The matrix is a mixture of dihidroxy-benzoic acid and methoxy-salicylic acid.
Each component is dissolved in 0.1% TFA/H2O, MeCN (2:1), at 20mg/ml. The two
solutions are then mixed 9:1 (respectively). It was cited as a matrix for
branched triple-helical peptides. These peptides have been historically
difficult to ionize due to the covalent branch. I don't know if it will work for
your seemingly uncharged peptide, but it's fairly easy to try.
We've found the matrix to be widely applicable. I've had especially good luck
using it with enzymatic cleavage products that are in difficult buffers
(tris/tricine, salts, detergents).
Good luck,
Jeni
Janelle Lauer-Fields
Department of Chemistry & Biochemistry
Florida Atlantic University
777 Glades Road
Boca Raton, Florida 33431
561-297-2094/Fax 561-297-2759