Product Name: EDC.HCl

Category: Peptide Reagents

CAT: 40108

EDC.HCl; EDAC.HC

1-Ethyl-3-(3-dimethyllaminopropyl)carbodiimide hydrochloride

Serving as a water-soluble carbodiimide for rapid preparation of peptide conjugates, EDC or EDAC is a zero-length cross-linking agent used to couple carboxyl groups to primary amines. This cross-linker has been used in diverse applications such as forming amide bonds in peptide synthesis, attaching haptens to carrier proteins to form immunogens, labeling nucleic acids through 5’ phosphate groups and creating amine-reactive NHS-esters of biomolecules. EDC reacts with a carboxyl to form an amine-reactive O-acylisourea intermediate. If this intermediate does not encounter an amine, it will hydrolyze and regenerate the carboxyl group. In the presence of N-hydroxysulfosuccinimide (Sulfo-NHS), EDC can be used to convert carboxyl groups to amine-reactive Sulfo-NHS esters. This is accomplished by mixing the EDC with a carboxyl containing molecule and adding Sulfo-NHS.

As shown in this figure, EDC reacts with a carboxyl group on molecule #1, forming an amine-reactive O-acylisourea intermediate. This intermediate may react with an amine on molecule #2, yielding a conjugate of the two molecules joined by a stable amide bond. However, the intermediate is also susceptible to hydrolysis, making it unstable and short-lived in aqueous solution. The addition of Sulfo-NHS (5 mM) stabilizes the amine-reactive intermediate by converting it to an amine-reactive Sulfo-NHS ester, thus increasing the efficiency of EDC-mediated coupling reactions(1,2). The amine-reactive Sulfo-NHS ester intermediate has sufficient stability to permit two-step cross-linking procedures, which allows the carboxyl groups on one protein to remain unaltered.

Highlights:

• Efficiency of EDC-mediated coupling is increased in the presence of Sulfo-NHS
  By combining EDC and Sulfo-NHS, amine reactive Sulfo-NHS esters can be created on any carboxyl-containing molecule
• Amide bonds formed with this cross-linking reaction provide a neutral linkage
  Excess reagent and cross-linking byproducts are easily removed by washing with water or dilute acid
• EDC is water soluble, so cross-linking can be done in physiologic solutions without adding organic solvent
• High purity, crystalline EDC can be used to create high-purity activated derivatives
  

Applications for EDC

• Conjugate carboxyl to amine groups in peptides and proteins
• Convert carboxyls to amine-reactive Sulfo-NHS esters
• Cross-link proteins to carboxyl coated beads or surfaces
• Activate nanoparticles with amine-reactive Sulfo-NHS esters
• Couple haptens to carrier proteins (e.g. attach a peptide to KLH)
• DNA labeling through 5’ phosphate groups
  

References:

1. Grabarek, Z. and Gergely, J. (1990) Zero-length crosslinking procedure with the use of active esters. Anal. Biochem. 185, 131-135.
2. Staros, J.V., Wright, R.W. and Swingle, D.M. (1986) Enhancement by N-hydroxysulfosuccinimide of water-soluble carbodiimide-mediated coupling reactions. Anal. Biochem. 156, 220-222
3. DeSilva, N.S. (2003) Interactions of Surfactant Protein D with Fatty Acids. Am. J. Respir. Cell Mol. Biol. 29, 757-770
4. Taniuchi, M., et al. (1986). Induction of nerve growth factor receptor in Schwann cells after axotomy. Proc. Natl. Acad. Sci. USA83, 4094-4098