Myeloperoxidase-catalyzed taurine chlorination: Initial versus equilibrium rate

Ramos, Daniel R.; García, M. V.; Canle, Moisés; Santaballa, J. Arturo; Furtmüller, Paul G.; Obinger, Christian

doi:10.1016/j.abb.2007.07.024

Cited by 30 publications

(44 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The obtained kinetic data on Tau chlorination [15] demonstrated the importance of Reaction (7) in deceleration of (N-Cl)-Tau formation at equilibrium phase, and ruled out a proton participating in the direct reaction between MPO-I and Cl À . Those findings support the formation of a chlorinating MPO-I-Cl complex and/or of ClO À stabilized in the inner protein core of MPO [24].…”

Section: Introductionmentioning

confidence: 78%

“…Very important is the role of H 2 O 2 as one-electron donor reducing MPO-I to MPO-II, which forms a complex with hydroperoxyl radical ðHO Á 2 Þ, MPO-II-HO 2 (Reaction (7)). Formation of this species has been proposed for explaining the experimentally obtained Tau-chlorination kinetic data, and is supported by the fact that free released HO Å 2 has not been observed under the working conditions [15]. MPO-II (or MPO-II-HO 2 ) is outside the halogenation cycle.…”

Section: Introductionmentioning

confidence: 91%

“…Plausibility of the mechanism previously validated for the MPO-catalyzed chlorination of Tau [15] was again tested in a pH range (pH 4.0-6.0) that comprises the actual conditions during phagocytosis and MPO activity in vivo.…”

Section: Reactionmentioning

confidence: 99%

“…Recently, we have extended the study of Marquez and Dunford [12] by following initial and equilibrium rate of formation of (N-Cl)-Tau by MPO at pH 4.0-7.0 in order to investigate the viability of several possible chlorination mechanisms [15]. In our model we considered also known side-reactions of system MPO/H 2 O 2 /Cl À /Tau (Table 1).…”

Section: Introductionmentioning

confidence: 98%

“…Thus, following the kinetic analysis of MPO-catalyzed chlorination of Tau [15] the study has been extended to another substrate, the tripeptide L-prolylglycylglycine (Pro-Gly-Gly). While Tau is a relatively small substrate (M r = 125.15, 14 atoms), Pro-Gly-Gly is bulkier (M r = 229.2, 31 atoms), therefore, a decrease in the reaction rate due to the steric hindrance of the tripeptide should be expected if chlorination involves the MPO-I-Cl complex.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Myeloperoxidase-catalyzed chlorination: The quest for the active species

Ramos

García

Canle

et al. 2008

Journal of Inorganic Biochemistry

Self Cite

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 91%

Section: Reactionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Myeloperoxidase-catalyzed chlorination: The quest for the active species

Ramos

García

Canle

et al. 2008

Journal of Inorganic Biochemistry

Self Cite

View full text Add to dashboard Cite

Oxidative Stress

Fridovich

2009

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Respiring organisms derive multiple benefits from molecular oxygen. However, some fraction of the oxygen used is unavoidably converted to dangerous substances such as the superoxide radical (O 2 − ), hydrogen peroxide (H 2 O 2 ) and the hydroxyl radical (HO). These intermediates of oxygen reduction threaten the integrity of diverse biological molecules and hence the life of cells and organisms. The seeming comfort of aerobes in the presence of oxygen is due to their content of multilayered defences against these reactive metabolites of oxygen. There are superoxide dismutases that eliminate O 2 − by efficiently converting it to oxygen and H 2 O 2 . There are catalases that eliminate H 2 O 2 by dismuting it into water plus oxygen and there are also peroxidases that eliminate H 2 O 2 and organic peroxides by reducing them to H 2 O 2 and to alcohols, respectively. Removing O 2 − and H 2 O 2 prevents the formation of HO. However, no defence is perfect so backing up these frontline defences, that in large measure prevent oxidative damage, are others that repair the damage caused by the reactive derivatives of oxygen and, when that is not possible, eliminate the damaged molecules and replace them with newly synthesized ones. Key concepts: The spin restriction facing oxygen reduction that favours the univalent pathway of oxygen reduction. Superoxide, hydrogen peroxide and hydroxyl radicalare intermediates on the univalent pathway. These intermediates are reactive and can cause damage. Defences are essential and have been evolved. Superoxide dismutases protect against superoxide by converting it to hydrogen peroxide plus oxygen. There are superoxide dismutases that contain copper plus zinc, manganese, iron or nickel at their active sites. Catalases protect against hydrogen peroxide by converting it to oxygen plus water. There catalases with haem iron at the active site and others with manganese. Peroxidases protect against hydrogen peroxide and against organic peroxides by reducing them to water and to alcohols, respectively. Removing both superoxide and hydrogen peroxide prevents the formation of hydroxyl radical. Oxidative stress contributes to multiple pathologies and to normal aging.

show abstract

Oxidative Stress

Fridovich

2014

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Respiring organisms derive multiple benefits from molecular oxygen. However, some fraction of the oxygen used is unavoidably converted into dangerously reactive substances such as the superoxide radical (O 2 − ), hydrogen peroxide (H 2 O 2 ) and the hydroxyl radical (HO). These intermediates of oxygen reduction to water threaten the integrity of diverse biological molecules and hence the life of cells and organisms. The seeming comfort of aerobes in the presence of oxygen is due to their content of multilayered defences against these reactive metabolites of oxygen. There are superoxide dismutases that eliminate O 2 − by efficiently dismuting it to oxygen and H 2 O 2 . There are catalases that eliminate H 2 O 2 by dismuting it into water plus oxygen and there are also peroxidases that eliminate H 2 O 2 and organic peroxides by reducing them to H 2 O and to alcohols, respectively. Removing O 2 − and H 2 O 2 prevents the formation of HO. However, no defence is perfect, so backing up these frontline defences that in large measure prevent oxidative damage, are others that repair the damage caused by the reactive derivatives of oxygen and, when that is not possible, eliminate the damaged molecules and replace them with newly synthesised ones. Key Concepts: The spin restriction facing oxygen reduction that favours the univalent pathway of oxygen reduction. Superoxide, hydrogen peroxide and hydroxyl radical are intermediates on the univalent pathway. These intermediates are reactive and can cause damage. Defences are essential and have been evolved. Superoxide dismutases protect against superoxide by converting it into hydrogen peroxide plus oxygen. There are superoxide dismutases that contain copper plus zinc, manganese, iron or nickel at their active sites. Catalases protect against hydrogen peroxide by converting it into oxygen plus water. There are catalases with haem iron at the active site and others with manganese. Peroxidases protect against hydrogen peroxide and against organic peroxides by reducing them to water and to alcohols, respectively. Removing both superoxide and hydrogen peroxide prevents the formation of hydroxyl radical. Oxidative stress contributes to multiple pathologies and to normal aging.

show abstract

Myeloperoxidase-catalyzed taurine chlorination: Initial versus equilibrium rate

Cited by 30 publications

References 32 publications

Myeloperoxidase-catalyzed chlorination: The quest for the active species

Myeloperoxidase-catalyzed chlorination: The quest for the active species

Oxidative Stress

Oxidative Stress

Contact Info

Product

Resources

About