Barnes E M
J Bacteriol. 1980 Aug;143(2):1086-9. doi: 10.1128/jb.143.2.1086-1089.1980.
Addition of ionophores to resting aerobic cultures of Azotobacter vinelandii OP resulted in 45Ca2+ uptake (Km = 60 microM Ca2+; Vmax 1.1 nmol/min per mg of cell protein) which was inhibited by cations (La3+ greater than Mn2+ greater than Sr2+ greater Ba2+). The rate of Ca2+ entry correlated with the magnitude of a transmembrane proton gradient (inside acid) which developed in the respective order: valinomycin less than tetrachlorosalicylanilide less than nigericin less than gramicidin D less than tetrachlorosalicylanilide plus valinomycin. A process of calcium-proton exchange (antiport) is responsible for calcium accumulation under these conditions.
向多粘芽孢杆菌OP的静止需氧培养物中添加离子载体导致45Ca2+摄取（Km = 60 microM Ca2+；Vmax为每毫克细胞蛋白1.1 nmol/分钟），该摄取受到阳离子抑制（La3+ > Mn2+ > Sr2+ > Ba2+）。Ca2+进入速率与跨膜质子梯度（内部呈酸性）的大小相关，其形成顺序为：缬氨霉素 < 四氯水杨苯胺 < 尼日利亚菌素 < 短杆菌肽D < 四氯水杨苯胺加缬氨霉素。在这些条件下，钙-质子交换（反向转运）过程负责钙的积累。
