Science 28 July 2006:
Vol. 313. no. 5786, p. 440
DOI: 10.1126/science.313.5786.440b
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Letters

Questions About Mass Spectrometry Data

I am writing to express my personal concerns about Hao Xin's article "University clears Chinese biophysicist of misconduct" (News of the Week, 28 Apr., p. 511).
On 19 April, Hao sent me an interview request regarding an alleged misconduct case against Xiao-Qing Qiu of Sichuan University. According to Hao, Qiu had told her that the mass spectrometric analysis (MS) I did for his project verified his hypothesis that there was a "thiolactone ring" present in the protein pheromonicin. Hao asked me to explain to her in lay terms what I did and what the significance of this ring was. Hao's email brought to my attention Qiu's paper, "An engineered multidomain bactericidal peptide as a model for targeted antibiotics against specific bacteria" (1). Reading the paper, I found that data from liquid chromatography-mass spectrometry (LC-MS) analysis were used to confirm the presence of the thiolactone ring in pheromonicin (p. 1481). I told Hao that I performed an MS analysis for Qiu at his request in 2003, but the results of the analysis I performed do not support the findings of the above-referenced article.

Qiu's stated interest with regard to the sample he provided to me in 2003 was, as above, in confirming the presence of the thiolactone ring in pheromonicin. On the basis of my memory and saved documents, his samples did not contain peptides at the predicted peptide masses within the mass measurement accuracy of the instrument or any masses matching the tryptic peptides of pheromonicin. I informed Qiu of this finding in early July of 2003. I do not know how Qiu obtained the MS data for his paper. However, I explained explicitly to Hao that the MS data presented in the paper have high mass measurement errors and should not have been used in the paper even if they were observed in mass spectra. The ultimate proof, of course, will be the reproducible production of the functional polypeptide based on Qiu's protocol.

Haiteng Deng
The Proteomics Resource Center
The Rockefeller University
1230 York Avenue
New York, NY 10021, USA
E-mail: dengh@rockefeller.edu

Reference

X.-Q. Qiu, Nat. Biotechnol. 21, 1480 (2003).