Use of 1,5-diaminonaphthalene to combine MALDI-In-Source Decay fragmentation
with Hydrogen/Deuterium Exchange
Pascale Lemaire1, Delphine Debois1, Nicolas Smargiasso1, Loïc Quinton1,
Valérie Gabelica2 and Edwin De Pauw1*
1
GIGA-R, Mass Spectrometry Laboratory, Department of Chemistry, Chemistry Building B6c
University of Liège, B-4000 Liège, Belgium.
2
IECB, ARNA Laboratory,
University of Bordeaux, F-33600 Pessac, France.
Supporting Information
Figure S1. Microscope pictures of matrix crystals for 2,5-DHB (a), 1,5-DAN (b), SA (c) and
4-HCCA (d) matrices which was prepared in 50:50 acetonitrile/0.1% aqueous TFA.
Photographs have been taken using a binocular connected to a Moticam with an enlarging of
2.5×.
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Figure S2. Microscope pictures of matrix crystals for 2,5-DHB (a), 1,5-DAN (b), SA (c) and
4-HCCA (d) matrices which was prepared in 50:50 acetonitrile/D2O (0.1% deuterated TFA).
Photographs have been taken using a binocular connected to a Moticam with an enlarging of
2.5×.
Figure S3A. Residual deuterons in cn- ions coming from MALDI-ISD fragmentation of
native ubiquitin which has back-exchanged deuterons for hydrogens during 92 minutes at
20°C. Results for positive reflector mode (blue diamonds) and positive linear mode (red
squares). The instrument laser shot frequency was set up to 66.7 and 200 Hz respectively in
positive reflector and positive linear mode. 10.000 laser shots were accumulated in the 50010.000 m/z range on each MALDI spot.
2
Figure S3B. Residual deuterons in zn- ions coming from MALDI-ISD fragmentation of
native ubiquitin which has back-exchanged deuterons for hydrogens during 92 minutes at
20°C. Results for positive reflector mode (blue diamonds) and positive linear mode (red
squares). The instrument laser shot frequency was set up to 66.7 and 200 Hz respectively in
positive reflector and positive linear mode. 10.000 laser shots were accumulated in the 50010.000 m/z range on each MALDI spot.
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Figure S4. Circular dichroism spectra of β-endorphin in 100 mM deuterated ammonium
acetate solution (red squares) and in 50:50 100 mM deuterated ammonium acetate/CD3OD
solution (green circles).
Figure S5. MALDI MS mass spectra overlay of the non deuterated molecular parent ion in
100 mM ammonium acetate solution (black), the deuterated molecular parent ion in 100 mM
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deuterated ammonium acetate solution (red) and the deuterated molecular parent ion in 50:50
100 mM deuterated ammonium acetate/CD3OD solution (green) that have back-exchanged
deuterons for hydrogens during 1 minute.
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