Dimerization of Peptides by Calcium Ions: Investigation of a Calcium-Binding Motif

Figure 1

(a) ESI-ion trap (direct infusion) mass spectrum of GTGDEG in the presence of Ca²⁺. (b) Insert showing peaks for P⋯Ca²⁺⋯P (doubly charged) at 554.2 and for P⋯Na⁺ at 557.2 (singly charged).

(a)

(b)