TABLE 4

Accurate masses of truncated (pegylated) peptide metabolites of MRL-1 identified in vivo

Truncated peptide was cleaved from PEG in each metabolite using a chemical procedure and analyzed by LC-MS.

MRL-1 Peptide and MetabolitesSequenceaCalculated Exact MassMonoisotopic m/zMass Error
CalculatedObserved
Dappm
1-26CFRVDEEFQS PFASQSRGYF LFRPRN-NH23189.5533798.3956 (4+), 1064.1917 (3+)798.3919 (4+)5
1-25CFRVDEEFQS PFASQSRGYF LFRPR-OH3076.4944770.1309 (4+), 1026.5054 (5+)770.1314 (4+), 1026.5060 (3+)1
1-20CFRVDEEFQS PFASQSRGYF-OH2407.0869803.3696 (3+), 1204.5507 (2+)803.3700 (3+), 1204.5518 (2+)<1
1-18CFRVDEEFQS PFASQSRG-OH2096.9552699.9923 (3+), 1049.4848 (2+)699.9921 (3+), 1049.4851 (3+)<1
1-17CFRVDEEFQS PFASQSR-OH2039.9337680.9852 (3+), 1020.9741 (2+)680.9853 (3+), 1020.9744 (3+)1
1-16CFRVDEEFQS PFASQS-OH1883.8326628.9515 (3+), 942.9236 (2+)628.9513 (3+), 942.9240 (2+)<1
1-15CFRVDEEFQS PFASQ-OH1796.8006599.9408 (3+), 899.4076 (2+)599.9409 (3+), 899.4079 (2+)<1
1-13CFRVDEEFQS PFA-OH1581.7080528.2439 (3+), 791.8623 (2+)791.8624 (2+)<1
1-12CFRVDEEFQS PF-OH1510.6729504.5649 (3+), 756.3437 (4+)756.3437 (2+)<1
  • a Amino acid C in each sequence refers to modified cysteine as shown in Fig. 7.