Selective amino acid labelling

[Chen Ho An]

I need a reference for the selective labelling of a particular amino acid.
The method I'm interested in is the use of amber stop codon (I think)
mutation that allow selective incorporation of unusual amino acid (e.g
tryptophan with a fluorescent label attached) into protein.  I have read a
paper that describe something similar but can't seem to find it again.
Your help will be greatly appreciated.



-chen