one. Variations of optical density also occurred, though neither the kinetics nor the titration curves were superimposable on those obtained fluorometrically. The stoichiometry was, however, the same

A comparative study of the hemolytic effect of polyenic antibiotics and of other cholesterol-binding agents.

Macrocyclic polyenic antibiotics were compared, on the basis of their hemolytic efficiency (expressed as critical occupancy level and as mean intrinsic association constant) with each other and with other cholesterol-specific hemolytic agents, such as digitonin and streptolysin O. In all cases, except for the larger polyenic antibiotics (amphotericin B and nystatin), the experimental results were compatible with the existence in the membrane of a large number of identical binding sites which are independent from each other. Simultaneous addition of two different agents gave either synergistic or antagonistic effects, indicating that digitonin, streptolysin O and filipin have different mechanisms of action from each other and from the mycosamine-containing polyenes