Behlke J, Labudde D, Ristau O
Max Delbrück Center for Molecular Medicine, Berlin, Germany.
Eur Biophys J. 2001 Oct;30(6):411-5. doi: 10.1007/s002490100164.
The self-association behavior of the Eph-kinases SAM domain has been studied in phosphate buffer, pH 7.4, containing 0.14 M NaCl using concentration-dependent sedimentation equilibrium experiments. Only weak interactions typical for a monomer-dimer equilibrium up to at least 12 mg/mL were observed. Such concentrated solutions require a consideration of the non-ideality expressed by virial coefficients. A special centrifuge equation was used for the global analysis to estimate equilibrium constants based on the thermodynamic activities of the reactants. When neglecting this, the parameters deviate by about 20%. Association constants for dimerization of the EphB2-SAM domain vary between 163 M(-1) at 10 degrees C and 395 M(-1) at 32 degrees C, indicating hydrophobic forces are involved in the dimerization process. In solutions of about 12 mg/mL, less than 50% dimers are in solution and higher oligomers can be excluded.
利用浓度依赖性沉降平衡实验，在含有0.14 M NaCl、pH 7.4的磷酸盐缓冲液中研究了Eph激酶SAM结构域的自缔合行为。直至至少12 mg/mL，仅观察到单体 - 二聚体平衡典型的弱相互作用。如此高浓度的溶液需要考虑维里系数所表示的非理想性。使用特殊的离心机方程进行全局分析，以基于反应物的热力学活性估算平衡常数。若忽略此点，参数偏差约20%。EphB2 - SAM结构域二聚化的缔合常数在10℃时为163 M⁻¹，在32℃时为395 M⁻¹，表明疏水作用力参与了二聚化过程。在约12 mg/mL的溶液中，溶液中二聚体含量不到50%，且可排除更高的寡聚体。
