TABLE 1

Binding constants of PQ912 for glutaminyl cyclases determined by enzyme kinetics (Ki, see Fig. 1 for an example) or by SPR (KD)

SpeciesPQ912 Ki Determined KineticallyaPQ912 Kinetic Constants Determined by SPR at pH 7.6
pH 6.0pH 8.0KDkonkoff
nMnMnMM-1s−1s−1
Human QC19 ± 3b25 ± 3171.3e62.3e−2
Mouse QC41 ± 362 ± 7ndndnd
  • nd, not determined; SPR, surface plasmone resonance.

  • a For enzyme kinetic measurements of QC, two different batches of PQ912 free base were analyzed. For each batch and each pH value, three separate weighings were performed and analyzed as described in Materials and Methods; Ki determination with SPR for human QC were done once.

  • b Mean ± standard deviation.