Bovgdh

Glutamate dehydrogenase, purified from bovine liver (bovGDH), and Glutamate dehydrogenase, purified from Proteus spp. (bacGDH) were purchased from Sigma (St. Louis, MO, USA). Serum amyloid P component, purified from human serum (SAP), and recombinant human C-reactive protein, purified from Escherichia coli (CRP) were purchased from Calbiochem (San Diego, CA, USA). Standards used to construct collision cross-section (CCS) calibration curves, including cytochrome c (equine heart), avidin (egg white), concanavalin A (jack bean), alcohol dehydrogenase (Saccharomyces cerevisiae) and Glutamate dehydrogenase (bovine liver), as well as small molecules used to perform SAP-ligand binding experiment, including calcium acetate and deoxyadenosine monophosphate (dAMP) were all purchased from Sigma (St. Louis, MO, USA). Protein samples were buffer exchanged into 100 mM ammonium acetate at pH 7 (bovGDH, bacGDH and CCS calibrants) and pH 8 (SAP and CRP) using Micro Bio-Spin 6 columns (Bio-Rad, Hercules, CA) and prepared to a final concentration of 5 μM to 80 μM for bovGDH and 5 μM to 30 μM for SAP to perform concentration dependent analysis, and 5 μM for CCS calibrants.