Practical Protein Chemistry - A. Darbre 1989

Methods for Solid-Phase Amino Acid Sequence Analysis
Cleavage on a Solid-Phase Sequenator
Cleavage of Anilinothiazolinone

TFA is used for cyclization in the solid-phase method. The Cleavage reaction time and The amount of acid added are of critical importance: a short cleavage time results in incomplete cyclization, whereas a prolonged time causes non-Specific Cleavage of peptide bonds and an increase in contamination from cleaved thiazolinones. It is recommended to carry out the cyclization for 8 min at 45 °C. The optimal acid addition time can be determined using bradykinin, which contains Proline residues at positions 2, 3, and 7. The reaction time is considered sufficient if the fourth cleavage cycle contains no more than 10% residual proline. In addition, the yield of the third proline residue (the seventh N-terminal amino acid) should not drop sharply compared to the content of the preceding proline residues. Cleavage using TFA becomes more efficient if the Column is purged with nitrogen prior to acid addition [43].



Last update: 06/08/2026

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