Fluorescent study of the interaction of drugs (tilorone, levana, phenazepam, gidazepam, diazepam, propoxazepam) with human serum albumin by protein fluorescence quenching

Research: applied

Prospect for further application: will be continued as a target application. The application of the developed methods of analysis is possible on the scale of the pharmaceutical enterprise INTERCHEM.

Research level: no analogues in Ukraine

What additional actions require further research: further research requires additional funding for the purchase of modern scientific equipment.

Brief description, positive qualities, further perspective.

The aim of the work is to establish the nature of the interaction of certain drugs with human serum albumin and certain binding parameters by the luminescent method of analysis, as well as to scientifically substantiate the approach for determining the parameters of the binding of SAL to LR molecules by quenching their own fluorescence. A spectroscopic study of the interaction of some LRs with human serum albumin was carried out. The constants and the number of binding sites, the average distances between donor and acceptor molecules for SAL-LR systems have been established. It was shown that LRs quench their protein fluorescence as a result of static interaction in the SAL-LR system.

The thermodynamic parameters of the binding of some LRs with SAL have been determined, and it has been established that van der Waals interactions and the formation of hydrogen bonds play an important role in binding. Such a standardized study of the interaction between SAL and LR is useful for the pharmaceutical industry and clinical medicine.

The conformational changes in LAL caused by binding to LR were studied by measuring synchronous fluorescence spectra. It has been shown that almost all LRs show changes in the protein conformation near the tryptophan residue and almost no change in the environment of the tyrosine residue. Using the complex compound SAL-diazepam as an example, the results of fluorescent analysis were compared with X-ray diffraction studies. It has been shown that the results of determining the average distance between the active site of protein binding and LR by the fluorescent method are in satisfactory agreement with the results of X-ray diffraction analysis, which makes it possible to propose the fluorescence method as an alternative to the more expensive and time-consuming X-ray method of analysis.

A highly sensitive method for the luminescent determination of residual amounts of propoxazepam on the surfaces of pharmaceutical equipment has been developed and validated (detection limit 0.5 µg/ml).

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