MALDI-TOF/MS analysis of archaebacterial lipids in lyophilized membranes dry-mixed with 9-aminoacridine

• Main Authors: Roberto Angelini, Francesco Babudri, Simona Lobasso, Angela Corcelli
• Format: Article
• Language: English
• Published: Elsevier 2010-09-01
• Series: Journal of Lipid Research
• Subjects: glycerolipids (diphytanylglycerol ether analogs); glycerophospholipids (diphytanylglycerolphosphate ether analogs); Halobacterium salinarum; purple membrane; matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
• Online Access: http://www.sciencedirect.com/science/article/pii/S0022227520423120

A method of direct lipid analysis by MALDI mass spectrometry in intact membranes, without prior extraction/separation steps, is described. The purple membrane isolated from the extremely halophilic archaeon Halobacterium salinarum was selected as model membrane. Lyophilized purple membrane were grinded with 9-aminoacridine (9-AA) as dry matrix, and the powder mixture was crushed in a mechanical die press to form a thin pellet. Small pieces of the pellet were then attached to the MALDI target and directly analyzed. In parallel, individual archaebacterial phospholipids and glycolipids, together with the total lipid extract of the purple membrane, were analyzed by MALDI-TOF/MS using 9-AA as the matrix in solution. Results show that 9-AA represents a suitable matrix for the conventional MALDI-TOF/MS analysis of lipid extracts from archaeal microorganisms, as well as for fast and reliable direct dry lipid analysis of lyophilized archaebacterial membranes. This method might be of general application, offering the advantage of quickly gaining information about lipid components without disrupting or altering the membrane matrix.