Distinguishing the monomer to cluster phase transition in concentrated lysozyme solutions by studying the temperature dependence of the short-time dynamics
Distinguishing the monomer to cluster phase transition in concentrated lysozyme solutions by studying the temperature dependence of the short-time dynamics
复制标题
DOI：
10.1088/0953-8984/24/6/064114
复制
发表时间：
2012-02-15
影响因子：
2.7
通讯作者：
Liu, Yun
中科院分区：
文献类型：
--
作者：
Falus, Peter;Porcar, Lionel;Liu, Yun
Recent combined experiments by small angle neutron scattering (SANS) and neutron spin echo (NSE) have demonstrated that dynamic clusters can form in concentrated lysozyme solutions when the right combination of a short-ranged attraction and a long-ranged electrostatic repulsion exists. In this paper, we investigate the temperature effect on the dynamic cluster formation and try to pinpoint the transition concentration from a monomeric protein phase to a cluster phase. Interestingly, even at a relatively high concentration (10% mass fraction), despite the significant change in the SANS patterns that are associated with the change of the short-ranged attraction among proteins, the normalized short-time self-diffusion coefficient is not affected between 5 and 40 degrees C. This is interpreted as a lack of cluster formation in this condition. However, at larger concentrations such as 17.5% and 22.5% mass fraction, we show that the average hydrodynamic radius increases significantly and causes a large decrease of the normalized self-diffusion coefficient as a result of cluster formation when the temperature is changed from 25 to 5 degrees C.
