Desorption/ionization on silicon (DIOS): a diverse mass spectrometry platform for protein characterization.
Since the advent of matrix-assisted laser desorption/ionization and electrospray ionization, mass spectrometry has played an increasingly important role in protein functional characterization, identification, and structural analysis. Expanding this role, desorption/ionization on silicon (DIOS) is a new approach that allows for the analysis of proteins and related small molecules. Despite the absence of matrix, DIOS-MS yields little or no fragmentation and is relatively tolerant of moderate amounts of contaminants commonly found in biological samples. Here, functional assays were performed on an esterase, a glycosidase, a lipase, as well as exo- and endoproteases by using enzyme-specific substrates. Enzyme activity also was monitored in the presence of inhibitors, successfully demonstrating the ability of DIOS to be used as an inhibitor screen. Because DIOS is a matrix-free desorption technique, it also can be used as a platform for multiple analyses to be performed on the same protein. This unique advantage was demonstrated with acetylcholine esterase for qualitative and quantitative characterization and also by its subsequent identification directly from the DIOS platform.
Thomas
J J
JJ
Departments of Chemistry and Molecular Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Shen
Z
Z
Crowell
J E
JE
Finn
M G
MG
Siuzdak
G
G
D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000737:chemistry / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D019992:Databases as Topic; D004791:Enzyme Inhibitors / Q000032:analysis / Q000494:pharmacology; D004798:Enzymes / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008246:Lysophospholipids / Q000378:metabolism; D008361:Mannosidases / Q000737:chemistry / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010449:Peptide Mapping; D010713:Phosphatidylcholines / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism; D016062:Porosity; D020543:Proteome; D020539:Sequence Analysis, Protein; D012825:Silicon / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013329:Structure-Activity Relationship; D014357:Trypsin / Q000378:metabolism
D004791:Enzyme Inhibitors; D004798:Enzymes; D008246:Lysophospholipids; D010446:Peptide Fragments; D010713:Phosphatidylcholines; D020543:Proteome; D010740:Phospholipases; D000110:Acetylcholinesterase; D008361:Mannosidases; C038829:mannosyl-oligosaccharide 1,3 - 1,6-alpha-mannosidase; D014357:Trypsin; D002794:Choline; D000109:Acetylcholine; D012825:Silicon