Applying Magnetic Bead Separation / MALDI-TOF Mass Spectrometry to Human
Tear Fluid Proteome Analysis |
Eiichi Sekiyama, Yumiko Matsuyama, Daisuke Higo, Takashi Nirasawa,
Masaya Ikegawa, Shigeru Kinoshita, and Kei Tashiro |
| Abstract |
The proteins and peptides in tears play an important role in
preserving the integrity and stability of the ocular surface.
Proteomic analysis of tear films will enable us to detect
early biological markers of eye diseases, however, it is often
hampered by the small amount of tear volume and the low
protein concentration. Here we adopted magnetic beadbased
purification (ClinProt system) followed by matrixassisted
laser desorption/ionization time-of-flight mass
spectrometry (MALDI-TOF-MS) to profile human tear
proteins. Basal and reflex tear fluids were collected from
normal healthy volunteers using glass microcapillary tubes.
Reversed phase (C8) and weak cation exchange (WCX)
magnetic beads were applied to obtain multiple components
detected as clear signals. Principal component analysis
showed a clear differentiation between basal and reflex tears.
Among the key alterations, two markedly increased peaks
in the reflex tear fluids at m/z 2422.12 and m/z 2721.29
were subsequently analyzed by tandem MS analysis and
their source to be proline-rich protein 4 (PRP4). We conclude
that magnetic bead-based separation combined with
MALDI-TOF-MS (ClinProt MALDI-TOF) appears to be
ideally suited for the first-line screening of peptides and
proteins in tears. |
|
|
This Artical |