Ultraflex extreme maldi tof tof ms

The binding stoichiometry of 6PGDH, RpoA, and Pgl to silver were measured by MALDI-TOF MS (Bruker ultraflex extreme MALDI-TOF-TOF-MS). Proteins after incubation with different molar equivalents of Ag⁺ at room temperature for 1 h were mixed with saturated sinapic acid matrix (in ACN:H₂O = 1:1). Prior to MALDI-TOF MS analysis, 1 μL proteins (10 μM) was mixed with 1 μL matrix and crystalized on polished 384-well plate. Mass spectra were measured in the positive linear mode.

The binding of AUR to NDM-1 was examined by matrix assisted laser ionization time of flight mass spectrometry (MALDI-TOF MS) (Bruker ultraflex extreme MALDI-TOF-TOF-MS). NDM-1 protein was incubated with 10 molar equivalents of AUR at 4 °C for 12 h. One microliter of the protein sample was mounted on a modified stainless-steel sample plate using electrically conductive tapes (9713 XYZ-Axis; 3 M, St. Paul, MN) and then overlaid with 1 μL of matrix solution (saturated sinapic acid in ACN: H₂O = 50: 50). The plate was then introduced into the mass spectrometer, operating in the positive reflectron mode. The mass resolution of ion peaks was recorded in the range of m/z 20,000–40,000. MS data were processed using FlexAnalysis (version 1.2, Bruker Daltonics).