Your crystallographic Thanksgiving – Tryptophan!

Our contributor from the good ol' US of A, Sara Callori, celebrates Thanksgiving on Crystallography 365!

What does it look like?

Crystal structure made with VESTA.
Red: Oxygen, Blue: Nitrogen, Brown: Carbon, White: Hydrogen.

What is it?

As an American living in Australia, this is the time of year when I get a bit homesick for a real autumn, and this week I'm especially missing Thanksgiving. I could make up for it by hosting one myself, but since it's basically summer Down Under, it's way too hot to do all that cooking. However, I can celebrate in a crystallographic way – by posting the structure of tryptophan!

Tryptophan is an essential amino acid that helps cells form new proteins. It's found in most-protein based foods. The pseudo-scientific urban legend surrounding tryptophan is that it's the tryptophan in turkey that makes you sleepy after a big Thanksgiving dinner. However, this isn't actually the case, as turkey has the same amount of tryptophan in it as chicken or pork and many other types of foods, so it isn't what causes that post-pumpkin pie slump. (Personally I blame it on a very large meal accompanied by several glasses of wine.)

Where's this structure from?

Apparently tryptophan is difficult to successfully crystalize, so successful reports on its structure have only surfaced in the last decade. The structure above is L-typtophan that was recently published by C. H. Görbitz, K. W. Törnroos and G. M. Day in Acta Crysltallographica B. (http://scripts.iucr.org/cgi-bin/paper?S0108768112033484)

Tags: food   amino acid   Thanksgiving