Intra- and Intermolecular S-S bonds

Intramolecular S-S bonds

1-2 disulfide S-S bridges : We utilize orthogonal protection strategies to control specific bond formations for peptides containing 1-2 bridges.

1-2 disulfide S-S bridges + 1 free unprotected cysteine residue (N-term, C-term, or internal) : For peptides containing 1-2 bridges, we can also include a free unprotected cysteine residue on the sequence useful in conjugation.

≥ 3 disulfide S-S bridges : We can utilize either orthogonal protection strategies to control specific bond formations or form them naturally by creating the most thermodynamically stable product.

≥ 4 disulfide S-S bridges : Formed naturally by creating the most thermodynamically stable product.

Disulfide bridge(s) formed between cysteine residues of two (or more) peptide chains

MALDI matrix cluster ions as internal references for ion mobility measurements.
Mwangi JN, Todd DA, Chiu NH.
Springer Berlin Heidelberg; 2019.

From AnaSpec (Eurogentec's US subsidiary) : The 95% pure peptide (YSTCDFIM), was cyclized between the sulfur group of cysteine residue and the C-terminal and has a monoisotopic mass of 960.3721 Da.

Other constrained peptides