(that's actually supposed to be one long word - the spacers were added to prevent ultra-scrolling. 1913 characters!). And to think I was about to just put in "antidisestablishmentarianism"...
And if you must know, it's a chemical - "tryptophan synthetase A protein, an enzyme with 267 amino acids" (from the linked page).
Edit: add the definition of the chemical as well as explain the link
Edit: Forgot to add change log.