Borregaard N, Boxer L A, Smolen J E, Tauber A I
Am J Hematol. 1985 Mar;18(3):255-60. doi: 10.1002/ajh.2830180306.
Neutrophils from a patient with lactoferrin deficiency were examined and the quantity and subcellular localization of protein markers were determined on Percoll density gradients. Distribution of azurophilic and specific granule markers was abnormal in that azurophilic granules were lighter than normal and appeared in the fraction of the gradient where normally the specific granules sediment. The specific granule membrane markers, cytochrome b-235 and its associated flavoprotein, were abnormally distributed in the gamma fraction, the site of the plasma membrane marker alkaline phosphatase. Thus, the b-cytochrome-flavoprotein complex had either been incorporated into the plasma membrane or was still present in the membranes of granules that were abnormally light and cosedimented with the plasma membranes. This is of particular interest in regard to the patient's respiratory burst oxidase function, since the b-cytochrome/flavoprotein complex normally translocates from the specific granules to the plasma membrane to constitute the active respiratory burst oxidase. The functional consequences of this abnormal distribution are discussed, as is the importance of characterizing both intragranular enzymatic markers and granule membrane proteins to define granular disorders.
对一名乳铁蛋白缺乏患者的中性粒细胞进行了检查，并在Percoll密度梯度上测定了蛋白质标志物的数量和亚细胞定位。嗜天青颗粒和特异性颗粒标志物的分布异常，表现为嗜天青颗粒比正常情况下轻，并出现在梯度中通常特异性颗粒沉降的部分。特异性颗粒膜标志物细胞色素b-235及其相关黄素蛋白在γ部分异常分布，γ部分是质膜标志物碱性磷酸酶所在的位置。因此，b-细胞色素-黄素蛋白复合物要么已整合到质膜中，要么仍存在于异常轻且与质膜共沉降的颗粒膜中。这对于患者的呼吸爆发氧化酶功能特别有意义，因为b-细胞色素/黄素蛋白复合物通常从特异性颗粒转移到质膜以构成活性呼吸爆发氧化酶。本文讨论了这种异常分布的功能后果，以及表征颗粒内酶标志物和颗粒膜蛋白以定义颗粒疾病的重要性。
