The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by th...The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by the plasma membrane H +_ATPase were studied. The results showed that the proton transport activity was increased by 850% in the presence of 100 mmol/L KCl, while ATP hydrolytic activity was only increased by 28.2%. Kinetic studies showed that K m of ATP hydrolysis decreased from 1.14 to 0.7 mmol/L, while V max of ATP hydrolysis increased from 285.7 to 344.8 nmol Pi·mg -1 protein·min -1 in the presence of KCl. Experiments showed that the optimum pH was 6.5 and 6.0 in the presence and absence of KCl, respectively. Further studies revealed that K + could promote the inhibitory effects of hydroxylamines and vanadates on the ATP hydrolytic activity. The above results suggested that K + could regulate the coupling between ATP hydrolysis and proton transport of the plasma membrane H +_ATPase through modulating the structure and function of the kinase and phosphatase domains of the plasma membrane H +_ATPase.展开更多
Studies on the thermokinetic properties of model compound of Purple acid phosphatases (Na2[Fe2(μ-O)(μ-OAC)2(IDA)2].5H2O hydrolysis of ATP, at 37℃, pH=6.0 by usingLKB-2107 Batch microcalorimentry system. The Michael...Studies on the thermokinetic properties of model compound of Purple acid phosphatases (Na2[Fe2(μ-O)(μ-OAC)2(IDA)2].5H2O hydrolysis of ATP, at 37℃, pH=6.0 by usingLKB-2107 Batch microcalorimentry system. The Michaelis constant Km=(2.898 ± 0.195)x 10-4mol.L-1 and rate constant k2=(4.617±0.193) x 10-3.s-1 have been determined. The result hasbeen discussed.展开更多
文摘The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by the plasma membrane H +_ATPase were studied. The results showed that the proton transport activity was increased by 850% in the presence of 100 mmol/L KCl, while ATP hydrolytic activity was only increased by 28.2%. Kinetic studies showed that K m of ATP hydrolysis decreased from 1.14 to 0.7 mmol/L, while V max of ATP hydrolysis increased from 285.7 to 344.8 nmol Pi·mg -1 protein·min -1 in the presence of KCl. Experiments showed that the optimum pH was 6.5 and 6.0 in the presence and absence of KCl, respectively. Further studies revealed that K + could promote the inhibitory effects of hydroxylamines and vanadates on the ATP hydrolytic activity. The above results suggested that K + could regulate the coupling between ATP hydrolysis and proton transport of the plasma membrane H +_ATPase through modulating the structure and function of the kinase and phosphatase domains of the plasma membrane H +_ATPase.
文摘Studies on the thermokinetic properties of model compound of Purple acid phosphatases (Na2[Fe2(μ-O)(μ-OAC)2(IDA)2].5H2O hydrolysis of ATP, at 37℃, pH=6.0 by usingLKB-2107 Batch microcalorimentry system. The Michaelis constant Km=(2.898 ± 0.195)x 10-4mol.L-1 and rate constant k2=(4.617±0.193) x 10-3.s-1 have been determined. The result hasbeen discussed.
文摘基于核酸适体对靶标的特异性识别和辣根过氧化物酶（HRP）的高效催化反应,发展了一种用于检测三磷酸腺苷（ATP）的酶联核酸适体分析新方法.核酸适体和靶标的特异性结合导致与核酸适体杂交的短链DNA 解链,解离的 DNA 通过杂交被固定在另一酶标板的 DNA 捕获.解离的 DNA 预先标记了异硫氰酸荧光素（FITC）基团, FITC 特异性结合 HRP 标记的 FITC 抗体, HRP 作为信号传导元素催化四甲基二苯胺（TMB）底物显色,通过颜色变化及450 nm 波长处吸光度的变化检测 ATP.该方法对 ATP 具有良好的选择性,检测不受其它物质如 GTP, UTP 和 CTP 的干扰,且检测能在较复杂的试样（体积分数10%和50%的血清）中进行.实验结果表明,在 ATP 浓度为50~400 nmol/ L 范围内,具有良好的线性关系,检出限为26 nmol/ L.
