The @entity14688 system, which consists of a family of proteins, including @entity14688 ( @entity14688 ), peroxiredoxin (Prx), and @entity19877 ( @entity19877 ), plays a critical role in the defense against oxidative stress by removing harmful @entity273 ( @entity274 ). Specifically, @entity14688 donates electrons to Prx to remove @entity274 and then @entity19877 maintains the reduced @entity14688 concentration with @entity1110 as the cofactor. Despite a great deal of kinetic information gathered on the removal of @entity274 by the @entity14688 system from various sources/species, a mechanistic understanding of the associated enzymes is still not available. We address this issue by developing a thermodynamically consistent mathematical model of the @entity14688 system which entails mechanistic details and provides quantitative insights into the kinetics of the @entity19877 and Prx enzymes. Consistent with experimental studies, the model analyses of the available data show that both enzymes operate by a ping-pong mechanism. The proposed mechanism for @entity19877 , which incorporates substrate inhibition by @entity1110 and intermediate protonation states, well describes the available data and accurately predicts the bell-shaped behavior of the effect of pH on the @entity19877 activity. Most importantly, the model also predicts the inhibitory effects of the reaction products ( @entity1110 and @entity14688 (SH)2) on the @entity19877 activity for which suitable experimental data are not available. The model analyses of the available data on the kinetics of Prx from @entity1 sources reveal that Prx operates at very low @entity274 concentrations compared to their @entity1 parasite counterparts. Furthermore, the model is able to predict the dynamic overoxidation of Prx at high @entity274 concentrations, consistent with the available data. The integrated Prx- @entity19877 model simulations well describe the @entity1110 and @entity274 degradation dynamics and also show that the coupling of @entity19877 - and Prx-dependent reduction of @entity274 allowed ultrasensitive changes in the @entity14688 concentration in response to changes in the @entity19877 concentration at high Prx concentrations. Thus, the model of this sort is very useful for integration into computational @entity274 degradation models to identify its role in physiological and pathophysiological functions.

Mechanistic characterization of the @entity14688 system in the removal of XXXX .

@entity1 :: ('9606', 'Species') :: ['mammalian', 'human'] @entity274 :: ('CHEBI:16240', 'Chemical') :: ['H2O2'] @entity1110 :: ('MESH:D009249', 'Chemical') :: ['NADP(+)', 'NADPH'] @entity273 :: ('MESH:D006861', 'Chemical') :: ['hydrogen peroxide'] @entity14688 :: ('7295', 'Gene') :: ['thioredoxin', 'Trx'] @entity19877 :: ('25824', 'Gene') :: ['thioredoxin reductase', 'TrxR']
@entity273 :: (MESH:D006861,Chemical) :: ['hydrogen peroxide']
