The first paragraph (144 words).Glycosphingolipids (GSLs) synthesized in Golgi apparatus by sequential transfer of sugar residues to a ceramide lipid anchor are ubiquitously distributing on vertebrate plasma membranes. Standardized method allowing for high throughput structural profiling and functional characterization of living cell surface GSLs is of growing importance because they function as crucial signal transduction molecules in various processes of dynamic cellular recognitions. However, methods are not available for amplification of GSLs, while the genomic scale PCR amplification permits large-scale mammalian genomics and proteomics. Here we communicate such an approach to a novel "omics", namely glycosphingolipidomics based on the glycoblotting method.The method, which involves selective ozonolysis of the C-C double bond in ceramide moiety and subsequent enrichment of generated GSL-aldehydes by chemical ligation using aminooxy-functionalized gold nanoparticle (aoGNP) should be of widespread utility for structural identification and functional characterization of whole GSLs present in the living cells/tissues.
3
Main text (1424 words).Cell surface GSLs exhibit various and crucial functions in cell growth, differentiation, adhesion, and malignant alteration 1 . It has been documented that dramatic changes in GSL composition and metabolism are strongly associated with oncogenic transformation 2,3 . Therefore, identification of disease-related structural alteration of cell surface GSLs will become a key to develop diagnostic biomarkers and therapeutic anticancer vaccines. However, purification and structural characterization of cellular GSLs have not been routinely possible to date, typically requiring tedious and time-consuming extraction/purification steps of GSLs of interest from extremely complex mixtures before analysis. In general, protocols for the isolation of GSLs would vary depending upon the analytical methods as well as chemical properties of individual GSLs and would need specialized expertise at step-by-step/case-by-case handling for separation. These crucial problems in the enrichment of whole GSLs make it difficult to achieve high throughput structural and functional analyses of biologically importantGSLs. In addition, we should pay attention to the fact that cell surface GSLs often exhibit specific biological functions through dynamic mechanism such as clustering or To illustrate the new method, crude lipids fraction 24 of C57BL/6JJcl adult (7 weeks) and embryonic (13.5 days) mouse brains were subjected directly to "ozonolysis" and "glycoblotting" protocol. Reaction of GSL-aldehydes with aoGNPs proceeded smoothly under mild condition without any special reagent. After simple purificationGSLs transferred onto aoGNPs (GSLs-GNPs) were employed directly for further structural characterization. The merit of this method is evident because whole procedure from GSLs enrichment to mass spectrometry-based structural profiling can be performed within 3~4 hours by employing approximately 100 mg (wet w...