ИСТИНА

Using the TEMPO radical as a spin probe, it was shown that nanoscale inhomogeneities exist in solutions of PNIPAM and BSA. The structure of these inhomogeneities in protein and polymer solutions is different. At BSA concentrations of ~10%, the formation of inhomogeneities in solution was observed already at 273–295 K. Addition of BSA and collagen to a PNIPAM solution leads to an increase in the proportion of probe molecules located in polymer-protein inhomogeneities along compared to a protein-free solution. It was shown by EPR spectroscopy of spin-labeled PNIPAM and turbidimetry that the addition of proteins promotes PNIPAM chains collapse in the temperature interval near LCST: the fraction of slowly rotating label particles in the globule increases with increasing protein concentration.