Table I

Quantitative analysis of standard protein mixture using the SoPIL reagents

Protein namePeptide sequenceaObserved ratiobMean ± S.D.Expected ratioError
%
Bovine serum albuminK↓TC*VADESHAGC*EK↓S1.33 ± 0.221.19 ± 0.221.019
F↓HADIC*TLPDTEK↓Q1.03 ± 0.14
K↓YIC*DNQDTISSK↓L1.17 ± 0.2
R↓NEC*FLSHKDDSPDLPK↓L1.44 ± 0.51
K↓DDPHAC*YSTVFDK↓L1.29 ± 0.24
K↓EAC*FAVEGPK↓L1.18 ± 0.16
K↓LKEC*C*DKPLLEK↓S1.61 ± 0.07
R↓ETYGDMADC*C*EK↓Q1.32 ± 0.21
K↓SLHTLFGDELC*K↓V0.88 ± 0.15
K↓EYEATLEEC*C*AK↓D1.12 ± 0.17
K↓SLHTLFGDELC*K↓V0.88 ± 0.15
K↓YNGVFQEC*C*QAEDK↓G1.48 ± 0.22
K↓LFTFHADIC*TLPDTEK↓Q1.15 ± 0.14
K↓EC*C*HGDLLEC*ADDRADLAK↓Y1.02 ± 0.54
β-LactoglobulinL↓SFNPTQLEEQC*HI↓–0.62 ± 0.080.52 ± 0.110.54
R↓LSFNPTQLEEQC*HI↓–0.46 ± 0.08
F↓C*MENSAEPEQSLAC*QC*LVR↓T0.47 ± 0.06
α-LactalbuminK↓FLDDDLTDDIMC*VK↓K1.9 ± 0.782.15 ± 0.432.08
K↓DDQNPHSSNIC*NISC*DK↓F2.74 ± 0.56
H↓SSNIC*NISC*DK↓F1.82 ± 0.19
Lysozyme CL↓LSSDITASVNC*AK↓K0.99 ± 0.151.07 ± 0.121.07
C↓SALLSSDITASVNC*AK↓K1.16 ± 0.3
R↓NLC*NIPC*SALLSSDITASVNC*AK↓K0.94 ± 0.15
R↓C*ELAAAMK↓R1.22 ± 0.05
  • a ↓ indicates a tryptic cleavage site; dash indicates a carboxyl-terminal residue. * indicates the modification of Cys residue by SoPIL reagents.

  • b Ratios (12C6/13C6) and errors were calculated using the open source ASAPRatio program.