1984 Volume 32 Issue 5 Pages 2040-2043
Protein was treated with 2-carboxy-1-hydroxy-4-naphthylmethyldime-thylsulfonium chloride to modify the tryptcphan residues in the chain. The product thus obtained was treated with trypsin and the tryptophan modified fragment (s) was selectively isolated by adsorption onto a Chelating Sepharose 6B column (Al3+ form). This procedure may also be extended to molecular biology.