Measurement of Tryptophan in Peptides by Acid Hydrolysis in the Presence of Phenol and its Application to the Amino Acid Sequence of a Sea Anemone Toxin

Abstract

The addition of phenol (about 1%) to 6 m HC1 largely prevented destruction of tryptophan during hydrolysis of peptides at 110°C for 22 hr. Tryptophan recovery depended on the volume of 6 m HC1 containing phenol and the concentration of phenol. The maximum tryptophan recovery was 85% for a standard amino acid mixture. The recovery was slightly lower for proteins. This hydrolytic procedure was advantageous for micro amino acid analysis using a conventional highperformance liquid chromatography with a precolumn labeling technique. The method was used in the amino acid sequence analysis of a minor component of sea anemone toxins isolated from Anthopleura fuscoviridis. The toxin consisted of 48 amino acid residues with three tryptophan residues. © 1987, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.