Structural analysis of the interleukin-8/glycosaminoglycan interactions by amide hydrogen/deuterium exchange mass spectrometry

The effect of interleukin‐8 truncations on its interactions with glycosaminoglycans

“…Several distinct IL‐8 truncations have been characterized by analytical Hep affinity chromatography before and are in agreement with our data. These findings indicate that the C‐terminal helix is indispensable for Hep binding and support several studies that suggest a GAG binding mode along or across the helix axis, respectively …”

“…The C‐terminal α‐helix is known to be important for binding to GAGs resulting in a chemotactic gradient for neutrophil granulocytes during infection or inflammation . Particularly, the helix‐residing residues K59, V66, V67, K69, A74, and E75 play a major role in the interaction of IL‐8 with sulfated GAGs as shown in previous studies …”

“…Previous studies for IL‐8 identified the N‐terminus, containing the ELR motif, responsible for IL‐8 receptor binding and activation, while the C‐terminal part of IL‐8 is crucial for GAG binding . In order to characterize the molecular interactions in IL‐8/GAG systems further, we studied binding of IL‐8 to Hep as well as HA and its chemically sulfated derivatives.…”

The selected matrix influences the matrix‐assisted laser desorption/ionization time‐of‐flight mass spectral patterns of partially deuterated glycosaminoglycan disaccharides

“…Although the detailed reason for these differences remain unclear, this effect is likely at least partially caused by the transferred energy and thus the heating of the sample: a higher temperature of the evaporating matrix/analyte cocrystals results in a more significant H/D exchange. This trend correlates to the situation in solution where the H/D exchange can be slowed down considerably when the temperature is reduced …”

Use of deuterium labeling by high‐temperature solid‐state hydrogen‐exchange reaction for mass spectrometric analysis of bradykinin biotransformation

“…This approach is potentially applicable for kinetic studies, structural analysis as well as analysis of protein‐protein interactions and supramolecular complex formation. In contrast to deuterium labeling of selected moieties of various substances, the deuteration allows analysis of the metabolic transformation of all fragments of peptides or organic compounds of interest …”