To my knowledge there are 23 proteinogenic amino acids.

From which 21 are used in eukaryotic organisms.

From which 20 are coded by DNA.

That's fine.

 

But how many non-proteinogenic amino acids do we know, both natural and synthetic?

I have googled inconvenient range of numbers (from 250 to 1500).

 

Write down, if you will, also a source of your answer.

Thank you.

Your problem is that your question is too broad. The number of synthetic amino acids would be huge and the number of possible ones much larger still. Why exactly do you need to know?

Out of curiosity.

Well the general structure of an aminoacid is H₂N-CHR-COOH where R can be whatever you like and it would still be classed as an amino acid. So to answer your question in that regard: infinite.

Yes. Hypothetically. I was just wondering if there is a reliable number of amino acids we discovered.

This

http://www.cas.org/content/counter

gives you an idea of how many chemicals have been reported in the scientific literature. (66 million or so)

It's fair to assume that not all known compounds are documented (lots of pharmaceutical companies keep their data under wraps)

In principle, you could search through them all looking for amino acids.

I doubt that anyone has bothered.

 

Another lower bound to the number of amino acids is to consider that essentially any protein will have free amino, an acid, groups (if only at the ends).

So the purpose of every single gene that codes for a protein, is to make an amino acid.

 

That's a lot of different ones.

Edited January 28, 201511 yr by John Cuthber

WOW. Thank you!! That's a lot of different ones indeed.