Romano-Fontes L G, Curi R, Peres C M, Nishiyama-Naruke A, Brunaldi K, Abdulkader F, Procopio J
Departamento de Fisiologia e Biofísica, Instituto de Ciencias Biomédicas, Universidade de São Paulo, Brazil.
Lipids. 2000 Jan;35(1):31-4. doi: 10.1007/s11745-000-0491-4.
The transport of palmitic acid (PA) across planar lipid bilayer membranes was measured using a high specific activity [14C]palmitate as tracer for PA. An all-glass trans chamber was employed in order to minimize adsorbance of PA onto the surface. Electrically neutral (diphytanoyl phosphatidylcholine) and charged (Azolectin) planar bilayers were maintained at open electric circuit. We found a permeability to PA of (8.8 +/- 1.9) x 10(-6) cm s(-1) (n = 15) in neutral and of (10.3 +/- 2.2) x 10(-6) cm s(-1) (n = 5) in charged bilayers. These values fall within the order of magnitude of those calculated from desorption constants of PA in different vesicular systems. Differences between data obtained from planar and vesicular systems are discussed in terms of the role of solvent, radius of curvature, and pH changes.
使用高比活度的[14C]棕榈酸盐作为棕榈酸（PA）的示踪剂，测量了PA跨平面脂质双分子层膜的转运。采用全玻璃传输室以尽量减少PA在表面的吸附。电中性（二植烷酰磷脂酰胆碱）和带电（大豆卵磷脂）平面双分子层保持在开路状态。我们发现，在中性双分子层中PA的渗透率为(8.8±1.9)×10(-6) cm s(-1)（n = 15），在带电双分子层中为(10.3±2.2)×10(-6) cm s(-1)（n = 5）。这些值在根据PA在不同囊泡系统中的解吸常数计算出的值的数量级范围内。从平面和囊泡系统获得的数据差异根据溶剂的作用、曲率半径和pH变化进行了讨论。
