A blog by two chemists working in chemistry and chemical biology

Tuesday, 29 January 2013

George Orwell's rules on writing: applicable to science?

The 65th anniversary of George Orwell’s 1984 this year and the BBC is putting on many programs discussing the work of the great author.  Orwell had some very strong views on how things should be written and wrote an essay on the subject about 6 rules that he thought should be at the centre of any piece of writing, so can they be applied successfully to science writing?

Monday, 28 January 2013

Bio-orthogonal profiling of protein methylation

Protein methylation is an important biological process e.g. histone lysine methylation is involved in both gene activation (on histone 3 and Lys 4, 36 and 79) and silencing (H3 Lys 9 or 27 and H4 Lys 20). But how can other protein methyltransferases (PMTs) be investigated? Genetic approaches are always useful, but can have limitations particularly if your protein isn’t very common, forms complexes with other proteins (which would be disrupted by its absence and cause phenotypic changes beyond protein methylation) or if your process results in a non-viable cell. Chemical approaches would be extremely useful and complimentary, but as always problems with selectivity have to be overcome; a particular problem with PMTs as SAM (S-Adenosyl methionine) is a particularly prolific enzyme co-factor.

What to do then? Islam et. al. have developed a rather elegant solution that could allow general examination of a variety of PMTs, by creating mutants of proteins that can accept a synthetic azido-SAM donor. The enzyme then tags its target as before but instead of a methyl an azide containing group is left behind, this can subsequently be reacted with tags (like biotin) which contain strained alkynes in a bio-orthogonal manner. 

Wednesday, 23 January 2013

Viva Survivor: Baldwin's rules

This is the first of the basic science posts we will be running about once a week; first up is Baldwin's rules (or guidelines as many prefer), for more detail look here


Baldwin’s rules are empirical observations of possible cyclisation reactions, classified according to the size of the ring being formed, the nature of the electrophilic portion of the molecule and whether the bonds are broken inside or outside of the ring.  Although the based on empirical observation they use stereochemical reasoning including orbital overlap and the preferred angle of attack of a nucleophile. Because they are essentially empirical they are not really rules in the Woodwood—Hoffman sense of the word, but should be thought of as guidelines; there are exceptions!

Sunday, 20 January 2013

the stirrer bar

As you might be able to tell this is a new blog making it's way out into the big bad world wide web. Hopefully the title implies that this is going to be a science blog, and the fact that it's written by a couple of chemistry graduates probably gives you an idea of our area of interest. 

There are many chemistry blogs out there already and seeing as neither of us works on total synthesis (which is covered very well by other blogs here and here) or the pharmaceutical industry (covered excellently here) so we are going to try to write about our major area of interest namely chemistry at the interface of chemistry and biology. 

We are hoping that the blog can become a bit of a resource for people looking to learn a bit of new chemistry and so we are going to put up some named reaction posts and synthesis we like, but also posts on broader scientific areas we find interesting. Hopefully someone other than us two will find it interesting as well...