4R0O

Crystal structure of PEGylated plastocyanin at 4.2 A resolution

Summary for 4R0O

• Entry DOI: 10.2210/pdb4r0o/pdb
• Descriptor: Plastocyanin, COPPER (II) ION, 1-methylpyrrolidine-2,5-dione (3 entities in total)
• Functional Keywords: pegylation, electron transport
• Biological source: Phormidium laminosum
• Total number of polymer chains: 4
• Total formula weight: 46910.85

Authors

Cattani, G.,Vogeley, L.,Crowley, P.B. (deposition date: 2014-08-01, release date: 2015-10-07, Last modification date: 2024-11-06)

Primary citation

Cattani, G.,Vogeley, L.,Crowley, P.B.
Structure of a PEGylated protein reveals a highly porous double-helical assembly.
NAT.CHEM., 7:823-828, 2015

PubMed Abstract: PEGylated proteins are a mainstay of the biopharmaceutical industry. Although the use of poly(ethylene glycol) (PEG) to increase particle size, stability and solubility is well-established, questions remain as to the structure of PEG-protein conjugates. Here we report the structural characterization of a model β-sheet protein (plastocyanin, 11.5 kDa) modified with a single PEG 5,000. An NMR spectroscopy study of the PEGylated conjugate indicated that the protein and PEG behaved as independent domains. A crystal structure revealed an extraordinary double-helical assembly of the conjugate, with the helices arranged orthogonally to yield a highly porous architecture. Electron density was not observed for the PEG chain, which indicates that it was disordered. The volume available per PEG chain in the crystal was within 10% of the calculated random coil volume. Together, these data support a minimal interaction between the protein and the synthetic polymer. Our work provides new possibilities for understanding this important class of protein-polymer hybrids and suggests a novel approach to engineering protein assemblies.

PubMed: 26391082
DOI: 10.1038/nchem.2342

Experimental method

X-RAY DIFFRACTION (4.2 Å)