Casey R P, Njus D, Radda G K, Sehr P A
Biochemistry. 1977 Mar 8;16(5):972-7. doi: 10.1021/bi00624a025.
The hydrogen ion activity within isolated chromaffin granules can be estimated from the distribution of the weak base methylamine and from phosphorus-31 nuclear magnetic resonance spectra of ATP contained in the granules. Following the addition of ATP to the external medium, the internal pH drops by 0.2 to 0.5 unit. This change occurs only in medium containing a permeant anion such as chloride and is abolished by an uncoupler of oxidative phosphorylation. These results indicate that the chromaffin granule membrane possess an electrogenic proton pump directed inward.
可根据弱碱甲胺的分布以及嗜铬颗粒中所含ATP的磷-31核磁共振谱来估算分离出的嗜铬颗粒内的氢离子活性。向外部介质中添加ATP后，内部pH值下降0.2至0.5个单位。这种变化仅发生在含有渗透性阴离子（如氯离子）的介质中，并且会被氧化磷酸化的解偶联剂消除。这些结果表明，嗜铬颗粒膜具有向内的生电质子泵。
