How did Sanger determine the amino acid sequence of insulin?
It was a process of meticulous dissection and identification. We started by breaking the insulin molecule into smaller peptides using enzymes like trypsin. Then, we used techniques like chromatography and electrophoresis to separate these smaller pieces. The challenge was to determine the order of amino acids within these peptides. We used methods like 'fingerprinting' and partial acid hydrolysis, followed by analysing the resulting fragments. It wasn't a single stroke of genius, but rather a steady, step-by-step accumulation of data. We simply kept at it until the sequence began to emerge, confirming the overall structure.
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