Screening for phosphorylated and nonphosphorylated peptides by infrared photodissociation spectroscopy.
We present an infrared laser-based mass spectrometric strategy to differentiate peptides that are phosphorylated (i.e., containing pS, pT, or pY) from those that are nonphosphorylated (i.e., containing S, T, or Y), and those peptides that have none of these moieties (i.e., containing neither pS, pT, pY nor S, T, Y). This is demonstrated for a series of tripeptides and for two larger octapeptides, showing that the diagnostic phosphate OH stretch (indicative for pS, pT, or pY) can be distinguished from the alcohol OH stretch (indicative for S, T, or Y). In addition, the infrared multiple photon dissociation (IRMPD) spectra of multiple peptide analytes are recorded simultaneously in a multiplexed fashion. This is achieved by complexing each peptide precursor with a noncovalently bound 18-crown-6 ether, which is detached upon resonant infrared photon absorption.
Department of Chemistry, University of Florida, Post Office Box 117200, Gainesville, Florida 32611, United States.
Corey N
CN
Stedwell
Amanda L
AL
Patrick
Kerim
K
Gulyuz
Nicolas C
NC
Polfer
D000438:Alcohols / Q000737:chemistry; D000595:Amino Acid Sequence; D001665:Binding Sites; D008970:Molecular Weight; D010710:Phosphates / Q000737:chemistry; D010748:Phosphopeptides / Q000032:analysis* / Q000737:chemistry*; D010766:Phosphorylation; D013055:Spectrophotometry, Infrared / Q000379:methods*
D000438:Alcohols; D010710:Phosphates; D010748:Phosphopeptides