Siezen R J, Owen E A
Biophys Chem. 1983 Oct;18(3):181-94. doi: 10.1016/0301-4622(83)80030-1.
Concentrated solutions of calf alpha-crystallin (up to 45 g/l) and gamma-crystallin (up to 67 g/l) were subjected to frontal exclusion chromatography at pH 7.3, ionic strength 0.17 and 20 degrees C. The experimental concentration dependence of the weight-average partition coefficient was compared with theoretical expressions, which include considerations of thermodynamic non-ideality effects, for the concentration dependence of a single solute and of a solute undergoing reversible self-association. Two types of association pattern were examined, discrete dimerization and indefinite self-association. The partition chromatography results are consistent with an indefinite self-association of gamma-crystallin, governed by an isodesmic association constant of 6.7 X 10(-3) l/g. alpha-Crystallin appears to self-associate either very weakly, with a maximal association constant of 0.9 X 10(-3) l/g, or not at all; the distinction depends on the assessment of the non-ideality coefficients. The consequences of excluded volume effects on these self-association equilibria at high total protein concentration are discussed. Mixtures of alpha-crystallin and gamma-crystallin were analyzed by frontal exclusion chromatography (up to 14 g/l) and sedimentation velocity (up to 115 g/l): no interaction was observed.
将小牛α-晶状体蛋白（浓度高达45 g/l）和γ-晶状体蛋白（浓度高达67 g/l）的浓缩溶液在pH 7.3、离子强度0.17和20℃条件下进行前沿排阻色谱分析。将重均分配系数的实验浓度依赖性与理论表达式进行比较，这些理论表达式包括对单一溶质以及发生可逆自缔合溶质的浓度依赖性的热力学非理想效应的考虑。研究了两种缔合模式，即离散二聚化和不定自缔合。分配色谱结果与γ-晶状体蛋白的不定自缔合一致，其受等键缔合常数6.7×10⁻³ l/g控制。α-晶状体蛋白似乎要么自缔合非常弱，最大缔合常数为0.9×10⁻³ l/g，要么根本不自缔合；这种区别取决于对非理想系数的评估。讨论了在高总蛋白浓度下排阻体积效应对这些自缔合平衡的影响。通过前沿排阻色谱（浓度高达14 g/l）和沉降速度（浓度高达115 g/l）对α-晶状体蛋白和γ-晶状体蛋白的混合物进行分析：未观察到相互作用。
