Pfister V R, Homann P H
Arch Biochem Biophys. 1986 May 1;246(2):525-30. doi: 10.1016/0003-9861(86)90307-3.
After an increase in pH of the suspension medium, a pH gradient across the membrane of chloroplast thylakoids stored at pH greater than or equal to 6.5 is often maintained for several minutes. The intrinsic hydrogen ion buffering capacity of the thylakoid membranes between pH 6.5 and 8.5 is about 40 neq/mg chlorophyll, but can be artificially inflated by penetration of the external buffer into the thylakoid vesicle. A delta pH imposed across the thylakoid membrane by an acid/base transition cannot be estimated accurately by the fluorescent probe 9-aminoacridine, especially with osmotically shrunken thylakoids in which 9-aminoacridine appears to become bound or adsorbed to the membrane. This interaction may be related to the existence of the previously demonstrated special pool of slowly equilibrating, "sequestered" protons.
悬浮介质的pH值升高后，储存在pH值大于或等于6.5条件下的叶绿体类囊体膜上的pH梯度通常会维持几分钟。类囊体膜在pH 6.5至8.5之间的固有氢离子缓冲能力约为40纳摩尔当量/毫克叶绿素，但外部缓冲剂渗透到类囊体囊泡中可人为地提高这一能力。通过酸/碱转变在类囊体膜上施加的ΔpH值不能用荧光探针9-氨基吖啶准确估算，特别是对于渗透收缩的类囊体，其中9-氨基吖啶似乎会与膜结合或吸附。这种相互作用可能与先前证明的缓慢平衡的“隔离”质子特殊池的存在有关。
