Comparisons of BSA cross-link data by the three SDASO linkers. Comparisons of (A) cross-linked peptide sequences and (B) residue-to-residue linkages of BSA obtained from SDASO-L, SDASO-M, and SDASO-S XL-MS experiments. C, circular 2-D SDASO XL-maps of BSA based on SDASO-L, -M and -S cross-links respectively. Helical secondary structures are designated by dark gray regions. D, 3-D SDASO XL-maps of BSA on its crystal structure (PDB: 4F5S) based on SDASO-L, -M, and -S cross-links, respectively. E, 3-D XL-map of BSA (PDB: 4F5S) generated based on the combined cross-links from DSSO (blue)+DHSO (red)+BMSO (purple) XL-MS experiments (10, 12). F, distance distribution plots of the identified SDASO cross-links to the BSA structure (PDB: 4F5S) (SDASO-L: ≤35 Å, SDASO-M and -S: ≤30 Å). Note: Colors schemes represent specific linkers: SDASO-L: light green, SDASO-M: light blue, and SDASO-S: gold orange. SDASO-L, Succinimidyl diazirine sulfoxide (long) aka. 2,5-Dioxopyrrolidin-1-yl 3-((2-(3-(3-methyl-3H-diazirin-3-yl)propanamido)ethyl)sulfinyl) propanoate; SDASO-M, succinimidyl diazirine sulfoxide (medium) aka. 2,5-Dioxopyrrolidin-1-yl 3-((3-(3-methyl-3H-diazirin-3-yl)propyl)sulfinyl)propanoate; SDASO-S, succinimidyl diazirine sulfoxide (short) aka. 2,5-Dioxopyrrolidin-1-yl 3-((2-(3-methyl-3H-diazirin-3-yl)ethyl)sulfinyl)propanoate; XL-MS: cross-linking mass spectrometry.