Dresden 2017 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 35: Focus: Polymer Crystallization - from Model Systems to New Materials I

CPP 35.7: Vortrag

Mittwoch, 22. März 2017, 12:15–12:30, ZEU 222

Real-time observation of non-classical protein crystallization — •Benedikt Sohmen¹, Marcus Mikorski¹, Andrea Sauter¹, Felix Roosen-Runge², Ralf Schweins², Fajun Zhang¹, and Frank Schreiber¹ — ¹Institut für Angewandte Physik, Universität Tübingen, Tübingen, Germany — ²Institut Laue-Langevin, Grenoble, France

In order to approach a better understanding of non-classical crystallization a huge diversity of mechanisms has been discussed recently [1,2]. Here, we present a combined SAXS and SANS real-time study of the crystallization pathways of β-lactoglobulin in the presence of CdCl₂ with respect to protein concentrations c_p and salt concentrations c_s. Depending on the location in the c_p-c_s phase diagram, different crystallization pathways are observed. For c_s < c^*, the solutions are clear and crystallization follows a classical one-step pathway. For c^* > c_s > c^**, the system enters a condensed regime where an intermediate phase prior to crystallization is observed. By investigating the structure and the temporal evolution of the intermediate phase we clarify its role with respect to crystallization. Based on our studies, we suggest that β-lactoglobulin can follow different non-classical crystallization pathways. The intermediate phase can act as both, a material reservoir and a crystal precursor. [1] De Yoreo et al., Science, 349, 2015, 6760 [2] Sauter et al., J. Am. Chem. Soc., 137, 2015, 1485-1491