Why are peptides containing Cys, Met, or Trp difficult to synthesize?

Pepsides containing cysteine (Cys), methionine (Met), or tryPepsides containing cysteine (Cys), methionine (Met), or tryptophan (Trp) can be difficult to synthesize because they are not basic amino acids and require the addition of a free amino group to form their peptide bonds.

Cys, for example, is a nonpolar amino acid that does not contribute to the formation of a hydrogen bond with another amino acid. Therefore, it requires the addition of a free amino group to form its peptide bond. This can be challenging in synthetic settings, as it requires the use of a free amino acids or an amino acid derivative that can provide a free amino group.

Similarly, Met and Trp also require the addition of a free amino group to form their peptide bonds. Met is a polar amino acid that can contribute to the formation of a hydrogen bond with another amino acid, but it still requires the addition of a free amino group. Trp is a polar amino acid that cannot contribute to the formation of a hydrogen bond and therefore requires the addition of a free amino group to form its peptide bond.

In summary, peptones containing cysteine, methionine, or tryptophan can be difficult to synthesize because they require the addition of a free amino group to form their peptide bonds, which can be challenging in synthetic settings.

Website: https://www.ks-vpeptide.com/