Identification and affinity-quantification of ß-amyloid and α-synuclein polypeptides using on-line SAW-biosensor-mass spectrometry.
Bioaffinity analysis using a variety of biosensors has become an established tool for detection and quantification of biomolecular interactions. Biosensors, however, are generally limited by the lack of chemical structure information of affinity-bound ligands. On-line bioaffinity-mass spectrometry using a surface-acoustic wave biosensor (SAW-MS) is a new combination providing the simultaneous affinity detection, quantification, and mass spectrometric structural characterization of ligands. We describe here an on-line SAW-MS combination for direct identification and affinity determination, using a new interface for MS of the affinity-isolated ligand eluate. Key element of the SAW-MS combination is a microfluidic interface that integrates affinity-isolation on a gold chip, in-situ sample concentration, and desalting with a microcolumn for MS of the ligand eluate from the biosensor. Suitable MS-acquisition software has been developed that provides coupling of the SAW-MS interface to a Bruker Daltonics ion trap-MS, FTICR-MS, and Waters Synapt-QTOF- MS systems. Applications are presented for mass spectrometric identifications and affinity (K(D)) determinations of the neurodegenerative polypeptides, ß-amyloid (Aß), and pathophysiological and physiological synucleins (α- and ß-synucleins), two key polypeptide systems for Alzheimer's disease and Parkinson's disease, respectively. Moreover, first in vivo applications of αSyn polypeptides from brain homogenate show the feasibility of on-line affinity-MS to the direct analysis of biological material. These results demonstrate on-line SAW-bioaffinity-MS as a powerful tool for structural and quantitative analysis of biopolymer interactions.
Laboratory of Analytical Chemistry and Steinbeis Center for Biopolymer Structure Analysis, University of Konstanz, 78457, Konstanz, Germany.
Stefan
S
Slamnoiu
Camelia
C
Vlad
Mihaela
M
Stumbaum
Adrian
A
Moise
Kathrin
K
Lindner
Nicole
N
Engel
Mar
M
Vilanova
Mireia
M
Diaz
Christiaan
C
Karreman
Marcel
M
Leist
Thomas
T
Ciossek
Bastian
B
Hengerer
Marta
M
Vilaseca
Michael
M
Przybylski
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D016229:Amyloid beta-Peptides / Q000032:analysis* / Q000737:chemistry / Q000528:radiation effects; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D000915:Antibody Affinity; D015374:Biosensing Techniques; D001921:Brain / Q000378:metabolism; D017357:Cyclotrons; D000939:Epitopes; D005240:Feasibility Studies; D005583:Fourier Analysis; D006801:Humans; D013058:Mass Spectrometry; D008822:Mice, Transgenic; D046210:Microfluidic Analytical Techniques; D008970:Molecular Weight; D050505:Mutant Proteins / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects; D009474:Neurons / Q000737:chemistry; D011994:Recombinant Proteins / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects; D013016:Sound; D051844:alpha-Synuclein / Q000032:analysis* / Q000737:chemistry / Q000235:genetics / Q000528:radiation effects
D016229:Amyloid beta-Peptides; D000911:Antibodies, Monoclonal; D000939:Epitopes; D050505:Mutant Proteins; D011994:Recombinant Proteins; C497604:SNCA protein, human; D051844:alpha-Synuclein