Abstract:
Polyphenol oxidase (PPO) from
Zyzyphus spina christi
found in central part of Iraq was extracted and
purified by (NH ) SO precipitation, ion-exchange chromatography and gel filtration chromatography.
42 4
The biochemical characteristics reveal that the PPO from
Zyzyphus spina christi
has higher affinity towards
catechol (
K
= 11.4mM and
V
= 16,400 U/ml min
) at an optimum pH of 5.8. The enzyme had an optimum
M
max
1
temperature of 37°C and was relatively stable up to 50°C for a period of 60 minutes with almost 80% activity
remaining. Among the various PPO inhibitors tested, the most effective inhibitor for the enzyme with 10mM
catechol as substrate was ascorbic acid
