1. Supplementary material Fig. I: Screening of venom-gel fractions (GF) for ACEi by conventional HPLC-UV method. The inhibitory effiency (IE) calculated by dividing the slope of AI (left) consumption and AII (right) formation in presence of the GF by the slope observed in a blank assay. A reduced slope of the reaction speed indicates the presence of ACEi in the GF.

2. Supplementary material Fig. II: Application of the TFC column to extract peptides from snake-venom fractions 14-15. A: Loading of the GF fraction onto the TFC column. B: Afterwards, the retained components were eluted onto an RP column and separated by a gradient from binary pump B and detected by ESI-MS. auto sampler ESI-MS waste Pump A Pump B analytical column auto sampler ESI-MSESI-MS waste Pump A pump A Pump Bpump B analytical column auto sampler ESI-MS waste Pump A Pump B analytical column auto sampler ESI-MSESI-MS waste Pump A pump A Pump B pump B analytical column TFC AB

3. Supplementary Material Fig. III: XIC chromatograms of the RP separation of the peptides extracted venom fraction 14 (black) and 15 (grey).

4. Supplementary Material Fig. IV: ESI-MS-Spectra of the fractions of peak C (top) and peak D+E (below) and their effect on the ACE-reaction plots in in the TFC-ESI-MS based method. The dotted line represents the ACE conversion of the blank assay (without inhibitor) peak C peak D+E

5. Supplementary Material Fig. V: De-novo sequencing of peptide C by nano-ESI(+)-FTICR-MS/MS. Product ions result from collision-induced dissociation of the [M+H] + (displayed) and [M+2H] 2+ ion of the peptide. The deduced sequence is indicated on the top the spectrum together with b- and y-ions attribution. Please note that fragments that were only detected in the linear ion-trap part of the instrument are labelled with an asterisk. (IF, internal fragment)

6. Supplementary Material Fig. VI: De-novo sequencing of peptide D by nano-ESI(+)-FTICR-MS/MS. Product ions result from collision-induced dissociation of the [M+2H] 2+ ion of the peptide. The deduced sequence is indicated on the top the spectrum together with b- and y-ions attribution. Please note that fragments that were only detected in the linear ion-trap part of the instrument are labelled with an asterisk.