Table 3.

Peptide contents of the tryptic digest of αs2-casein

Peptide sequenceRetention time (min)Molecular mass (Da)pIT 50% (h)a
YQK15.3437.310.111.89
ISQR15.7502.311.314.19
HYQK15.7574.310.314.19
EVVR18.9501.311.316.42
LTEEEK19.4747.44.116.42
TVYQHQKb 20.9902.510.312.51
EQLZTZEENSKKc 20.91,538.64.7 NDd
ITVDDK23.7689.4414.56
YL26.7294.26.15.70
NMAINPSK27.5873.510.412.29
NANEEEYSIGZZZEEZAEVATEEVKb 33.23,007.13.9 NCe
AM*KPWIQPKc 33.21,11410.9ND
VIPYb 33.8490.3615.14
PWIQPKc 33.8767.510.4ND
KNTMEHVZZZEESIIZQETYKQEKb 35.13,132.34.5NC
KNTMEHVZZZEESIIZQETYKb 35.12,747.14.4NC
TVDMESTEVFTKKc 35.11,593.44.5NC
TVDMEZTEVFTKKb 35.81,465.63.9NC
LNFLKKb 35.8761.510.910.89
RNAVPITPTLNRc 35.81,350.812.6ND
NAVPITPTLNR36.31,194.711.313.57
AMKPWIQPK36.91,097.610.912.19
LNFLK38.6633.410.410.43
ALNEINQFYQK39.61,366.77.113.55
NMAINPZKENLCSTFCK41.81,977.68.318.13
FPQYLQY43.6957.5613.0
FALPQYLK45.5978.61011.63
LYQGPIVLNPWDQVK50.11,7698.614.56
FPQYLQYLYQGPIVLNPWDQVK59.72,708.4814.95
  • a Time at which 50% of the peptide was consumed by L. lactis MG1363 during growth in CDM containing a tryptic digest of αs2-casein as the nitrogen source.

  • b Major coeluting peptide.

  • c Minor coeluting peptide. M*, oxidized methionine. Z, phosphoserine.

  • d ND, not detectable.

  • e NC, no consumption.