maenas (intertidal zone) and Segonzacia mesatlantica - Station ...

124 CHAPITRE 3. STRUCTURE DE L’HC DE C. MAENAS PAR ESI-MS
FIG. 3.8 – Alkaline dissociation and acidic reassociation of Carcinus maenas hemocyanin coupled with chelation of
divalent cations by EDTA. Whole hemolymph sample was washed by an EDTA mix (pH 9) as explained in the materials
and methods section and salts were then removed by washing with 10 mM AcNH4 containing TEA at various concentrations.
Left part, whole mass spectra, right part, focus in the monomer peaks m/z range. Spectra were acquired as follow :
first spectrum, washing with 0.05 % TEA (pH 9.02) ; second spectrum, washing with 0.005 % TEA (pH 7.52) ; third
spectrum, washing with 0.05 % TEA and addition of 2 mM lactic acid (pH 8.09) ; fourth spectrum, washing with 0.005 %
TEA and addition of 2 mM lactic acid (pH 7.35). m, monomers peaks, h, hexamer peaks (450 kDa), d, dodecamer peaks
(900 kDa), dl, light dodecamer peaks (885 kDa). On the third spectrum (pH 8.09, 2mM lactate), the hexamer peaks could
correspond to a classical hexamer and to a "light" hexamer.