Efficient biochemical engineering of cellular sialic acids using an unphysiological sialic acid precursor in cells lacking UDP-N-acetylglucosamine 2-epimerase

Sialic acids comprise a family of terminal sugars essential for a variety o f biological recognition systems. N-Propanoylmannosamine, an unphysiologica l sialic acid precursor, is taken up and metabolized by mammalian cells res ulting in oligosaccharide-bound N-propanoylneuraminic acid. N-Propanoylmann osamine, applied to endogenously hyposialylated subclones of the myeloid le ukemia HL60 and of the B-cell lymphoma BJA-B, both deficient in UDP-N-macet ylglucosamine 2-epimerase, is efficiently metabolized to CMP-N-propanoylneu raminic acid resulting in up to 85%, of glycoconjugate-associated sialic ac ids being unphysiological N-propanoyleuraminic acid. Thus, UDP-N-acetylgluc osamine 2-epimerase-deficient cell lines provide an important experimental progress in engineering cells to display an almost homogeneous population o f defined, structurally altered sialic acids. (C) 2001 Published by Elsevie r Science BN. on behalf of the Federation of European Biochemical Societies .