Shahid F, Gomez J E, Birnbaum E R, Darnall D W
J Biol Chem. 1982 May 25;257(10):5618-22.
Serum albumin exists in the native or N conformation between pH 5 and 7. As the pH is lowered from 5 to 3.5, the protein undergoes a conformational change resulting in expansion, known as the N = to F (partially acid expanded) transition. As the pH is lowered still further to 2, the protein continues to expand. In the present study, using the techniques of circular dichroism, fluorescence, and UV difference spectroscopy, lanthanide ions at concentrations between 1-30 mM have been shown to produce both changes in the albumin structure analogous to the N = to F transition and acid expansion of bovine serum albumin at a constant pH near 6.
血清白蛋白在pH值为5至7之间以天然或N构象存在。当pH值从5降至3.5时，蛋白质会发生构象变化，导致膨胀，这被称为N转变为F（部分酸膨胀）转变。当pH值进一步降至2时，蛋白质会继续膨胀。在本研究中，使用圆二色性、荧光和紫外差光谱技术，已表明浓度在1 - 30 mM之间的镧系离子会在接近6的恒定pH值下使白蛋白结构发生类似于N转变为F转变的变化以及牛血清白蛋白的酸膨胀。
