Crosslinkers

BioActs provides a range of PEG based crosslinkers, which are water-soluble and unable to penetrate biological membranes. These crosslinkers are beneficial to transfer their hydrophilic spacer to the crosslinked biomolecule thereby reducing the potential of aggregation and precipitation of the complex. The crosslinker is one of well-known protein modification reagents that having a variety of applications in life science research and assay development. Crosslinkers are selected on the basis of their chemical reactivity and properties that affect their behavior in different applications.

One of the most common applications for crosslinkers is the production of protein conjugates. Conjugates are often prepared by attachment of an enzyme, fluorophore or other molecule to a protein that has affinity for one of the components in the biological system being studied. Another important application is immobilization of biomolecules such as protein or antibody onto solid supports for affinity purification or sample analysis. The supports may be nitrocellulose, polystyrene plates or beads, polymers, nanoparticles or glass slides. Crosslinkers are also used for in vivo crosslinking in order to identify neighbor protein relationships and ligand-receptor interactions.

Other important usage of crosslinkers is label transfer that involves a label transfer from a known protein to an unknown interacting protein. The label transfer agent comprises interacting molecules and a labeling agent connected through a crosslinker. The linkage might be cleaved when interacting with another molecule, and the label is transferred to new molecule. Furthermore, crosslinkers can be used to study the structure and composition of proteins in samples. Some proteins are difficult to study because they exist in different conformations with varying pH or salt conditions. One way to avoid conformational changes is to crosslink subunits. Also, various crosslinkers with varying lengths and functionalities can be utilized in cell membrane structural studies to determine the location and the environment within a cell’s lipid bilayer. Fluorescent tags are used to identify proteins, receptors or other molecules inside and outside the membrane.