들깨잎 polyphenol oxidase의 세포내 분포 및 특성

Subcellular Distributin and Characteristics of Polyphenol Oxidase from Perilla frutescens Leaves

Polyphenol oxidase (PPO) activity in 200Xg (cell wall), 4,000Xg (plastid), 100,000Xg (mitochondrial) and soluble fractions of the perilla leaves was monitored in the upper, middle and lower sections of the plant. In the course of plant growth, PPO activities in plastid and mitochondrial fractions were decreased, while those in cell wall fraction were maintained. During growing process, specific activities and PPO activities of each fraction were decreased, while total phenol content were decreased in middle (middle) and then increased in later stage (lower). Cell wall, plastid, mitochondrial (pellet) and soluble fraction had slightly different pH optima and substrate specificities. Isoenzyme patterns were identical in two bands for PPO activity in different subsellular fractions. Their molecular weight were 37KD and 48KD respectively.