Chemistry LibreTexts - Protein Sequencing
The basics of Edman degradation.
Genosphere Biotechnologies - Edman DegradationContains a very clarifying figure depicting the Edman degradation chemistry. It's not so complicated!
Biology LibreTexts - Protein Sequencing, Peptide Mapping, Synthetic GenesThis is a great article. It's a little lengthy, but it pulls together a lot of biochemistry and molecular biology. Reading this is a good warm-up for MCAT passages.