Schüler J, Frank J, Saenger W, Georgalis Y
Institut für Kristallographie, Freie Universität Berlin, D-14195 Berlin, Germany.
Biophys J. 1999 Aug;77(2):1117-25. doi: 10.1016/S0006-3495(99)76962-6.
The thermal stability of transferrin receptor isolated from human placenta in detergent-free solution has been investigated by static light-scattering and photon correlation spectroscopy. In detergent-free solution at 293.2 K, human transferrin receptor (hTfR) forms stable associates with a hydrodynamic radius of 16 nm. With increasing temperature the particles get more compact, above 340 K a phase transition takes, place and spontaneous aggregation of the receptor occurs. Under these conditions large clusters are formed that lead to fractal aggregates, coexisting with dendritic crystalline structures. The experimental findings are compatible with a model, which involves a reaction limited cluster-cluster aggregation mechanism in conjunction with a nucleation process. The molar enthalpy change associated with the phase transition was determined to be (1860 +/- 150) kJ/mol(-1) at a transition temperature of (341.3 +/- 0.2) K.
通过静态光散射和光子相关光谱法研究了从人胎盘中分离出的转铁蛋白受体在无洗涤剂溶液中的热稳定性。在293.2 K的无洗涤剂溶液中，人转铁蛋白受体（hTfR）形成了稳定的缔合体，其流体动力学半径为16 nm。随着温度升高，颗粒变得更加致密，在340 K以上发生相变，受体发生自发聚集。在这些条件下会形成大的聚集体，导致分形聚集体，并与树枝状晶体结构共存。实验结果与一个模型相符，该模型涉及反应受限的簇-簇聚集机制以及成核过程。在转变温度（341.3±0.2）K下，与相变相关的摩尔焓变为（1860±150）kJ/mol⁻¹。
