Solid-phase Synthesis of Difficult Peptides and Peptide Conjugates


Project ID:  D2012-01



There is a need in the field of peptide synthesis and peptide conjugate synthesis for chemistry capable of linking sterically demanding amino acids to form difficult peptides. These difficult peptide sequences result when incomplete peptide bond formation and/or deprotection reactions occur at various stages in solid-phase peptide synthesis (SPPS). These problems occur with most of the common peptide coupling reagents and are more pronounced in SPPS due to the steric requirements of the resin. There is a need for linking chemistry that can facilitate the site-specific conjugation of an untold number of compounds to peptides and proteins, specifically PEGylating reagents, polymers, and saccharides.


Invention Description:

New method of synthesizing sulfonamide-modified peptides and peptide conjugates that solves current problems and allows installation of a sulfonamide directly to a growing peptide without the need to synthesize the sulfonamide-modified amino acids or peptides.



·       Allows for the sulfonamide to be attached to any position of an amino acid side chain during (SPPS).

·       Sulfonamide remains intact through the cleavage step of the peptide from the resin in order to affect the desired amide bond formation reaction as is required in the case of mixed methods for peptide or peptide conjugate synthesis.

·       Provides alternative method for achieving site-specific peptide PEGylation/modification to avoid the loss of biological activity.



·       Applications in which very high purity (>95 area-% by HPLC) peptides and peptide conjugates are required.


IP Status: U.S. Utility Patent #8,895,696 B1

Patent Information:
For Information, Contact:
Lokesh Mohan
Licensing Associate
The University of Toledo
Steven Sucheck
Rommel Talan
Partha Karmakar