The Vitros lactate method is also based on a lactate oxidase/peroxidase coupled reaction
. However, reaction conditions are obviously sufficiently different to avoid glycolic acid interference.
It is noted that with divalent [Cu.sup.2+] AQ does not show the coupled reaction
because [Cu.sup.2+] ions are already reduced to [Cu.sup.0] at a more positive potential before interacting with AQ, as shown in Figure 3.
To consider the influence of the proteolytic peptidylprolyl fragment, which is produced in large amounts in the fast phase of the coupled reaction
, we investigated the influence of succinyl-Ala-Ala-Pro-Phe-OH on the PPIase activity of a mixture of 10 sera and in a separate experiment with purified Cyp18 and FKBP12.