Crystal structure of a mirror-image L-RNA aptamer (Spiegelmer) in complex with the natural L-protein target CCL2.
Oberthur, D., Achenbach, J., Gabdulkhakov, A., Buchner, K., Maasch, C., Falke, S., Rehders, D., Klussmann, S., Betzel, C.(2015) Nat Commun 6: 6923-6923
- PubMed: 25901662 
- DOI: https://doi.org/10.1038/ncomms7923
- Primary Citation of Related Structures:  
4R8I - PubMed Abstract: 
We report the crystal structure of a 40 mer mirror-image RNA oligonucleotide completely built from nucleotides of the non-natural L-chirality in complex with the pro-inflammatory chemokine L-CLL2 (monocyte chemoattractant protein-1), a natural protein composed of regular L-amino acids. The L-oligonucleotide is an L-aptamer (a Spiegelmer) identified to bind L-CCL2 with high affinity, thereby neutralizing the chemokine's activity. CCL2 plays a key role in attracting and positioning monocytes; its overexpression in several inflammatory diseases makes CCL2 an interesting pharmacological target. The PEGylated form of the L-aptamer, NOX-E36 (emapticap pegol), already showed promising efficacy in clinical Phase II studies conducted in diabetic nephropathy patients. The structure of the L-oligonucleotide[Symbol: see text]L-protein complex was solved and refined to 2.05 Å. It unveils the L-aptamer's intramolecular contacts and permits a detailed analysis of its structure-function relationship. Furthermore, the analysis of the intermolecular drug-target interactions reveals insight into the selectivity of the L-aptamer for certain related chemokines.
Organizational Affiliation: 
Laboratory for Structural Biology of Infection and Inflammation, University of Hamburg, c/o DESY Building 22a, Notkestrasse 85, 22607 Hamburg, Germany.