Sunday Contemplations

It's been a lively time on the chemical interwebs.

The entire chiral space dinosaur story is kind of getting tedious at this point. While the allegations of plagiarism certainly needs to be investigated, adjudicated, and resolved, I was most intrigued by the post here at the Curious Wavefunction. I find it convenient that he brings up the famed geologist Charles Lyell - there is a personally beloved example of what might be termed geological/geochemical contingency that I perpetually bring up at these moments.

Xanthine oxidase. You may or may not remember this enzyme from undergraduate biochemistry (well, for those of you took such a class). I mention it since it is a fairly well-known example of an enzyme which uses molybdenum as a cofactor. There are a number of molybdenum-utilizing enzymes that organisms use. However, it has been observed that certain organisms prefer to use tungsten. These are usually so-called "extremophiles" (deep-sea hydrothermal vents, in particular), where tungsten is more abundant than molybdenum, as well as needing to do chemistry at higher temperatures and under far more anoxic conditions. Perhaps it is not as dramatic as the sorts of substitutions that have been bandied about by some (hello, #arseniclife!), I will admit. But it bears consideration - how might multiple perturbations along these lines shape and remodel biochemistry?

(For anyone who wants more info on the above, I'd suggest first checking out the work of Michael Adams at the University of Georgia. If you are just curious about a point I bring up, let me know so I can reference you properly.)

The other interesting point that was brought up, IMO, was the idea of convergent evolution. This relates broadly to the idea that there are going to be certain physical "boundary conditions" one has to consider. My latest book of interest on this is Living at Micro Scale - the Unexpected Physics of Being Small by David Dusenbery. Here, the focus is on microorganisms and - to recall Edward Purcell - life at low Reynolds numbers.

I don't have anything interesting to note about DHFR since I neither deal with drug discovery nor with the biochemistry of DHFRs. Although I wonder - what if that paper hadn't shown up in J. Med. Chem.? What if it had ended up in a more general-audience biochemistry journal? Would there have been the same response? Would anyone have even noticed it on the chemistry blogosphere? I wonder.

Anyway, I'm going to contemplate lipid bilayers, detergents, and how they are clearly conspiring to make my life difficult.