Ivkova M N, Pechatnikov V A, Ivkov V G, Pletnev V V
Biofizika. 1983 Jan-Feb;28(1):160-70.
A method for estimation of constants of carbocyanine probe diS-C3-(5) partition between water and membrane phases was developed based on the analysis of fluorometric titration curves. The partition constants (K) of this dye were calculated (the ratio of dye mole fraction in membrane and water phases) for sarcoplasmic reticulum (SR) vesicles in sucrose K = (1.15 +/- 0.04) X 10(7) and salt K = (6.12 +/- 0.07) X 10(6) media and for the asolectine liposomes in salt medium K = (3.4 +/- 0.2) X 10(7). The probe partition between water and lipid phases was calculated for different membrane concentrations. Critical aggregation concentrations of probe in lipid phase were estimated to be approximately 8 mol. probe per 1000 mol. lipid for asolectine liposomes and approximately 9 mol. per 1000 mol. lipid for SR vesicles (both in salt medium), approximately 6 mol. per 1000 mol. lipid for SR vesicles in sucrose medium. On the basis of own and literature data a mechanism of voltage-sensitive probe response related to probe aggregation in membranes was suggested.
基于对荧光滴定曲线的分析，开发了一种估算碳菁探针二磺酸 - C3 - (5) 在水相和膜相之间分配常数的方法。计算了该染料在蔗糖介质中肌浆网（SR）囊泡的分配常数（K）（膜相和水相中染料摩尔分数之比），K = (1.15 ± 0.04) × 10⁷，在盐介质中K = (6.12 ± 0.07) × 10⁶；还计算了在盐介质中大豆卵磷脂脂质体的分配常数K = (3.4 ± 0.2) × 10⁷。针对不同的膜浓度计算了探针在水相和脂质相之间的分配情况。估计在脂质相中探针的临界聚集浓度，对于大豆卵磷脂脂质体约为每1000摩尔脂质中有8摩尔探针，对于SR囊泡（均在盐介质中）约为每1000摩尔脂质中有9摩尔探针，对于蔗糖介质中的SR囊泡约为每1000摩尔脂质中有6摩尔探针。基于自身及文献数据，提出了与膜中探针聚集相关的电压敏感探针响应机制。
