出版社：American Society for Biochemistry and Molecular Biology
摘要：HDLs have been proposed to have antiatherogenic properties becauseof their role in reverse cholesterol transport as lipid acceptors.To elucidate the phospholipid profile of these particles, weused electrospray ionization mass spectrometry to examine thephosphatidylcholine (PC) and sphingomyelin (SM) compositionof HDLs purified from plasma and nascently generated in vitrofrom fibroblasts. We also quantitatively compared the phospholipidspresent in these lipoproteins between normal and Niemann-Pickdisease type B (NPD-B) subjects characterized by sphingomyelinase(SMase) deficiency. We demonstrated that plasma HDLs from NPD-Bwere significantly enriched in SM by an average of 28%, particularlythe palmitoyl SM (with an increase of 95%), which accountedfor 25–44% of total SM molecular species. Similarly, weobserved an increase of 63% in total SM levels in nascent HDLsprepared from NPD-B fibroblasts. Although PC levels in nascentHDLs were comparable between control and NPD-B cells, therewas a 95% increase in total PC levels similar to that of SMin plasma HDLs extracted from NPD-B subjects.
These data provide insight into the structure of HDLs and identifypotential new roles for SMase in lipoprotein metabolism.Abbreviations: apoA-I, apolipoprotein A-I; CID, collision-induced decomposition; ESI-MS, electrospray ionization-mass spectrometry; HDL-C, high density lipoprotein-cholesterol; NPD-B, Niemann-Pick disease type B; PC, phosphatidylcholine; SM, sphingomyelin; SMase, sphingomyelinase; SMPD-1, sphingomyelin phosphodiesterase-1
Supplementary key words electrospray ionization-mass spectrometry • phospholipids • sphingomyelin phosphodiesterase-1 gene • sphingomyelinase • high density lipoprotein
25–44% of total SM molecular species. Similarly, we observed an increase of 
