Mollinedo F, Manara F S, Schneider D L
J Biol Chem. 1986 Jan 25;261(3):1077-82.
The acidification activity of human neutrophils, known to occur extracellularly and intraphagolysosomally, was studied in intact and in fractionated cells. The subcellular location of the acidification activity was investigated by rate zonal sedimentation of post-nuclear supernatants from resting cells on continuous sucrose gradients. The acidification measurements indicated a dominance of activity in gelatinase-rich tertiary granules. On the other hand, ATPase activities were located in plasma membrane and in the membranes of the cytoplasmic granules (specific, azurophilic, and tertiary). All of these activities were diminished by the inhibitors dicyclohexylcarbodiimide and diisothiocyanostilbene disulfonic acid; however, studies with other inhibitors, especially N-ethylmaleimide and duramycin, suggested ATPase enzymatic differences depending on location. The results taken together provide direct and strong indication of involvement of a proton pump ATPase in acidification inside neutrophils. Furthermore, the dominant location of acidification activity in tertiary granules that very readily degranulate presumably has significant implications for the importance of low pH in cidal events and the inflammatory process.
已知人类中性粒细胞的酸化活性发生在细胞外和吞噬溶酶体内，我们对完整细胞和分离细胞中的这种活性进行了研究。通过在连续蔗糖梯度上对静息细胞的核后上清液进行速率区带沉降，研究了酸化活性的亚细胞定位。酸化测量表明，富含明胶酶的三级颗粒中活性占主导地位。另一方面，ATP酶活性位于质膜和细胞质颗粒（特异性、嗜天青和三级）的膜中。所有这些活性都被二环己基碳二亚胺和二异硫氰酸芪二磺酸抑制剂所降低；然而，使用其他抑制剂，特别是N - 乙基马来酰亚胺和短杆菌肽的研究表明，ATP酶的酶活性因位置而异。综合这些结果提供了直接且有力的证据，表明质子泵ATP酶参与了中性粒细胞内的酸化过程。此外，酸化活性在极易脱颗粒的三级颗粒中的主要定位，可能对低pH值在杀菌事件和炎症过程中的重要性具有重要意义。
