Protein Crosslink Service

What is Protein Crosslinking?

Proteins are essential macromolecules that perform various functions in the human body, such as catalyzing biochemical reactions, transporting molecules, and providing structural support. In order to understand how proteins work, it is necessary to study their structure and interactions. Protein cross-linking is a technique that enables researchers to chemically link amino acids within or between proteins. This technique can be used to identify protein interactions, determine protein structure and study protein function. The process can occur naturally in living cells or can be induced artificially in vitro. Cross-linking can occur between two proteins, or between a protein and a small molecule such as a ligand or drug. The resulting protein complexes can be analyzed using a variety of techniques, including mass spectrometry, gel electrophoresis, and protein blotting.

Protein cross-linking coupled with mass spectrometryProtein cross-linking coupled with mass spectrometry (Holding et al., 2015)

Creative Proteomics offers a range of protein cross-linking services, including in vivo and in vitro cross-linking, to help researchers gain insight into protein-protein interactions, protein structure and function. We work with researchers to develop customized crosslinking strategies to meet your specific needs.

Crosslinkers for Protein Crosslinking in Creative Proteomics

Crosslinker Type Reaction Chemistry Examples
Homobifunctional Amine-to-Amine DSS, BS3, EGS
Thiol-to-Thiol DTSSP, BM(PEG)2
Carbonyl-to-Carbonyl Glutaraldehyde
Aldehyde-to-Amine DFDNB
Azide-to-Alkyne CuAAC
Heterobifunctional Amine-to-Thiol SATA, GMBS
Amine-to-Carbonyl CDAP, DMTMM
Thiol-to-Carbonyl SPDP, Sulfo-SBED
Amine-to-Hydrazide HYNIC
Thiol-to-Azide Sulfo-SIAB
Cleavable Disulfide DSP, DTSSP-SS
Azobenzene SDA
Dithiocarbamate DTBP
Photoactivatable Arylazide Sulfo-SANPAH
Benzophenone Sulfo-SBED
Diazo Diazirine

In Vivo Crosslinking

In vivo crosslinking services enable the crosslinking of proteins within a living cell or organism, providing insight into the interactions of proteins in their natural environment. The approach involves treating cells or tissues with cross-linking agents that penetrate the cell membrane and cross-link proteins within the cell. We use a variety of cross-linking agents, including DSS, BS3 and EGS, to achieve amine-to-amine and thiol-to-thiol cross-linking reactions.

In Vitro Crosslinking

The in vitro crosslinking service enables crosslinking of purified proteins or protein complexes to provide insight into extracellular protein interactions. The approach involves treating the protein or protein complex with a cross-linking agent that can cross-link specific amino acid residues. We use a variety of cross-linking agents, including CDAP, SPDP and Sulfo-SIAB, to achieve cross-linking reactions of amine-carbonyl, thiol-carbonyl and thiol-azide.

Applications of Our Protein Crosslinking Services

  • Identify protein-protein interactions in complex mixtures, providing insight into signaling pathways, protein complexes, and drug targets
  • Study protein-DNA interactions to provide insight into transcriptional regulation and chromatin structure
  • Identify protein-ligand interactions and characterize small molecule inhibitors or protein function activators
  • Mapping the interfaces of protein complexes to provide insight into the structural basis of protein interactions
  • Mapping antibody epitopes to provide valuable information for the development of therapeutic antibodies


  1. Holding, Andrew N. "XL-MS: Protein cross-linking coupled with mass spectrometry." Methods 89 (2015): 54-63.
* This service is for RESEARCH USE ONLY, not intended for any clinical use.