Fig. 3.

Combining MS of protein assemblies with CXMS. A, mass spectrometry of intact complexes reveals the stoichiometry of the intact AKAP complex: 2 × [AKAP79 + PP2B (A+B) + 2RII D/D + CaM] and demonstrates the dimerization of AKAP 79. B and C, confirmation of the AKAP dimer by chemical cross-linking and MS also suggests that the dimer is aligned in parallel. D, a proposed model for the architecture and dynamics of the core AKAP79 signaling complex, in conditions of both high and low [Ca²⁺]. The second AKAP79 monomer and associated proteins are in the background. These figures are reproduced from Ref. 104 with permission.