6Z5P

The RSL-R8 - sulfonato-calix[8]arene complex, P3 form, TRIS-HCl pH 8.5

Summary for 6Z5P

• Entry DOI: 10.2210/pdb6z5p/pdb
• Related: 6STH 6Z5G 6Z5M
• Descriptor: Fucose-binding lectin protein, sulfonato-calix[8]arene, beta-D-fructopyranose, ... (6 entities in total)
• Functional Keywords: calixarene, protein framework, cage, crystal engineering, molecular glue, synthetic receptor, macrocycle, biomaterial, supercharged, sugar binding protein
• Biological source: Ralstonia solanacearum
• Total number of polymer chains: 2
• Total formula weight: 23851.48

Authors

Ramberg, K.,Skorek, T.,Engilberge, S.,Crowley, P.B. (deposition date: 2020-05-27, release date: 2021-04-07, Last modification date: 2024-01-24)

Primary citation

Ramberg, K.O.,Engilberge, S.,Skorek, T.,Crowley, P.B.
Facile Fabrication of Protein-Macrocycle Frameworks.
J.Am.Chem.Soc., 143:1896-1907, 2021

PubMed Abstract: Precisely defined protein aggregates, as exemplified by crystals, have applications in functional materials. Consequently, engineered protein assembly is a rapidly growing field. Anionic calix[n]arenes are useful scaffolds that can mold to cationic proteins and induce oligomerization and assembly. Here, we describe protein-calixarene composites obtained via cocrystallization of commercially available sulfonato-calix[8]arene () with the symmetric and "neutral" protein RSL. Cocrystallization occurred across a wide range of conditions and protein charge states, from pH 2.2-9.5, resulting in three crystal forms. Cationization of the protein surface at pH ∼ 4 drives calixarene complexation and yielded two types of porous frameworks with pore diameters >3 nm. Both types of framework provide evidence of protein encapsulation by the calixarene. Calixarene-masked proteins act as nodes within the frameworks, displaying octahedral-type coordination in one case. The other framework formed millimeter-scale crystals within hours, without the need for precipitants or specialized equipment. NMR experiments revealed macrocyclemodulated side chain p values and suggested a mechanism for pH-triggered assembly. The same low pH framework was generated at high pH with a permanently cationic arginine-enriched RSL variant. Finally, in addition to protein framework fabrication, enables structure determination.

PubMed: 33470808
DOI: 10.1021/jacs.0c10697

Experimental method

X-RAY DIFFRACTION (1.42 Å)