【摘要】 NO可以通过其辅因子氧化灭活作用抑制ACC氧化酶(ACO)活性,从而降低乙烯释放速率。本文主要研究了NO对ACO抑制作用的化学动力学,揭示了NO对ACO活性的抑制机理。NO溶液与ACC氧化酶的最佳反应时间是30min,底物ACC的最佳浓度为2mmol/L,作为酶促反应的辅因子,抗坏血酸钠和Fe2+的最适浓度分别为60mmol/L和60μmol/L,碳酸氢钠的最适浓度为60mmol/L。Lineweaver-Burk图显示NO是一种非竞争性抑制剂。NO与ACO反应的米氏常数Km为2.54mmol/L,抑制常数Ki为3.22μmol/L。更多还原

【Abstract】 NO can restrain the activity of ACO via the inactivate oxidation of NO ’s cofactor,resulting in reduction of ethylene producing rate. This paper mainly studied the inhibition kinetics of NO on ACO activity and revealed the inhibition mechanism of NO on ACO activity. The optimum reaction time between NO and ACO and the concentration of ACC were 30 min and 2 mmol / L,respectively. As cofactors of the enzyme reaction,the suitable concentrations of Vc,Na HCO3 and Fe2 +were 60 mmol / L,60 mmol / L and 60μmol / L respectively. The inhibition kinetics of NO analyzed by Lineweaver-Burk plots demonstrated that the inhibition effect of NO on the oxidation of ACO was a noncompetitive inhibition. The apparent Michaelis constant Kmand the inhibition constant of noncompetitive reversible inhibitor Kiwere determined to be 2. 54 mmol / L and 3. 22μmol / L respectively.更多还原