Direct Continuous Fluorometric Assay for Monoamine Oxidase B

Zhou, Jianxing; Zhong, Buqing; Silverman, Richard B.

doi:10.1006/abio.1996.0041

Cited by 28 publications

(17 citation statements)

References 4 publications

(6 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…MAO A and B are enzymes with wide specificity for their role in endogenous and xenobiotic metabolism. They oxidize many amines (primary, secondary or some tertiary), providing a multitude of ways to assay the activity [ 135 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , 174 ]. The reactions that can be used to link MAO catalytic activity to conveniently measurable products are shown in Figure 11 .…”

Section: Mao Assaysmentioning

confidence: 99%

Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs

2017

View full text Add to dashboard Cite

The actions of many drugs involve enzyme inhibition. This is exemplified by the inhibitors of monoamine oxidases (MAO) and the cholinsterases (ChE) that have been used for several pharmacological purposes. This review describes key principles and approaches for the reliable determination of enzyme activities and inhibition as well as some of the methods that are in current use for such studies with these two enzymes. Their applicability and potential pitfalls arising from their inappropriate use are discussed. Since inhibitor potency is frequently assessed in terms of the quantity necessary to give 50% inhibition (the IC50 value), the relationships between this and the mode of inhibition is also considered, in terms of the misleading information that it may provide. Incorporation of more than one functionality into the same molecule to give a multi-target-directed ligands (MTDLs) requires careful assessment to ensure that the specific target effects are not significantly altered and that the kinetic behavior remains as favourable with the MTDL as it does with the individual components. Such factors will be considered in terms of recently developed MTDLs that combine MAO and ChE inhibitory functions.

show abstract

Section: Mao Assaysmentioning

confidence: 99%

Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs

2017

View full text Add to dashboard Cite

show abstract

“…Based on the general reaction RCH 2 NR 1 R 2 + H 2 O+O 2 -→ RCHO + NHR 1 R 2 + H 2 O 2 , available assays to measure MAO activity can be summarized either by determining the rate of product formation or substrates depleted in an MAOcatalyzed reaction: (1) the direct measurement of oxygen consumption by polarographic detection [6] ; (2) the detection of oxidized monoamine products by spectrophotometry or radiometric assay [7,8] ited convenience [9] ; (4) the assessment of co-product hydrogen peroxide directly [10] or indirectly, a continuous fluorescence assay with a sensitive, stable H 2 O 2 probe, N-acetyl-3,7-dihydroxyphenoxazine (Amplex Red). Because of its convenience and continuity, this one-step method was considered more suitable to detect the activity of enzymes whose co-product is hydrogen peroxide.…”

Section: Introductionmentioning

confidence: 99%

High-throughput screening for monoamine oxidase-A and monoamine oxidase-B inhibitors using one-step fluorescence assay1

Guang

2006

Acta Pharmacologica Sinica

View full text Add to dashboard Cite

Aim: To develop high‐throughput screening (HTS) assays for monoamine oxidase (MAO)‐A and MAO‐B inhibitors. Methods: A fluorescence probe based method measuring MAO‐A and MAO‐B activity was established and optimized, with its sensitivity, stability and specificity evaluated. Reaction conditions including enzyme sources, substrate concentrations, incubation volume and reaction time in 384‐well format were optimized to achieve sensitive and low consumptive goal. Results: In optimized conditions, dynamic parameters of MAO‐A and MAO‐B were obtained. The Km value of serotonin to MAO‐A was 1.66 μmol/L, while that of benzylamine to MAO‐B was 0.80 μmol/L. The IC50 value of clorgyline to MAO‐A was 2.99 nmol/L, and that of deprenyl to MAO‐B was 7.04 nmol/L, matching those obtained from traditional spectrometric assays. Among tested samples, one compound exerted an inhibitory effect on MAO‐A activity with IC50 as 0.36 umol/L, and three compounds had an inhibitory effect on MAO‐B activity with IC50 as 0.13, 0.19, and 0.13 μmol/L. The Z′ factor was 0.71±0.03 and 0.75±0.03 in MAO‐A‐inhibitor and MAO‐B‐inhibitor HTS system, respectively. Conclusion: The established assays can be well applied to MAO‐A and MAO‐B inhibitor screening with high quality, precision and reproducibility.

show abstract

“…Of the various types of standard assays employed to detect MAO activities [14][15][16][17][18][19][20][21][22] , advanced fluorescence-based methods might be suitable in this context 23 , owing to their practicality, high sensitivity and amenability to deep-tissue bioimaging (that is, by using nearinfrared 24 or two-photon techniques 25 ); however, few provide any MAO-A/B selectivity 22 . For example, the commercially available Amplex Red kit and ELISA kit (ab109912), as well as several other existing fluorimetric approaches [14][15][16] , measures the fluorescent product liberated from the oxidation of the corresponding amine substrate by MAOs, in many cases with the assistance of a secondary enzyme or activating reagent (for example, NaIO 4 ). Chang and co-workers 19 reported a small molecule resorufin-based probe capable of live-cell imaging of MAO activities.…”

mentioning

confidence: 99%

A sensitive two-photon probe to selectively detect monoamine oxidase B activity in Parkinson’s disease models

et al. 2014

View full text Add to dashboard Cite

The unusually high MAO-B activity consistently observed in Parkinson's disease (PD) patients has been proposed as a biomarker; however, this has not been realized due to the lack of probes suitable for MAO-B-specific detection in live cells/tissues. Here we report the first two-photon, small molecule fluorogenic probe (U1) that enables highly sensitive/specific and real-time imaging of endogenous MAO-B activities across biological samples. We also used U1 to confirm the reported inverse relationship between parkin and MAO-B in PD models. With no apparent toxicity, U1 may be used to monitor MAO-B activities in small animals during disease development. In clinical samples, we find elevated MAO-B activities only in B lymphocytes (not in fibroblasts), hinting that MAO-B activity in peripheral blood cells might be an accessible biomarker for rapid detection of PD. Our results provide important starting points for using small molecule imaging techniques to explore MAO-B at the organism level.

show abstract

Direct Continuous Fluorometric Assay for Monoamine Oxidase B

Cited by 28 publications

References 4 publications

Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs

Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs

High-throughput screening for monoamine oxidase-A and monoamine oxidase-B inhibitors using one-step fluorescence assay1

A sensitive two-photon probe to selectively detect monoamine oxidase B activity in Parkinson’s disease models

Contact Info

Product

Resources

About