Martín-Sosa Samuel, Martín María-Jesús, Castro María-Dolores, Cabezas José A, Hueso Pablo
Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, 37007 Salamanca, Spain.
Lipids. 2004 Feb;39(2):111-6. doi: 10.1007/s11745-004-1208-4.
The objectives of this work were to study the FA composition of milk gangliosides, as well as to gain further insight into the characterization of human milk gangliosides. The potential capacity of human milk gangliosides to adhere to human enterotoxigenic Escherichia coli (ETEC-strains) was also studied. Human milk gangliosides were isolated and identified by high-performance TLC or immunoassay. The latter also was used to assay bacterial adhesion. The FA composition of gangliosides was studied by GC. The presence of O-acetyl GD3 (Neu5,9Ac2alpha2-8 NeuAcalpha2-3Galbeta1-4GlcCer) and trace amounts of GM1 [Galgamma1]3-3GalNAcgamma1,-3(Neualpha2-3)Galbeta1-4GlcCerl in human milk was confirmed. Medium-chain FA were almost absent in colostrum, whereas in the subsequent stages they rose to 20%. The levels of long-chain FA decreased after colostrum. With respect to the degree of saturation, gangliosides from colostrum were richer in monounsaturated FA than gangliosides synthesized during the rest of the lactation period, opposite to the pattern for PUFA. A human-ETEC colonization factor antigen II-expressing strain showed binding capacity to human milk GM3 (NeuAcalpha2-3Gal[1-4GlcCer). New data on human milk gangliosides have been gathered. A thorough knowledge of their composition is needed since they may have important biological implications in regard to newborns' defense against infection.
这项工作的目标是研究乳神经节苷脂的脂肪酸（FA）组成，以及进一步深入了解人乳神经节苷脂的特性。还研究了人乳神经节苷脂与人肠产毒素大肠杆菌（ETEC菌株）黏附的潜在能力。通过高效薄层层析法或免疫测定法分离并鉴定人乳神经节苷脂。后者也用于检测细菌黏附。通过气相色谱法研究神经节苷脂的FA组成。证实了人乳中存在O-乙酰基GD3（Neu5,9Ac2α2-8NeuAcα2-3Galβ1-4GlcCer）和痕量的GM1 [Galγ1] 3-3GalNAcγ1，-3（Neuα2-3）Galβ1-4GlcCer。初乳中几乎不存在中链脂肪酸，而在随后阶段其含量上升至20%。初乳后长链脂肪酸水平下降。关于饱和度，初乳中的神经节苷脂比哺乳期其余时间合成的神经节苷脂富含更多单不饱和脂肪酸，这与多不饱和脂肪酸的模式相反。一株表达人ETEC定植因子抗原II的菌株显示出与人乳GM3（NeuAcα2-3Gal [1-4GlcCer）的结合能力。已收集到人乳神经节苷脂的新数据。由于它们可能对新生儿抗感染具有重要生物学意义，因此需要全面了解其组成。
