New approach for glyco- and lipidomics--molecular scanning of human brain gangliosides by TLC-Blot and MALDI-QIT-TOF MS.

We have developed a TLC-Blot system that makes possible the direct analysis of blotted glycosphingolipids on a polyvinylidene difluoride membrane from a high-performance TLC plate by immunological staining, chemical staining, enzymatic treatment and mass spectrometric (MS) analysis. An ion trap type matrix-assisted laser desorption/ionization-quadrupole ion trap-time of flight (MALDI-QIT-TOF) MS apparatus improved not only the molecular identification but also the analysis of molecular species of lipids on the polyvinylidene difluoride membrane. A new approach for glyco- and lipidomics, molecular scanning technology by a combination of TLC-Blot and MALDI-QIT-TOF MS, was developed and applied to human brain gangliosides separated from the tissues of patients with neural diseases and control patients. The results clearly showed a change of ganglioside composition, in addition to identifying individual ganglioside molecular species, in the hippocampus gray matter of patients with Alzheimer's disease. The results strongly suggested that metabolic changes of gangliosides played an important role in the progression of this disease. The present technology with molecular imaging should provide valuable information for elucidating the significance of molecular species in neuronal functions such as neural transmission, memory, and learning.