title: [Cooperative interaction of serum albumin with quaternized poly-4-vinyl pyridine and structure of the complexes].
abstract: Interaction of bovine serum albumin (BSA) with quaternized poly-4-vinyl pyridine (PE) in aqueous solutions at pH 7 was studied. It was shown that in a wide range of the ratios of the components (nBSA/nPE) soluble stable cooperative complexes were formed. At the same time a certain critical content of the protein exists at which the system loses its homogeneity. Complex formation is not accompanied by protein denaturation. At smaller nBSA/nPE ratios non-homogeneous distribution of protein globulas among polyelectrolite macromolecules was found; this corresponded to the "all or none" principle. Using ultracentrifugation technique viscosimetric measurements and electron microscopy it was shown that the soluble complexes exist in the form of rode-like particles consisting of protein globules stabilized by polycation chains. Such particle can be considered as a model of nucleoprotein complex. At certain crytical nBSA/nPE rations the rod-like particles aggregate with additional number of BSA-molecules and form more complicate soluble and insoluble cooperative complexes. Possible structural models of the complexes described were suggested and the thermodinamic and kinetic cryteria of their self-assembly were discussed.
mesh_terms: D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008854:Microscopy, Electron; D008954:Models, Biological; D009698:Nucleoproteins; D011145:Polyvinyls; D011485:Protein Binding; D011487:Protein Conformation; D012710:Serum Albumin, Bovine; D014783:Viscosity
chemical_list: D009698:Nucleoproteins; D011145:Polyvinyls; D012710:Serum Albumin, Bovine
vernacular_title: Kooperativnoe sviazyvanie syvorotochnogo al'bumina kvaternizovannymi poli-4-vinilpiridinami i struktura obrazuiushchikhsia kompleksov.