Redox Regulation of Protein Tyrosine Phosphatases

Parsons, Zachary D.; Gates, Kent S.

doi:10.1016/b978-0-12-405881-1.00008-2

Cited by 27 publications

(16 citation statements)

References 45 publications

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“…31 In the case of the DCS-inhibited enzyme, the Kitz and Wilson replot suggests the formation of a low affinity inhibitor–enzyme complex which intercepts at the origin. 29,32 This prevents an accurate estimation of K I and k inact values when using a linear regression method. 29,32 No activity is recovered from the inactivated enzyme after several hours of dialysis, arguing that the inactivation is irreversible (data not shown).…”

Section: Resultsmentioning

confidence: 99%

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Mechanism-Based Inhibition of the Mycobacterium tuberculosis Branched-Chain Aminotransferase by d- and l-Cycloserine

et al. 2017

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The branched-chain aminotransferase is a pyridoxal 5′-phosphate (PLP)-dependent enzyme responsible for the final step in the biosynthesis of all three branched-chain amino acids, L-leucine, L-isoleucine, and L-valine, in bacteria. We have investigated the mechanism of inactivation of the branched-chain aminotransferase from Mycobacterium tuberculosis (MtIlvE) by D- and L-cycloserine. D-Cycloserine is currently used only in the treatment of multidrug–drug-resistant tuberculosis. Our results show a time-and concentration-dependent inactivation of MtIlvE by both isomers, with L-cycloserine being a 40-fold better inhibitor of the enzyme. Minimum inhibitory concentration (MIC) studies revealed that L-cycloserine is a 10-fold better inhibitor of Mycobacterium tuberculosis growth than D-cycloserine. In addition, we have crystallized the MtIlvE-D-cycloserine inhibited enzyme, determining the structure to 1.7 Å. The structure of the covalent D-cycloserine-PMP adduct bound to MtIlvE reveals that the D-cycloserine ring is planar and aromatic, as previously observed for other enzyme systems. Mass spectrometry reveals that both the D-cycloserine- and L-cycloserine-PMP complexes have the same mass, and are likely to be the same aromatized, isoxazole product. However, the kinetics of formation of the MtIlvE D-cycloserine-PMP and MtIlvE L-cycloserine-PMP adducts are quite different. While the kinetics of the formation of the MtIlvE D-cycloserine-PMP complex can be fit to a single exponential, the formation of the MtIlvE L-cycloserine-PMP complex occurs in two steps. We propose a chemical mechanism for the inactivation of D- and L-cycloserine which suggests a stereochemically determined structural role for the differing kinetics of inactivation. These results demonstrate that the mechanism of action of D-cycloserine’s activity against M. tuberculosis may be more complicated than previously thought and that D-cycloserine may compromise the in vivo activity of multiple PLP-dependent enzymes, including MtIlvE.

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Section: Resultsmentioning

confidence: 99%

“…29,32 This prevents an accurate estimation of K I and k inact values when using a linear regression method. 29,32 No activity is recovered from the inactivated enzyme after several hours of dialysis, arguing that the inactivation is irreversible (data not shown). In comparison to DCS, LCS is a more efficient inhibitor of Mt IlvE.…”

Section: Resultsmentioning

confidence: 99%

Mechanism-Based Inhibition of the Mycobacterium tuberculosis Branched-Chain Aminotransferase by d- and l-Cycloserine

et al. 2017

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“…This concentration of propionaldehyde is sufficient to prevent any additional DEAB-dependent inactivation of both ALDH1A2 and ALDH2, thereby obviating the need for sample dilution prior to assay. The apparent bimolecular rate constants for inactivation were determined using traditional linear analysis of covalent enzyme inactivation [27]:

ln (\frac{{italicActivity}_{t}}{{italicACtivity}_{0}} \times) = - k' * t

…”

Section: Methodsmentioning

confidence: 99%

N,N-diethylaminobenzaldehyde (DEAB) as a substrate and mechanism-based inhibitor for human ALDH isoenzymes

Morgan

Parajuli

Buchman

et al. 2015

Chemico-Biological Interactions

108

112

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N,N-diethylaminobenzaldehyde (DEAB) is a commonly used “selective” inhibitor of aldehyde dehydrogenase isoenzymes in cancer stem cell biology due to its inclusion as a negative control compound in the widely utilized Aldefluor assay. Recent evidence has accumulated that DEAB is not a selective inhibitory agent when assayed in vitro versus ALDH1, ALDH2 and ALDH3 family members. We sought to determine the selectivity of DEAB toward ALDH1A1, ALDH1A2, ALDH1A3, ALDH1B1, ALDH1L1, ALDH2, ALDH3A1, ALDH4A1 and ALDH5A1 isoenzymes and determine the mechanism by which DEAB exerts its inhibitory action. We found that DEAB is an excellent substrate for ALDH3A1, exhibiting a Vmax/KM that exceeds that of its commonly used substrate, benzaldehyde. DEAB is also a substrate for ALDH1A1, albeit an exceptionally slow one (turnover rate ~0.03 min−1). In contrast, little if any turnover of DEAB was observed when incubated with ALDH1A2, ALDH1A3, ALDH1B1, ALDH2 or ALDH5A1. DEAB was neither a substrate nor an inhibitor for ALDH1L1 or ALDH4A1. Analysis by enzyme kinetics and QTOF mass spectrometry demonstrates that DEAB is an irreversible inhibitor of ALDH1A2 and ALDH2 with apparent bimolecular rate constants of 2900 and 86,000 M−1 s−1, respectively. The mechanism of inactivation is consistent with the formation of quinoid-like resonance state following hydride transfer that is stabilized by local structural features that exist in several of the ALDH isoenzymes.

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“…[11] The codetection of phosphatase activity and [RONS] has potential ramifications for drug discovery. PTPs and RONS [15] ) are currently lacking. [3] Crucially, methods (luminescent or other) for the real-time measurement of enzymes and their regulators (e.g.…”

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confidence: 99%

Multiplex Detection of Enzymatic Activity with Responsive Lanthanide‐Based Luminescent Probes

Pershagen

Borbas

2014

Angew Chem Int Ed

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Multiplex analyte detection in complex dynamic systems is desirable for the investigation of cellular communication networks as well as in medical diagnostics. A family of lanthanide-based responsive luminescent probes for multiplex detection is reported. The high modularity of the probe design enabled the rapid assembly of both green and red emitters for a large variety of analytes by the simple exchange of the lanthanide or an analyte-cleavable caging group, respectively. The real-time three-color detection of up to three analytes was demonstrated, thus setting the stage for the non-invasive investigation of interconnected biological processes.

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Redox Regulation of Protein Tyrosine Phosphatases

Cited by 27 publications

References 45 publications

Mechanism-Based Inhibition of the Mycobacterium tuberculosis Branched-Chain Aminotransferase by d- and l-Cycloserine

Mechanism-Based Inhibition of the Mycobacterium tuberculosis Branched-Chain Aminotransferase by d- and l-Cycloserine

N,N-diethylaminobenzaldehyde (DEAB) as a substrate and mechanism-based inhibitor for human ALDH isoenzymes

Multiplex Detection of Enzymatic Activity with Responsive Lanthanide‐Based Luminescent Probes

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