Characterization of a New Immunosuppressive and Antimicrobial Peptide, DRS-DA2, Isolated from the Mexican Frog, Pachymedusa dacnicolor

Figure 1

Isolation and purification of a new immunosuppressor peptide, dermaseptin DRS-DA2. (a) Fraction I that was shown to induce the death of leukocytes was purified by RP-HPLC. Among all the fractions tested for an immunosuppressive effect, the one with a retention time of 49 min (arrow) induced the death of leukocytes. (b) De novo characterization by MALDI-TOF/TOF mass spectrometry identified three peptides in fraction 49: DRS-DA2NEQ, DRS-DA2NE, and DRS-DA2N. Those peptides were all carboxylated at their C-terminus. Isotopic masses are given for the protonated molecules, and mass errors are given in ppm. The sequence of the nontruncated peptide corresponds to PD-2-2.

(a)

(b)