Edman degradation automated

Modem methods of peptide sequencing follow a strategy similar to that used to sequence insulin but are automated and can be carried out on a small scale A key feature is repetitive N terminal identification using the Edman degradation... 

The general idea of peptide sequencing by Edman degradation is to cleave one amino acid at a time from an end of the peptide chain. That terminal amino acid is then separated and identified, and the cleavage reactions are repeated on the chain-shortened peptide until the entire peptide sequence is known. Automated protein sequencers are available that allow as many as 50 repetitive sequencing cycles to be carried out before a buildup of unwanted by products interferes with the results. So efficient are these instruments that sequence information can be obtained from as little as 1 to 5 picomoles of sample—less than 0.1 /xg. 

N-terminal sequencing is normally undertaken by Edman degradation (Figure 7.5). Although this technique was developed in the 1950s, advances in analytical methodologies now facilitate fast and automated determination of up to the first 100 amino acids from the N-terminus of most proteins, and usually requires a sample size of less than 1 umol to do so (Figure 7.6). 

Fietzek, P. P., and Kiihn, K. Automation of the Sequence Analysis by Edman Degradation of Proteins and Peptides. 29, 1-28 (1972). 

Fig. 10. Automated Edman degradation of al-CB6-C2 of calf skin collagen. Relative yield of liberated PTH-glycine as a function of degradation cycles. Amount of the first glycine is arbitrarily set at 100 per cent...

Automation of the Sequence Analysis by Edman Degradation of Proteins and Peptides... 

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