Chemical cross-linking coupled to mass spectrometry was used to study the complex between the ribosomal protein, eS26A, and the escortin, Tsr2. Cross-linking was performed using different cross-linking chemistries: (1) disuccinimidyl suberate (DSS); (2) a combination of adipic acid dihydrazide (ADH) and the coupling reagent, DMTMM; (3) a combination of pimelic acid dihydrazide (PDH) and the coupling reagent, DMTMM.