Isolation and chemical characterization of neutral glycosphingolipids of human neutrophils.

Abstract

Six neutral glycosphingolipids were isolated from purified preparations of human neutrophils. The chemical structure of each compound was characterized by degradation with exoglycosidases, methylation analysis, and electron impact/desorption mass spectrometry. The following structures were assigned on the basis of these detailed analyses: Glc beta 1 leads to 1Cer Gal beta 1 leads to 1Cer Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Gal alpha 1 leads to 4Gal beta 1 leads to 1Cer GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer. Neutral glycosphingolipids containing N-acetylgalactosamine were not detected in human neutrophils. The major neutral glycosphingolipids were lactosylceramide and lactoneotetraosylceramide. Although lactoneotriaosylceramide accounts for only 10% of the neutral glycosphingolipid fraction, neutrophils are the most readily available source of this compound. We may conclude that human neutrophils, in contrast to human erythrocytes and platelets, contain as their major neutral glycosphingolipids lactoneo-type structures and smaller amounts of gala-type structures. These findings are discussed in terms of blood group antigens and glycosphingolipid changes due to malignancy.