Biogenic amines analysis results

As a result of a high index of clinical suspicion and, on occasion, supporting biochemical data from other investigations, one of the first specialist investigations to ascertain whether a patient has an inborn error of biogenic amine metabolism is, as mentioned above, analysis of the CSF concentrations of HVA and 5HIAA. This is often performed in conjunction with the measurement of 3-methyldopa (3-MD), also known as 3-methoxytyrosine. 3-MD is formed from L-dopa via COMT activity and accumulates in conditions where aromatic amino acid decarboxylase activity is impaired. The chemical structures of HVA, 5HIAA and 3-MD are shown in Fig. 6.2.1. 

Some examples of studies with MALDI and IMS include the use of MALDI to generate sodiated parent ions of a number of oligosaccharides without fragmentation and cationized forms of bradykinin. Cross sections of the ions were obtained and compared with predictions made by molecular mechanics or molecular dynamics calculations. Comparison of MALDI/IM/TOF-MS with MALDI/IM/MS analysis yielded results similar to that by nanoelectrospray MS. Dipeptides and biogenic amines were analyzed with a system that consisted of an atmospheric pressure MALDI source, an IMS, and an orthogonal TOF-MS, and sensitivity was improved when a localized CD source was added. ... 

Future trends in the separation area will include translation of all these methods to microchip format, which promises to lead the next revolution in chemical analysis. MEKC and isotachophoresis, a CE separation technique in a discontinuous buffer system, have already been adapted to microchips and applied to assay herbicides, biogenic amines, and ions. Micro-channels on a chip-like structure are likely to be exploited more frequently in CE after further development of nanotechnology because it results in extremely rapid separations that consume only picoliter sample volumes and introduce the possibility of merging sample preparation and analysis in a single device. 

A considerable body of results accumulated during earlier decades from activity studies of hCp now awaits a more meaningful analysis using the available 3D structure. Catalysis of amine oxidation by hCp, in particular biogenic ones present in plasma, cerebral, spinal, and intestinal fluids as well as of ferrous ions, which is probably physiologically relevant, has been studied extensively (68, 71). The mechanism of dioxygen reduction by hCp at the trinuclear center is of particular interest, as the presence of three distinct Tl sites raises the question of which centers are involved in internal ET to the single O2 reduction site. This mechanistic question prompted us to initiate ET studies by PR. 

---