title: Complex formation between protein and poly vinyl sulfonate as a strategy of proteins isolation.
abstract: The complex formation between the basic protein trypsin and the strong anionic polyelectrolyte poly vinyl sulfonic acid was studied by using turbidimetric and isothermal calorimetric titrations. The trypsin-polymer complex was insoluble at pH lower than 5, with a stoichiometric ratio polymer mol per protein mol of 1:136. NaCl, 0.5M inhibited the complex precipitation in agreement with the proposed coulombic mechanism of complex formation. The protein structure and its thermodynamic stability were not significantly affected by the presence of the polyelectrolyte. The enzymatic activity of trypsin increases throughout time, even in the presence of the polymer.
authors.affiliation: Bioseparation Laboratory, Physical Chemistry Department, Faculty of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 570, S2002RLK Rosario, Argentina.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Braia
authors.forename: María Cecilia
authors.initials: MC
authors.lastname: Porfiri
authors.forename: Beatriz
authors.initials: B
authors.lastname: Farruggia
authors.forename: Guillermo
authors.initials: G
authors.lastname: Picó
authors.forename: Diana
authors.initials: D
authors.lastname: Romanini
mesh_terms: D000818:Animals; D002151:Calorimetry; D011232:Chemical Precipitation; D006863:Hydrogen-Ion Concentration; D009391:Nephelometry and Turbidimetry; D009994:Osmolar Concentration; D011145:Polyvinyls / Q000737:chemistry*; D012995:Solubility; D013451:Sulfonic Acids / Q000737:chemistry*; D013552:Swine; D013816:Thermodynamics; D014357:Trypsin / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D011145:Polyvinyls; D013451:Sulfonic Acids; D014357:Trypsin