RGD Amino Acid Lettering Convention

[Xittenn]

How is it that Arginine is labeled R and Aspartate is labeled D? Is there a source on the list, the 'magic 20' at least with their respective letter and a reason why? I assume this is something similar to Pb Lead-Plumbum? I don't remember this from the biochemistry books I've read. They where all from the 70's, would that have mattered?

 

I will be receiving my fully up to date biochemistry reference title, but not for another three weeks!

[Kaeroll]

I'm not sure there's actually any reason for the choices. Some are evident, such as A for Alanine or C for Cysteine; others slightly less so, but still you can see why, such as F for Phenylalanine.

 

I'm guessing when they got to lettering Aspartate, Glutamate, Glutamine, and the others with seemingly random letters they just used those remaining.

[Xittenn]

I was afraid of that......................I'm not so good with random lettering! Note the title Ammino..............

[hermanntrude]

it's possible it's related to their names in another language

[Xittenn]

What about the names of the scientists who discovered them or something? Ah probably not! They could have numbered them......................

[Kaeroll]

I don't think either of those are the case, though hermanntrude's suggestion is more likely. I remember being told that a few are alphabetical, after a fashion; e.g. Asp is D; Glu, which is one carbon longer, is E. Honestly not sure though.