标题:Relationship of membrane phospholipid composition, lactosylceramide molecular species, and the specificity of CMP-N-acetylneuraminate:lactosylceramide alpha 2,3-sialyltransferase to the molecular species composition of GM3 ganglioside.
出版社:American Society for Biochemistry and Molecular Biology
摘要:The ceramide molecular species specificity of rat brain neuron CMP-N-acetylneuraminate:lactosylceramide alpha 2,3-sialyltransferase (LacCer alpha 2,3-ST) was determined using 19 molecular species of lactosylceramide incorporated into liposomes prepared with purified rat brain phospholipids. The neuron enzyme displayed a distinct molecular species specificity (which was different than the specificity of liver LacCer alpha 2,3-ST) based on both the long-chain base and the fatty acid composition of the lactosylceramide. Specifically, compared to the liver enzyme, relatively high activities were obtained with d18:1-16:0, d18:1-22:1, and d18:0-18:0 lactosylceramide molecular species. When the lipid composition of the neuron microsomal membranes was altered to resemble that of rat liver Golgi membrane lipids, the activities towards d18:1-16:0, d18:1-22:1, and d18:0-18:0 lactosylceramide molecular species were significantly (P