Table III

Posttranslational modification of mono-, di-, and trimethylation of human hair proteins identified from the insoluble fraction

Three cLC-MS/MS data sets from insoluble fractions were re-searched against 343 identified proteins with possible ubiquitination (+114 on Lys), methylation (+14 on Lys, Arg, His), trimethylation/acetylation and dimethylation (+42 on Lys, +28 on Lys, Arg), and phosphorylation (+80 on Ser, Thr, Tyr). Very tight criteria were used (fully tryptic peptides, no missed cleavage except modified Lys or Arg, Xcorr ≥ 1.9, 2.2, and 3.75 for +1, +2, and +3 ions, respectively) and manually validated with high standards (No unassignable significant intensity peaks were allowed, and most y and b series ions should be identified.). Observed modifications on amino acids are denoted with the following superscript symbols: m, methylation (+14 Da); dm, dimethylation (+28 Da); tm, trimethylation/acetylation (+42 Da) (This assignment is tentative because it cannot be distinguished from acetylation (+42 Da), and also the possibility of carbamylation cannot be totally eliminated.); ox, oxidation (+16 Da). Bold indicates posttranslationally modified amino acid residues.

ProteinSampleaMS/MSbSequencecXcorrzd
Calmodulin-like 312R.LGEKmLSDEEVDEMIR.A3.69392
11R.LGEKmLSDEEVDEMoxIR.A2.87932
Desmoplakin11R.IQESKdmNQCTQVVQER.E4.39512
Sialidase 211R.ADLGAYLNPRmPPAPEAWSEPVLLAK.A3.99753
Actin, cytoplasmic 134K.YPIEHmGIVTNWDDMEK.I4.58292
11K.YPIEHmGIVTNWDDMoxEK.I4.0042
Similar to RIKEN cDNA 4732495G21 (actine)22K.YPIEHmGVVTNWDDMEK.I4.29962
H1, 511R.KdmATGPPVSELITK.A3.03292
H2B, Q22K.VLKdmQVHPDTGISSK.A3.65882
22R.LLLPGELAKdmHAVSEGTK.A3.87782
H311R.VTIMPKmDIQLAR.R2.26062
26R.EIAQDFKdmTDLR.F2.86442
11R.VTIMoxPKdmDIQLAR.R2.51162
HIST1H4F14R.DNIQGITKmPAIR.R3.04342
16R.GVLKmVFLENVIR.D3.85192
16R.DNIQGITKdmPAIR.R3.50922
211R.GVLKdmVFLENVIR.D4.3652
Keratin, I, HA211R.LASYLTRdmVR.Q2.2362
Keratin, II, HB212R.FASFINKdmVR.F2.91242
11K.KdmYEEELSLRPCVENEFVALK.K3.91683
12R.LQQETENVKdmAQR.3.50132
24R.LQQETENVK™AQR.C3.65632
Keratin, II, HB622K.KdmYEEEVSLR.A3.10152
11R.KdmSDLEANVEALIQEIDFLR.R5.33062
11K.LAELEGALQKdmAK.Q3.66072
  • a Number of samples where the peptides were found.

  • b Number of MS/MS spectra observed for the sequences.

  • c Amino acids at N-terminal and C-terminal side of the peptide sequences are also shown before and after dots.

  • d Charge state of peptide ions.

  • e ProSite prediction of protein families and domains for uncharacterized proteins translated from genomic or cDNA sequences (us.expasy.org/prosite/).