Peptide Sequencing with Top-Down Synthesized TiO2 Nanowires Using Laser Desorption/Ionization Time-of-Flight Mass Spectrometry
Tae Gyeong Yun (1), Jong-Min Park (1), Joo-Yoon Noh (1), Moon-Ju Kim (1), Min-Jung Kang (2), Jae-Chul Pyun (1) (1) Yonsei University, Seoul, Republic of Korea, (2) Korea Institute of Science and Technology, Seoul, Republic of Korea
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Presenter Bio: Tae Gyeong Yun is an integrated course student in the Department of Materials Science and Engineering at Yonsei University. He received his B.S. degree in Materials Science and Engineering from Yonsei University in 2017. His research interests focused on nano-structured solid matrices to detect small molecules by MALDI-TOF mass spectroscopy for clinical diagnosis.
Relevant Financial Disclosures
(within past 24 months)
No relevant financial relationship(s) to disclose.
Abstract
Introduction : Peptide sequencing in mass spectrometry generally followed through tandem mass spectrometry with the collision-induced dissociation (CID) process, which uses accelerated noble gases for fragmentation. However, peptide sequencing with CID process is inadequate due to the requirement of expensive instrument and expert technicians. Recently titanium oxide (TiO2) nanowires for laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) was introduced with less background noises on low mass region. Moreover, its photocatalytic activity with UV due to the high band gap energy takes attention as a multifunctional solid matrix system.
Objective : Objective of this study is utilizing top-down synthesized TiO2 nanowires for both photocatalytic platform and matrix for LDI-TOF MS.
Methods : Top-down processed TiO2 nanowires were synthesized by modified wet-corrosion process with strong alkali treatment, mild agitation in DW, and heat treatment. Characterization change on surface morphology, phase transition, and photocatalytic activity for synthesized TiO2 nanowires was conducted on each step of processing. Peptide sequencing on six different peptide samples demonstrated by two steps; UV treatment of peptide samples on synthesized TiO2 nanowires by photocatalytic decomposition and LDI-TOF MS for fragment detection.
Results : Surface morphology of synthesized TiO2 nanowires was observed by scanning electron microscope (SEM) and atomic force microscope (AFM). Crystal structure of synthesized TiO2 nanowires was identified as the mixture of anatase and lepidocrocite phases by X-ray diffraction (XRD). The photocatalytic activity of synthesized TiO2 nanowires demonstrated with methylene blue reaction by comparing the commercial TiO2 nanoparticles (P25). Six peptide samples were analyzed to obtain the serial fragment sequences. Three peptides (9, 13, 15 amino acids, respectively.) were analyzed and expected ion forms were suggested. Total serial fragments are observed so the identification on full sequence of parent peptide enabled. Three peptides in identical molecular weights with different amino acid sequences were designed to estimate the performance of synthesized TiO2 nanowire platform. Entire sequence of target peptides was fully distinguished from each and the other by gathering multiple mass spectra results into single screen.
Conclusion : Sequencing six different peptides was conducted through a top-down synthesized TiO2 nanowire solid matrix with LDI-TOF MS after simple UV treatment. Mass peaks from several sample spectra combined and the complete amino acid sequences obtained. Moreover, peptides with identical molecular weights can be distinguished by proposed method.
= Discovery stage.
= Translation stage.
= Clinically available.
