Protein crystal lattices are dynamic assemblies: the role of conformational entropy in the protein condensed phase

• Published in: IUCrJ Vol. 5; no. Pt 2; pp. 130 - 140
• Main Authors: Dimova, Margarita, Devedjiev, Yancho D
• Format: Journal Article
• Language: English
• Published: England International Union of Crystallography 01.03.2018
• Subjects: conformational entropy; crystal growth; Crystal lattices; Crystal structure; Crystallization; dynamic disorder; elastic molecular shape; Entropy; local entropic force; Mathematical models; Molecular conformation; oscillating crystal lattice; protein crystals; Protein structure; Proteins; Research Papers; static disorder; X-ray crystallography; X-ray crystallography; local entropic force; oscillating crystal lattice; conformational entropy; protein crystals; crystallization; crystal growth; dynamic disorder; static disorder; elastic molecular shape
• ISSN: 2052-2525; 2052-2525
• DOI: 10.1107/s2052252517017833

Until recently, the occurrence of conformational entropy in protein crystal contacts was considered to be a very unlikely event. A study based on the most accurately refined protein structures demonstrated that side-chain conformational entropy and static disorder might be common in protein crystal lattices. The present investigation uses structures refined using ensemble refinement to show that although paradoxical, conformational entropy is likely to be the major factor in the emergence and integrity of the protein condensed phase. This study reveals that the role of shape entropy and local entropic forces expands beyond the onset of crystallization. For the first time, the complete pattern of intermolecular interactions by protein atoms in crystal lattices is presented, which shows that van der Waals interactions dominate in crystal formation.