Abstract

The overall objective of this project is to investigate the active site of monoamine oxidase (MAO) and to unravel the molecular basis for the catalytic differences between the two types of MAO (MAO-A and B). This investigation will be conducted with the two photoaffinity labeling probes developed in this laboratory: 4-fluoro-3-nitrophenyl azide (FNPA) and 2 nitro-4-azidophenyl-dopamine (NAP-dopamine). FNPA has been shown to be a selective photoaffinity labeling probe for MAO-B, whereas NAP-dopamine was found to be able to inhibit both MAO-A and B photodependently. In addition, we have found that FNPA labels the active site of MAO-B as regions different from the FAD binding site, namely, the substrate binding site. In this application, the [H3]FNPA label d active site peptides produced by complete tryptic-chymotryptic digestion of the [H3]FNPA photolabeled beef liver MAO-B will be purified by reverse phase HPLC. The amino acid sequence of these labeled peptides will be determined by microsequencing techniques. This study will provide the first information on the substrate binding site of MAO-B. Furthermore, purified human placenta MAO-A and purified beef liver MAO-B will be labeled by [H3]NAP-dopamine. The biochemical nature of NAP-dopamine labeling site(s) on two MAO's will be characterized systematically by a series of protection experiments utilizing specific substrates and inhibitors of MAO. [H3]NAP-dopamine labeled active site peptides will be isolated by reverse phase HPLC and the amino acid sequences will be determined. This study will provide unequivocal evidence to demonstrate the structure differences that exist between MAO-A and -B. This investigation also has significant clinical application since MAO is an important enzyme in the metabolism of monoamine neurotransmitters. The level of MAO is altered in patients with certain mental disorders. Better understanding of the chemical nature of this enzyme and the molecular basis of the two types of MAO will help to better understand the mental diseases associated with this enzyme.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH039085-03
Application #
3377034
Study Section
(BPNA)
Project Start
1985-09-01
Project End
1988-08-31
Budget Start
1987-09-01
Budget End
1988-08-31
Support Year
3
Fiscal Year
1987
Total Cost
Indirect Cost

  Institution

Name
University of Southern California
Department
Type
Schools of Pharmacy
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90033

  Publications

Shih, Jean C (2018) Monoamine oxidase isoenzymes: genes, functions and targets for behavior and cancer therapy. J Neural Transm (Vienna) 125:1553-1566
Chen, Kevin; Kardys, Abbey; Chen, Yibu et al. (2017) Altered gene expression in early postnatal monoamine oxidase A knockout mice. Brain Res 1669:18-26
Kushal, Swati; Wang, Weijun; Vaikari, Vijaya Pooja et al. (2016) Monoamine oxidase A (MAO A) inhibitors decrease glioma progression. Oncotarget 7:13842-53
Godar, Sean C; Bortolato, Marco; Richards, Sarah E et al. (2015) Monoamine Oxidase A is Required for Rapid Dendritic Remodeling in Response to Stress. Int J Neuropsychopharmacol 18:
Kaludercic, Nina; Carpi, Andrea; Nagayama, Takahiro et al. (2014) Monoamine oxidase B prompts mitochondrial and cardiac dysfunction in pressure overloaded hearts. Antioxid Redox Signal 20:267-80
Godar, Sean C; Bortolato, Marco; Castelli, M Paola et al. (2014) The aggression and behavioral abnormalities associated with monoamine oxidase A deficiency are rescued by acute inhibition of serotonin reuptake. J Psychiatr Res 56:1-9
Singh, Chanpreet; Bortolato, Marco; Bali, Namrata et al. (2013) Cognitive abnormalities and hippocampal alterations in monoamine oxidase A and B knockout mice. Proc Natl Acad Sci U S A 110:12816-21
Bortolato, Marco; Godar, Sean C; Tambaro, Simone et al. (2013) Early postnatal inhibition of serotonin synthesis results in long-term reductions of perseverative behaviors, but not aggression, in MAO A-deficient mice. Neuropharmacology 75:223-32
Bortolato, Marco; Godar, Sean C; Alzghoul, Loai et al. (2013) Monoamine oxidase A and A/B knockout mice display autistic-like features. Int J Neuropsychopharmacol 16:869-88
Alzghoul, Loai; Bortolato, Marco; Delis, Foteini et al. (2012) Altered cerebellar organization and function in monoamine oxidase A hypomorphic mice. Neuropharmacology 63:1208-17

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