Smith G P, Peters T J
Eur J Clin Invest. 1980 Dec;10(6):475-80. doi: 10.1111/j.1365-2362.1980.tb02088.x.
Magnesium-dependent adenosine triphosphatase (Mg2+-ATPase) activities wee studied in human neutrophilic polymorphonuclear leucocytes. Kinetic studies on whole leucocyte homogenates produced curvilinear kinetics suggesting the presence of at least two forms of Mg2+-ATPase. Neutrophils were homogenized in isotonic sucrose and, after low-speed centrifugation, the supernatant was subjected to analytical subcellular fractionation. Gradient fractions were assayed for Mg2+-ATPase and for principal organelle marker enzymes. Mg2+-ATPase was distributed between the plasma membrane, mitochondrial and cytosol fractions. Kinetic and inhibitor studies on Mg2+-ATPase from each localization indicated the presence of three forms of the enzyme. The plasma membrane and mitochondrial activities had a Km value of 0.2 mmol/l for ATP, whilst the Km for the cytosolic enzyme was 1.8 mmol/l. Inhibitor studies showed further differences between the three enzymes. Neutrophils were isolated from control subjects, patients with chronic granulocytic leukaemia and patients in the third trimester of pregnancy. The specific activities (mUnits/mg protein) of Mg2+-ATPase, in contrast to those of alkaline phosphatase, were similar in all three patient groups. This result, together with the fractionation experiments and inhibitor studies, strongly suggest that the ATPase is not attributable to neutrophil alkaline phosphatase.
对人嗜中性多形核白细胞中的镁依赖性腺苷三磷酸酶（Mg2 + -ATP酶）活性进行了研究。对全白细胞匀浆的动力学研究产生了曲线动力学，表明至少存在两种形式的Mg2 + -ATP酶。将嗜中性粒细胞在等渗蔗糖中匀浆，低速离心后，将上清液进行亚细胞分级分析。对梯度级分进行Mg2 + -ATP酶和主要细胞器标记酶的测定。Mg2 + -ATP酶分布在质膜、线粒体和胞质溶胶级分之间。对来自每个定位的Mg2 + -ATP酶的动力学和抑制剂研究表明存在三种形式的该酶。质膜和线粒体活性的ATP Km值为0.2 mmol/l，而胞质酶的Km值为1.8 mmol/l。抑制剂研究显示这三种酶之间存在进一步差异。从对照受试者、慢性粒细胞白血病患者和妊娠晚期患者中分离出嗜中性粒细胞。与碱性磷酸酶相比，Mg2 + -ATP酶的比活性（m单位/毫克蛋白质）在所有三个患者组中相似。这一结果，连同分级实验和抑制剂研究，强烈表明该ATP酶并非源自嗜中性粒细胞碱性磷酸酶。
