Symansis' Soluble Receptors
Fc chimeric proteins as potent biological tools for research
Symansis' receptor proteins are mainly produced as extracellular domain (ECD) regions fused to the Fc region of human IgG1, with the aim of enhancing their activity. ECD-Fc fusion proteins often have an advantage of over soluble receptors because many receptors are only functional in dimeric form. Fusion to the Fc domain of IgG1 induces dimerisation due to the ability of the Fc domain to form disulfide bonds. The resulting dimeric receptor ECD-Fc should mimic the activated form of the receptor and possess enhanced affinity for its cognate ligand relative to its monomeric form. Fusion to the Fc domain could also confer increased half-life in vivo.
The complexity of biological systems is reflected in the myriad ways a protein can be regulated. While receptors for cytokines are well known for their role in the activation of signalling cascades within the cell, they also play a role outside of the cell. Many membrane bound receptor are also found in soluble form, due to cleavage from the cell surface. Soluble receptors may function as agonists or antagonists and may exist as monomers or oligomers. Examples of soluble receptors include receptors for growth hormone, interleukins, leptin and G-CSF
Chimeric proteins show promising results in clinical trials. The success of receptor ECD-Fcs as therapeutic agents emphasises the viability of using these chimeric molecules as powerful tools for research.
Symansis' range of receptor ECD-Fcs is produced by fusing human receptor ECD to human IgG1 and purified from human cells. These chimeric proteins contain human-specific glycosylation and are ideally suited for studies involving human proteins and cells. Symansis' receptor ECD-Fc fusion proteins can be used to neutralise the bioactivity of its cognate ligand in vitro and in vivo. They can also be used in studies to quantify receptor-ligand affinity by surface plasmon resonance (Biacore).
Symansis also has an increasing range of non-receptor ECD-Fc such as CD209L/DC-SIGNR and L-selectin Fc. These are cell surface glycoproteins involved in viral entry into cells (CD209L/DC-SIGNR) and cell adhesion of lymphocytes to endothelial cells (L-selectin). These chimeric glycoprotein ECD-Fcs can be used in studies elucidating their respective biological functions.