The effect of some heavy metals on the kinetic parameters of the enzyme polyphenol oxidase in different crude plant extracts

مقدم أطروحة جامعية

al-Dalaiin, Lujain Ata Allah Ali

مشرف أطروحة جامعية

Atruz, Umar

أعضاء اللجنة

al-Tarawinah, Khalid
al-Rawashidah, Ibrahim Muhammad
al-Mustafa, Ahmad Husayn Husayn

الجامعة

جامعة مؤتة

الكلية

كلية العلوم

القسم الأكاديمي

قسم الأحياء

دولة الجامعة

الأردن

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2016

الملخص الإنجليزي

Polyphenol oxidases (PPOs) activity from Camellia sinensis, Olea europaea, Salvia officnalis and Thymus vulgaris were studied .

The present study was undertaken to obtain crude PPO extract from these plants and to characterize it in terms of pH, temperature, enzyme kinetic, browning and heavy metals effects on its activity was studied .

Camellia sinensis showed the highest browning intensity when compared to the other plants and Olea europaea showed the lowest.

The results indicated that the highest activity for PPO was found in Camellia sinensis (Vmax= 0.586 µmol/min).Whereas, the least value was in Olea europaea ( Vmax= 0.045 µmol/min ) at pH 6 and temprture (40°C).

The study of the effects of some heavy metals on PPO activity indicated that the PPO activity in Salvia officnalis was increased in presence of 400µM of Ni2+, Al3+, Cd2+, Cu2+, Pb2+, Fe3+, Co2+and Zn2+ as Uncompetitive inhibition.

Hg2+ and Cr2+acted as noncompetitive inhibitor in crude Salvia officnalis While Al3+, Zn2+, Pb2+, Cd2+, Mo2+ and Cr2+ for crude enzyme PPO extracts of Camellia sinensis and in Olea europaea act as Uncompetitive inhibition .

while, the presence of Co2+ increases the activity in the crude extract of Salvia officinalis and it exhibited as an noncompetitive inhibition in Camellia sinensis and uncompetitive inhibition in Thymus vulgaris and Olea europaea .

High correlation was found between the enzymatic browning and PPO activity which supports the hypothesis that PPO was responsible for brown discoloration .

التخصصات الرئيسية

الأحياء

عدد الصفحات

45

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-731528