The effects of N,N′-dicyclohexylcarbodiimide (DCCD), non-specific inhibitor of various transport systems functioning in biological membranes, on Na+-transporting P-type ATPase of the green halotolerant microalga Dunaliella maritima were studied in the experiments with vesicular plasma membranes isolated from the alga cells. The effects of DCCD on electrogenic/ion transport function of the enzyme and its ATP hydrolase activity were investigated. Electrogenic/ion transport function of the enzyme was recorded as a Na+-dependent generation of electric potential on the vesicle membranes with the help of the potential-sensitive probe oxonol VI. It was found that unlike many other ion-transporting ATPases, the Na+-ATPase of D. maritima is insensitive to DCCD. This agent did not inhibit either ATP hydrolysis catalyzed by this enzyme or its transport activity. At the same time DCCD affected the ability of the vesicle membranes to maintain electric potential generated by the D. maritima Na+-ATPase. The observed effects can be explained based on the assumption that DCCD interacts with the Na+/H+ antiporter in the plasma membrane of D. maritima.

中文翻译：

---

耐盐微藻Dunaliella maritima 质膜组分的电生作用及N,N'-二环己基碳二亚胺的影响

在囊泡质膜实验中研究了 N,N'-二环己基碳二亚胺 (DCCD)，生物膜中各种转运系统的非特异性抑制剂，对绿色耐盐微藻 Dunaliella maritima 的 Na+-转运 P 型 ATP 酶的影响从藻细胞中分离。研究了DCCD对酶的生电/离子转运功能及其ATP水解酶活性的影响。在电位敏感探针 oxonol VI 的帮助下，酶的生电/离子传输功能被记录为囊泡膜上 Na+ 依赖性产生的电位。发现与许多其他离子传输 ATPases 不同，D. maritima 的 Na+-ATPase 对 DCCD 不敏感。该试剂不抑制由该酶催化的 ATP 水解或其转运活性。同时，DCCD 影响囊泡膜维持由海藻 Na+-ATPase 产生的电势的能力。观察到的效果可以基于 DCCD 与 D. maritima 质膜中的 Na+/H+ 逆向转运蛋白相互作用的假设来解释。