Polyphenoloxidase from potato tuber was purified to homogeneity in a s
ingle step by affinity chromatography using p-aminophenyl acetic acid
as a ligand coupled to Sepharose 4B by the divinylsulphone activation
method. The purified enzyme was homogeneous on native and SDS-PAGE, in
dicating the absence of multiple forms of the enzyme. Spectroscopic st
udies of the purified enzyme indicated a peak at 275 nm and a broad sh
oulder in the region between 320 and 340 nm, which is a characteristic
of a purified preparation. The M(r) was 60 x 10(3). The kinetics of t
he purified enzyme were studied.