Objective: To explore the possible inhibitory potentials and mechanism by Mobola plum(Parinari curatellifolia) seeds crude methanol(CE) and flavonoid-rich(FE) extracts on angiotensin-1-converting enzyme(ACE Ⅰ).Method...Objective: To explore the possible inhibitory potentials and mechanism by Mobola plum(Parinari curatellifolia) seeds crude methanol(CE) and flavonoid-rich(FE) extracts on angiotensin-1-converting enzyme(ACE Ⅰ).Methods: The sensitivity and kinetic model of inhibition of CE and FE on ACE Ⅰ using N-[3-(2-furyl)-acryloyl]-Phe-Gly-Gly as enzyme substrate for ACE Ⅰ was evaluated by Michealis Menten approach. The inhibition mechanism was explored from Lineweaver–Burk model and IC_(50) was determined from Cheng–Prusoff empirical analysis.Results: The IC_(50) of CE and FE were 13.54 and 39.38 mg/m L, respectively. Both extracts exhibited mixed type inhibition with the inhibitory constant(K_i) of CE was between0.38 and 0.37 mg/m L while that of FE showed a two-fold increase(1.62 mg/mL and0.28 mg/mL). FE on ACE Ⅰ demonstrated positive cooperativity with a Hill's coefficient of1.89.Conclusions: The study reveals the superior ACE Ⅰ inhibitory potential of CE over FE and suggest that mixed inhibition pattern of the enzyme might be the underlying mechanism of antihypertensive activity.展开更多
Kinetic experiments were performed to study the effects of Pd2+ ion on the oxidation of 5,6-dibro-mo-2,3-dicyanohydroquinone catalyzed by Rhus vernicifera laccase under condition of pH 4.5 and 30 × 0. 1℃ . The r...Kinetic experiments were performed to study the effects of Pd2+ ion on the oxidation of 5,6-dibro-mo-2,3-dicyanohydroquinone catalyzed by Rhus vernicifera laccase under condition of pH 4.5 and 30 × 0. 1℃ . The results showed that the mixed activation could be observed when Pd2+ ion was at low concentrations. The competitive and non-competitive activation constants were 9 × 10 and 2 × 10-6 mol/L, respectively. With the increase of Pd2+ ion concentration, the activation was gradually converted into mixed inhibition, and the competitive and non-competitive inhibition constants were 6 × 10-6 and 32 × 10-6 mol/L, respectively.展开更多
文摘Objective: To explore the possible inhibitory potentials and mechanism by Mobola plum(Parinari curatellifolia) seeds crude methanol(CE) and flavonoid-rich(FE) extracts on angiotensin-1-converting enzyme(ACE Ⅰ).Methods: The sensitivity and kinetic model of inhibition of CE and FE on ACE Ⅰ using N-[3-(2-furyl)-acryloyl]-Phe-Gly-Gly as enzyme substrate for ACE Ⅰ was evaluated by Michealis Menten approach. The inhibition mechanism was explored from Lineweaver–Burk model and IC_(50) was determined from Cheng–Prusoff empirical analysis.Results: The IC_(50) of CE and FE were 13.54 and 39.38 mg/m L, respectively. Both extracts exhibited mixed type inhibition with the inhibitory constant(K_i) of CE was between0.38 and 0.37 mg/m L while that of FE showed a two-fold increase(1.62 mg/mL and0.28 mg/mL). FE on ACE Ⅰ demonstrated positive cooperativity with a Hill's coefficient of1.89.Conclusions: The study reveals the superior ACE Ⅰ inhibitory potential of CE over FE and suggest that mixed inhibition pattern of the enzyme might be the underlying mechanism of antihypertensive activity.
基金Natural Science Foundation of Guangxi (No.9743018)
文摘Kinetic experiments were performed to study the effects of Pd2+ ion on the oxidation of 5,6-dibro-mo-2,3-dicyanohydroquinone catalyzed by Rhus vernicifera laccase under condition of pH 4.5 and 30 × 0. 1℃ . The results showed that the mixed activation could be observed when Pd2+ ion was at low concentrations. The competitive and non-competitive activation constants were 9 × 10 and 2 × 10-6 mol/L, respectively. With the increase of Pd2+ ion concentration, the activation was gradually converted into mixed inhibition, and the competitive and non-competitive inhibition constants were 6 × 10-6 and 32 × 10-6 mol/L, respectively.
