送交者: Godfather 于 2006-1-21, 15:29:28:
回答: 对丘小庆教授论文作假的质疑没有严格的学术根据 由 桂铭 于 2006-1-21, 03:16:53:
Unfortunately, my Chinese typing is terribly slow. Otherwise, I would write an article in Chinese to debate with you.
Qiu's idea may seem novel and scientifically sound. However, it was not a realistic approach. I strongly believe that, although he might be able to produce the fusion protein, he was unable to obtain the same protein as he described in the paper. Period! If somebody is interested in finding out the truth, please go back to the histroy of Colicins and Pheromones and to study their mechanisms first. Another way to look at it is to trace Qiu's work at AECOM and his postdoc lab where they initially worked on Colicin E1 (522 amino acid residues), and changed to Ia (626 amino acid residues) later. It is truly amazing that 2 different proteins in size, compoosition and physical properties can be purified by the exactly same procedure! Qiu was working on Ia only and published 2 papers on mutagenesis of Ia. As for the antibacterial peptides pheromones, they can increase the membrane permeability to function their activity. However, in order to maintain the activity, they have to maintain their original structure and confirmation. Once they are fused with other peptides or proteins, I have all the reasons to doubt their original activity.
Now, I still back my initial assessment in which I believe that antibacterial activity was from Streptomycin. If he ran a gel filtration column for the purification, I would make a different conclusion. Actually, during the CM-sepharose column, Streptomycin was concentrated from his sample rather than removed under his conditions.
Regarding the definition of activity, MIC is the common indicator for antibiotics. In order to obtain an accurate MIC value, one has to do a series of dilutions. The reason is quite simple. In most cases, activity is concentraton dependent. Somebody would argue that Streptomycin is not a broad spectrum antibiotic. That's true only at low concentration. When the tested concentrations are above certain values, for instance, 30 mg/L, Streptomycin can also kill staphylococci and Enterococci. That's why Qiu's samples showed activity against these gram-positive bacteria. "Narrowed" and "broad" are relative terms.
Certainly, I only represent my own opinion that was based on published results and claims. In addition, I am not interested in any business conflicts. Just let science speak for itself!