Phenylalanine Ammonia-lyase of Bamboo Shoots

Abstract

Phenylalanine ammonia-lyase (PAL) was purified from bamboo shoots (Bambusa oldhami Munro) through steps of DEAE-Sephacel column chromatography, Sepharose CL-6B gel filtration, and a second DEAE-Sephacel column chromatography. Polyacrylamide gel electrophoresis showed that the purified enzyme (M_r 360,000) still contained two minor bands with much slower mobilities (M_r ≥ 660,000) than the major one. The minor band could be the aggregated forms of native PAL, based on the fact that only a single band (M_r 86,000) was observed upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis or isoelectric focusing, and all bands shared common antigenic determinants as revealed by immunoblotting done with an antiserum raised against the major band. There was a sharp rise of PAL activity of bamboo shoots after harvest, and this was only partly due to the de novo synthesis of this enzyme as measured by Laurell’s rocket immunoelectrophoresis.