Biochemical engineering of the side chain of sialic acids increases the biological stability of the highly sialylated cell adhesion molecule CEACAM1

The biological half-life time of many glycoproteins is regulated via termin al sialic acids. In this study we determined the half-lives of two differen t cell adhesion molecules, CEACAM1 and the al-integrin subunit, in PC12-cel ls before and after biochemical engineering the side chain of sialic acids by the use of N-propanoylmannosamine. Both are transmembrane glycoproteins. While the immunoglobulin superfamily member CEACAM1 mediates homophilic ce ll-cell adhesion the alpha1-integrin subunit is involved in cell-matrix int eractions. We found that the half-life of the highly sialylated CEACAM1 is increased from 26 to 40 h by replacement of the N-acetylneuraminic acid by the novel, engineered N-propanoylneuraminic acids, whereas the half-life of the alpha1-integrin subunit remains unaffected under the same conditions. This demonstrates that biochemical engineering not only modulates the struc ture of cell surface sialic acids, but that biochemical engineering also in fluences biological stability of defined glycoproteins. (C) 2001 Academic P ress.