摘要:
Frontal affinity chromatography with mass spectrometric detection (FAC/MS) was developed as an effective method for rapid determination of K-d values for alpha-Gal derivatives binding to human anti-Gal IgG antibodies. Using this method, K-d values for 23 alpha-Gal compounds were determined for the first time, including an alpha-Gal terminated N-linked oligosaccharide which mimics a single N-glycoform present on the surface of animal cells. A mixture of eight alpha-Gal derivatives, a model for an alpha-Gal compound library, was successfully screened against this anti-Gal IgG using FAC/MS. The analyte breakthrough sequence, indicated by the ion chromatogram, reflected the magnitude of the K-d values, confirming its potential application in the screening of new alpha-Gal derivatives and mimetics. Ten alpha-Gal derivatives were designed and synthesized chemically or enzymatically. Among the compounds analyzed, trivalent compound 26 demonstrated the strongest binding affinity to anti-Gal IgG with a K-d value of 3.1 muM. The alpha-Gal terminated N-linked oligosaccharide 28 had a K-d value of 8.6 muM.