6egy

From Proteopedia

Crystal structure of cytochrome c in complex with mono-PEGylated sulfonatocalix[4]arene

Structural highlights

6egy is a 2 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.7Å
Ligands:	, ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CYC1_YEAST Electron carrier protein. The oxidized form of the cytochrome c heme group can accept an electron from the heme group of the cytochrome c1 subunit of cytochrome reductase. Cytochrome c then transfers this electron to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain.

Publication Abstract from PubMed

Noncovalent or supramolecular PEGylation, in combination with the site of administration, has great potential to increase the half-life of therapeutic proteins. To date, a variety of noncovalent PEGylation strategies have been devised. However, questions remain concerning the nature of the protein-PEG interaction. Here, we report structural analyses of a model system that comprised the lysine-rich cytochrome c and two PEGylated variants of sulfonatocalix[4]arene. Complex formation was characterized in solution by NMR spectroscopy. It was found that mono- or di-PEGylated sulfonatocalix[4]arene bound the protein similar to the parent calixarene. X-ray crystal structures at <2.7 A resolution of the PEGylated derivatives in complex with cytochrome c revealed that the PEG chains were mostly disordered or encapsulated within the calixarene cavity. These results suggest that there was minimal interaction between the PEG and the protein surface, providing further evidence in favor of PEG maintaining a random coil conformation.

Noncovalent PEGylation via Sulfonatocalix[4]arene-A Crystallographic Proof.,Mummidivarapu VVS, Rennie ML, Doolan AM, Crowley PB Bioconjug Chem. 2018 Nov 20. doi: 10.1021/acs.bioconjchem.8b00769. PMID:30445810^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Mummidivarapu VVS, Rennie ML, Doolan AM, Crowley PB. Noncovalent PEGylation via Sulfonatocalix[4]arene-A Crystallographic Proof. Bioconjug Chem. 2018 Nov 20. doi: 10.1021/acs.bioconjchem.8b00769. PMID:30445810 doi:http://dx.doi.org/10.1021/acs.bioconjchem.8b00769