News
February 14, 2008
Galα1-3Gal Neoglycoproteins as Heterophilic Blocking Agents
Heterophilic antibodies, which are endogenous antibodies found in human serum/plasma, may bind to the animal antibodies used in immunoassays and produce erroneous results. An example is the immunoglobulins that bind the Galα1-3Gal epitope and constitute ca. 1% of total serum IgG. These antibodies are responsible for the hyperacute rejection of xenografts and are thought to be synthesized in response to the Galα1-3Gal epitope produced by the human gut flora (Galili, 2005).
In a recent study it was shown that these antibodies interfered in an assay to measure galactose deficient anti-Gal IgG in the sera of patients with liver fibrosis and cirrhosis caused by infection by hepatitis C virus. This interference could be overcome by the inclusion of human serum albumin (HSA) attached to alpha-Gal obtained from Dextra Laboratories in the ELISA assay (Mehta et al. 2008).
We offer 3 alpha-Gal HSA neoglycoproteins that can be used in this application:
- NGP2330 Galα1-3Galβ1-4Glc-HSA 3-atom spacer
- NGP2334 Galα1-3Galβ1-4GlcNAc-HSA 3-atom spacer
- NGP3334 Galα1-3Galβ1-4GlcNAc-HSA 14-atom spacer
References
Gallili, U. (2005). The alpha-Gal epitope and the anti-Gal
antibody in xenotransplantation and in cancer immunotherapy. Immunol.
Cell Biol. 83:674-686
Mehta, S.A., Long, R.E.,
Comunale, M.A., Wang, M., Rodemich, L., Krakover, J., Philip, R.,
Marrero, J.A., Dwek, R.A. and Block, T.M. (2008). Increased Levels
of Galactose-Deficient Anti-Gal Immunoglobulin G in the Sera of
Hepatitis C Virus-Infected Individuals with Fibrosis and Cirrhosis. J.
Virol. 82(3):1259-1270
January 30, 2008
Blood Group A and B Neoglycoproteins
We have introduced new linker arm chemistry for our blood group A and B neoglycoproteins. This has been necessary because there were problems of poor manufacturing yields using these trisaccharides with our standard 3 and 14 atom linker arms and reports of lower substrate affinities, for example antibody binding, with the 20 atom linker. As a solution, we have developed a new proprietary polar 6 atom linker that we think will overcome our problems and will meet users’ needs. The new products will carry the catalogue numbers:
- NGP 6305 Blood Group A-BSA (6-atom spacer)
- NGP 6323 Blood Group B-BSA (6-atom spacer)
October 30, 2007
Over 80 new oligosaccharide products have been added to our online catalogue which has been re-arranged and updated.
July 30, 2007
Construction of our new cGMP facility is completed with the fitting out of two new laboratories using state-of-the-art equipment. Our thanks go to our contractors Clearfume for delivering on time and on budget.
May 16, 2007
Dextra has signed a carbohydrate service deal with a US company which includes $450,000 development payment and a 5% royalty fee. Press release.
April 20, 2007
New publication: 'Structural modification of a base disaccharide alters anti-adhesion properties towards Yersinia pestis' - Richard J Thomas, Andrew Hacking & Timothy JG Brooks. FEMS immunology & medical microbiology; Vol 49, No. 3, 410-14, April 2007
March 22, 2007
Dextra Laboratories has been acquired by Summit plc. This gives us the opportunity and investment to develop our expertise into GMP manufacture and become the world's leading specialist in carbohydrate synthesis, analysis and manufacture.
