AFFINITY PURIFICATION AND PROPERTIES OF POLYPHENOLOXIDASE FROM SOLANUM-TUBEROSUM

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.