Lockridge_2018_J.Chromatogr.B.Analyt.Technol.Biomed.Life.Sci_1102-1103_109

Affinity chromatography on procainamide-Sepharose has been an important step in the purification of butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) since its introduction in 1978. The procainamide affinity gel has limitations. In the present report a new affinity gel called Hupresin(R) was evaluated for its ability to purify truncated, recombinant human butyrylcholinesterase (rHuBChE) expressed in a stably transfected Chinese Hamster Ovary cell line. We present a detailed example of the purification of rHuBChE secreted into 3940mL of serum-free culture medium. The starting material contained 13,163units of BChE activity (20.9mg). rHuBChE was purified to homogeneity in a single step by passage over 82mL of Hupresin(R) eluted with 0.1M tetramethylammonium bromide in 20mM TrisCl pH7.5. The fraction with the highest specific activity of 630units/mg contained 11mg of BChE. Hupresin(R) is superior to procainamide-Sepharose for purification of BChE, but is not suitable for purifying native AChE because Hupresin(R) binds AChE so tightly that AChE is not released with buffers, but is desorbed with denaturing solvents such as 50% acetonitrile or 1% trifluoroacetic acid. Procainamide-Sepharose will continue to be useful for purification of AChE.