GB818520A - Protein complexes - Google Patents

Abstract

Proteinaceous materials in a highly purified or undenatured form are isolated by adding a completely or partially fluorinated aliphatic acid, amine, alcohol or alcohol derivative, having at least four carbon atoms, or a salt thereof, which provides in aqueous solution an anion or cation with a non-polar group, to a solution of at least one proteinaceous material to form a fluoro compound-protein complex, adjusting the pH of the solution to precipitate the complex and removing the fluoro compound from the separated complex, e.g. by dilution, dialysis, or ion-exchange procedure. The pH of the solution is such that the fluoro compound and the protein carry like charges, the pH adjustment being to substantially the isoelectric point of the protein or a region where the fluoro compound and the protein carry unlike charges. A plurality of proteins having different isoelectric points may be separated from a mixture thereof by repeatedly adjusting the pH of the solution to precipitate the individual protein-complexes and liberating the protein from each separated complex. Proteins mentioned are ovalbumin, gelatin, human serum albumin, fibrinogen, bovine gamma globulin, beta-lactoglobulin viruses, antitoxins and enzymes such as urease. Specified fluoro compounds are perfluorobutyric, caproic, caprylic, capric and lauric acids and the corresponding acids in which the omega fluorine atom is replaced by hydrogen, together with omega hydro perfluoro pelargonic, undecoic, tridecoic acids, and salts thereof; alpha dihydro perfluoro aliphatic alcohols and amines having from four to twelve carbon atoms and their salts, e.g. hydrochloride, hydrobromide, sulphate or phosphate. The term "alcohol derivative" is defined as a partially fluorinated aliphatic alcohol of formula (i) ROSO3H, (ii) ROSO2X, and (iii) RSO3H and their salts, where X is a metal or ammonium and R is a fluoroalkyl radical containing at least four carbon atoms. Specification 818,519 is referred to.