Patent ID: 7166474

Claim:
A method for ESR-spectroscopic investigation of an albumin-containing sample using a spin probe comprising the following steps: determining changes in transport properties of albumin in an albumin-containing sample, wherein the determining includes inducing specific conformational changes of the albumin in the sample under investigation by adding at least three different concentrations of a spin probe binding to the albumin and, at least three different concentrations of a polar reagent to aliquots of the sample, determining degree of change in parameters of binding of the spin probe to specific binding sites of the albumin as a function of the spin probe concentration and the concentration of polar reagent, with reference to ESR spectra of the aliquots added with the spin probe and the polar reagent, using a computer simulation of the ESR spectra, calculating change in the transport properties of the albumin from the changes of the values of the binding parameters of the spin probe for the conformational states of the albumin induced by the different concentrations of spin probe and polar reagent, wherein the concentrations of spin probe to be added are selected such a that a mean value of the ratio of spin probe concentration to albumin concentration is from 2.0 to 3.0, starting from the mean value, selecting at least two additional concentrations of spin probe whose deviation from the mean value is no less than 1.0 and concentrations of polar reagent to be added, such that a mean value of a final concentration of polar reagent is from (0.35·Cp) to (0.85·Cp), wherein Cp represents a critical concentration of polar reagent, surpassing of which would result in denaturing of the albumin, and starting from the mean value of the final polar reagent concentration, selecting at least two additional concentrations of polar reagent whose deviation from the final polar reagent concentration mean value is at least 15%, and adding spin probe in a concentration deviating not lass than 1.0 from the mean value of the ratio and polar reagent in a concentration between (0.35·Cp) and (0.85·Cp) to respective aliquots of the sample, such that at least one aliquot includes a low concentration of the spin probe and a low concentration of the polar reagent, at least one aliquot includes a medium concentration of the polar reagent and a medium concentration of the spin probe, and at least one aliquot includes a high concentration of the spin probe and a high concentration of the polar reagent.