MALDI-TOF/MS analysis of archaebacterial lipids in lyophilized membranes dry-mixed with 9-aminoacridine.
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.
Department of Medical Biochemistry, Biology and Physics, University of Bari Aldo Moro, Italy.
Roberto
R
Angelini
Francesco
F
Babudri
Simona
S
Lobasso
Angela
A
Corcelli
D000585:Aminacrine / Q000737:chemistry*; D001105:Archaea / Q000737:chemistry / Q000648:ultrastructure; D005456:Fluorescent Dyes / Q000737:chemistry*; D005612:Freeze Drying; D019617:Halobacterium salinarum / Q000737:chemistry / Q000648:ultrastructure; D008055:Lipids / Q000032:analysis*; D015394:Molecular Structure; D018717:Purple Membrane / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D005456:Fluorescent Dyes; D008055:Lipids; D000585:Aminacrine