Effect of surface active additives on partitioning of proteins and enzymes in poly(ethylene glycol)/dextran aqueous two-phase systems

✍ Scribed by Sangita S. Bodhankar; Vilas G. Gaikar

• Publisher: Wiley (John Wiley & Sons)
• Year: 1998
• Tongue: English
• Weight: 251 KB
• Volume: 73
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(1998110)73:3<251::aid-jctb958>3.0.co;2-1

✦ Synopsis

The e †ect of anionic (sodium butylbenzene sulfonate, sodium butylmonoglycol sulfate), cationic (tetrabutyl ammonium bromide), nonionic(Tween 20) and amphoteric (proline) surface active additives on the partitioning of proteins and enzymes, such as BSA, lysozyme, glucose oxidase and b-lactoglobulin, in a bipolymeric aqueous two-phase system of polyethylene glycol and dextran has been studied. The partitioning of proteins and enzymes in the aqueous twophase system is inÑuenced by surface active additives depending upon their structure and charge. The amphiphiles themselves partition unevenly between the two phases. Their e †ect on protein partitioning can be explained on the basis of electrostatic and hydrophobic interactions. In the presence of ionic amphiphiles, proteins have an affinity for the other phase if an amphiphile carrying a charge of the same sign partitions to that phase. The hydrophobic e †ect contributes to protein partitioning if the proteins have signiÐcant members of surface hydrophobic amino acid residues.