Amino-terminal sequence analysis of proteins purified on a nanomole scale by gel electrophoresis.

A simple, rapid, manual technique is described for determining the amino-terminal amino acid sequence of proteins on a nanomole scale. In this modification of the 5-dimethylaminonaphthalene-1-sulfonyl-Edman degradation, inorganic carriers permit convenient manipulation of small amounts of protein, and use of the detergent sodium dodecyl sulfate throughout the procedure maintains protein solubility. Nanomole quantities of pure protein for such sequence analysis are readily isolated from multicomponent systems by analytical scale polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Proteins are recovered quantitatively from the gel by elution. The method is therefore suitable for characterization of the proteins derived from multichain enzymes and viruses.