BMAA detected as neither free nor protein bound amino acid in blue mussels. (January 2016)

• Record Type: Journal Article
• Authors: Rosén, Johan; Westerberg, Erik; Schmiedt, Sebastian; Hellenäs, Karl-Erik
• Is Part Of: Toxicon. Volume 109(2016)
• Page Start: 45
• Page End: 50
• Publication Date: 2016-01
• Subjects: BMAA -- Analysis -- Extraction -- Mussels -- Neurodegenerative disease -- HILIC–UHPLC–MS/MS; Toxins -- Periodicals; Venom -- Periodicals; 615.9
• DOI: 10.1016/j.toxicon.2015.11.008
• Languages: English
• ISSNs: 0041-0101

Abstract

Abstract: The results of this study imply that β-methylamino-alanine (BMAA) obtained from extracts of blue mussels from the Swedish west coast is neither free nor protein bound. The results were obtained by separation (precipitation and ultrafiltration) of low and high molecular weight compounds from neutral extracts of blue mussels, and treatment of these extracts with low and high concentrations of acids, varying time and temperature. The main portion of BMAA was obtained from the low molecular weight fraction, released or formed at 95 °C in dilute acids. The measured amount of BMAA did not increase by strong acid treatment. Lysine was used as reference and was only released at significant amounts when treating the high molecular weight fraction with concentrated acid. The results also indicated that breakage of peptide bonds was not involved in the formation/release of BMAA in these extracts unless any BMAA peptide bond would be significantly more susceptible to dilute acid than e.g. the monitored lysine peptide bond. BMAA was measured using isotope dilution and detection of the underivatized compound by HILIC–UHPLC–MS/MS (Hydrophilic Interaction Liquid Chromatography, Ultra-High Performance Liquid Chromatography, tandem Mass Spectrometry). The findings might add to the understanding of conflicting data in the literature regarding the occurrence of BMAA, and have implications for studies on possible biomagnification of BMAA in the food chain and bioavailability from food. Highlights: BMAA extracted from blue mussels was neither as the free amino acid nor protein bound. BMAA was formed or released from the low molecular weight fraction of blue mussels. The BMAA was formed at conditions similar to established extraction protocols. The formation/release of BMAA did not seem to involve breakage of peptide bonds. The findings might give a clue to earlier reported diverging data on BMAA levels.