Purification of proteins with cationic surfactant

摘要

The subject invention provides a method for purifying a target protein from a mixture comprising the target protein and contaminating protein, comprising the steps of exposing the mixture to an effective amount of a cationic surfactant such that the contaminating protein is preferentially precipitated and recovering the target protein. Proteins purified according to the method of the invention are also provided.

主权项

1. A method for purifying a uricase comprising:
a. obtaining a solution comprising a mixture of a solubilized uricase, one or more solubilized contaminating proteins and an alkaline buffer, wherein the uricase is positively charged under alkaline pH and has an isoelectric point greater than 7 and the one or more contaminating proteins has a polyanion charge; b. contacting the solution comprising the mixture of the solubilized uricase and the one or more solubilized contaminating proteins with one or more cationic surfactants in an amount effective to preferentially precipitate the one or more contaminating proteins, thereby increasing the proportion of proteins remaining in solution represented by the uricase; and c. recovering the uricase in solution after the preferential precipitation of step b; wherein the method is performed in the absence of a solid support and wherein the one or more cationic surfactants is an amphipathic ammonium compound selected from the group consisting of a quaternary ammonium compound of the general formula QN+; a paraffin chain primary ammonium compound of the general formula RNH3+; and a salt thereof.