Showing posts with label synthetic biology. Show all posts
Showing posts with label synthetic biology. Show all posts

Thursday, June 20, 2013

Science by press release

I woke up today with the news that researchers at the University of Aveiro had, "for the first time", altered the translational apparatus of an organism. I was outraged with the news: not with the science itself, but with the mindless hype surrounding it: actually, such a modification had already been performed in 2011 in C. elegans . I first thought that the "first time evah" pitch had been added by ignorant journalists, but the hype was already present in the press release from Univ. Aveiro!
The research publicized today is good and interesting, no doubt about that, but the quest for "good press" should never come at the expense of the truth. There is no excuse for that. Every bit of "good press" achieved with hype/exageration unfairly benefits those institutions and/or researchers with no moral qualms, leaving those researchers who are honest enough to not misrepresent their results in a disadvantage.

I've always disliked "science by press release", because (all other things being equal) it disproportionately benefits those who have access to the mass media, or who can afford publicists. Hyped press releases are even worse. And this can only end when science journalists stop relying on press releases to decide what is newsworthy. Though I strongly believe that such a day will not happen in the next 5 * 109 years.


Addendum: Previous reports all reassigned a STOP codon to an unnatural aminoacid. The report from Univ. Aveiro is indeed the first time that a non-STOP codon has been reassigned in an organism. This difference is unfortunately not present in the press release. I still stand by all other points on my post.

Thursday, August 30, 2012

Advances in peptide chemistry

Protein synthesis is nowadays achieved through molecular biology techniques: the relevant gene is cloned in an appropriate vector, over-expressed with e.g. a poly-histidine tag, and then purified through high affinity chromatography. Peptide chemistry is therefore often forgotten by biochemists, unless we need to order a short customized peptide from a commercial source.
Danishefsky et al. have now combined solid phase peptide synthesis, native chemical ligation and metal-free dethyilation to synthesize a number of analogues of human parathormone. Their strategy afforded native parathormone with higher purity than obtained from commercial sources, as well as pure analogues not achievable by any other means. These analogues were shown to be much more stable (10% decomposition in 7 days) than parathormone ,(>90% loss in 7 days), and to be as active as parathormone when injected to mice.
This is a very interesting work, which should pave the way towards the synthesis of long-lived synthetic peptide hormones, thus potentially decreasing the number of injections needed to control hormone levels in patients suffering from impaired endocrine function.

Tuesday, September 27, 2011

Coming soon to a worm near you....

Three possible stop codons are common in mRNA: UGA, UAA and UAG. These codons usually bind release factors, that prompt the release of of the nascent amino acid chain from the ribosome. Some organisms, however, contain tRNA complementary to one of these codons. In these organisms, that codon no longer triggers the ending of the translation process, but codes an amino acid instead. Several researchers have used this special tRNA to develop mutant cells with expanded genetic codes.Greiss and Chin have now taken this a step further: they have engineered a mutant strain of the worm C. elegans that translates every UAG codon as an artificial aminoacid. It was a complex endeavour (details are in their paper...) that surely would have deserved a well-publicized press conference :-)