Direct Evidence of Methylglucose Lipopolysaccharides/Palmitoyl-CoA Noncovalent Complexes by Capillary Zone Electrophoresis−Electrospray/Mass Spectrometry

• Published in: Analytical chemistry (Washington) Vol. 70; no. 9; pp. 1853 - 1858
• Main Authors: Tuffal, Gilles, Tuong, Anne, Dhers, Christiane, Uzabiaga, Françoise, Rivière, Michel, Picard, Claudine, Puzo, Germain
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.05.1998
• Subjects: Analytical chemistry; Analytical, structural and metabolic biochemistry; Bacteria; Biochemistry; Biological and medical sciences; Carbohydrates; Chemical reactions; Chemistry; Electrophoresis, Capillary; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General, instrumentation; Glucose; Lipopolysaccharides - analysis; Mass Spectrometry; Methylglucosides - analysis; Organic chemistry; Oses; Other biological molecules; Palmitoyl Coenzyme A - analysis; Ultraviolet radiation; Analysis method; Mycobacteriales; Gel electrophoresis; Mycobacteriaceae; Lipopolysaccharide; Mycobacterium smegmatis; Bacteria; Actinomycetes; Molecular complex; Mass spectrometry
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac971101r

Mycobacterial methylglucose lipopolysaccharides (MGLPs) play an important regulatory role in the biosynthesis of long-chain fatty acids by forming complexes with neosynthesized acyl-CoA fatty acid derivatives. The MGLPs from Mycobacterium smegmatis were purified by high-performance anion-exchange chromatography and characterized by LSIMS and CE/ESI-MS. We investigated their interaction with palmitoyl-CoA using capillary zone electrophoresis with both direct and indirect UV detection. In the latter mode, the signal of the UV-transparent MGLPs decreased upon addition of increasing amounts of palmitoyl-CoA; while using direct UV detection, the addition of palmitoyl-CoA to the MGLPs revealed characteristic profiles. The major peak was assigned to the noncovalent MGLP/palmitoyl-CoA complex on the basis of its electrophoretic mobility. The abundance of the complex was found to increase until the MGLP/palmitoyl-CoA molar ratio reached a 1/1 stoichiometry. The existence of and the stoichiometry of this complex were assessed by CE/ESI mass spectrum analysis, showing pseudomolecular ions of the MGLP/palmitoyl-CoA complex. These results confirm that CE/ESI-MS is a powerful tool to characterize noncovalent molecular association.