Disulfide Cyclization Peptide Synthesis Case

Disulfide Cyclization Peptide Synthesis Case

 

Peptide Sequence	5-FAM-XXCXXCXXXXC (Cys6-Cys11 disulfide bridged)
Length	11 AA
Purity	95%
M.W	1522.67
Modification	N-Terminal 5-FAM, Disulfide Cyclization

 

HPLC results:

 

MS results:

 

Project Overview & Synthetic Strategy

Background & Challenge:

 A research client required the synthesis of a hydrophobic peptide sequence labeled with 5-FAM at the N-terminus, featuring a specific intra-molecular disulfide bridge. The major challenge in this project was preventing potential fluorophore degradation during the oxidation phase, while managing the regioselective formation between Cys6 and Cys11 without leading to undesirable parallel oligomers or incomplete cyclization, which commonly plagues standard air oxidation protocols.

Biorunstar’s Solution:

To guarantee a high-purity yield and flawless structural integrity, Biorunstar’s technical team implemented a precise, high-dilution solution-phase oxidation framework post-cleavage. By rigorously controlling the pH chemistry and optimizing buffer parameters, we accelerated the target disulfide-bond formation while completely eliminating linear impurities and dimeric byproducts.

Results:

As demonstrated by the downstream analytical HPLC data below, the target cyclic peptide was delivered with a superb purity profile of 95%, showcasing sharp peak symmetry and exceptional batch consistency.