Structure error sinks NIH-MIT-SNU peptide paper

by Cat Ferguson

A mistake in structure identification has sunk a paper by researchers at the NIH, MIT, and Seoul National University in the Cell Press journal Chemistry and Biology.

Here’s the notice for “Peptide-Based Inhibitors of Plk1 Polo-box Domain Containing Mono-anionic Phosphothreonine Esters and Their Pivaloyloxymethyl Prodrugs”: This article has been retracted at the request of the authors.
 

Our paper reported small peptide inhibitors of the Plk1 polo-box domain (PBD) that were designed to contain monoanionic phospho-threonine esters. Subsequent analysis has revealed that the structures of peptides 2b–2n, 2c*, 2m*, and 3; their associated serine to alanine (S/A) variants; and the X-ray cocrystal structure of 2m bound to the Plk1 PBD (PDB accession code 4MLU) are not as presented in the paper. The pThr residues, which were reported as being monoanionic or neutral, are instead dianionic and monoanionic, respectively. Therefore, the interpretation of the data as reflecting the ability of peptides containing a monoanionic phosphothreonine residue to exhibit high PBD-binding affinity and enhanced cellular efficacy as well as the role of pivaloyloxymethyl (POM) prodrug protection in the observed biological effects are not valid in light of the incorrect structural assignments. As a result, the authors retract the paper.

We received a quote from Milka Kostic, editor of Chemistry & Biology, via an email from a PR representative:

In this case, the authors of the paper noticed an error in their original analysis that affected the conclusions they had presented.  They reached out to the editorial office to discuss the situation, and agreed with our determination that retraction was the most appropriate way to alert the community to the issue.

The paper has yet to be cited, according to Thomson Scientific’s Web of Knowledge. We’ve contacted the authors, and will update with any new information.