Purification of HC2·TSG-6 complex. Pool 2, containing the
HC2·TSG-6 complex, from the strong cation exchange-HPLC analysis was
subjected to RP-HPLC analysis directly (A) or after treatment with
NaOH (B). The asterisk-labeled peak contains a non-peptide
derived contamination. C, MALDI-TOF MS analysis of peak γ from
RP-HPLC analysis of the untreated pool 2 (panel A) shows that the
peak contains the HC2·TSG-6 complex (theoretical monoisotopic
MH+: m/z 1943.91). D, MALDI-TOF MS
analysis of peak λ from RP-HPLC of the NaOH treated pool 2 (panel
B) shows that the peak contains the tryptic TSG-6 peptide
(22DGIFHNSIWLER33, theoretical monoisotopic
MH+: m/z 1486.73), which participates in the
cross-link. The analyses demonstrate that HC2·TSG-6
(645VEND648 cross-linked to
22DGIFHNSIWLER33) has been purified and is present in
peak γ.