HUMAN MONOAMINE OXIDASE B IN COMPLEX WITH N-(2-aminoethyl)-p-chlorobenzamide

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.194 

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This is version 1.2 of the entry. See complete history


Insights Into the Mode of Inhibition of Human Mitochondrial Monoamine Oxidase B from High-Resolution Crystal Structures

Binda, C.Li, M.Hubalek, F.Restelli, N.Edmondson, D.E.Mattevi, A.

(2003) Proc Natl Acad Sci U S A 100: 9750

  • DOI: https://doi.org/10.1073/pnas.1633804100
  • Primary Citation of Related Structures:  
    1OJ9, 1OJA, 1OJC, 1OJD

  • PubMed Abstract: 

    Monoamine oxidase B (MAO-B) is an outer mitochondrial membrane-bound enzyme that catalyzes the oxidative deamination of arylalkylamine neurotransmitters and has been a target for a number of clinically used drug inhibitors. The 1.7-A structure of the reversible isatin-MAO-B complex has been determined; it forms a basis for the interpretation of the enzyme's structure when bound to either reversible or irreversible inhibitors. 1,4-Diphenyl-2-butene is found to be a reversible MAO-B inhibitor, which occupies both the entrance and substrate cavity space in the enzyme. Comparison of these two structures identifies Ile-199 as a "gate" between the two cavities. Rotation of the side chain allows for either separation or fusion of the two cavities. Inhibition of the enzyme with N-(2-aminoethyl)-p-chlorobenzamide results in the formation of a covalent N(5) flavin adduct with the phenyl ring of the inhibitor occupying a position in the catalytic site overlapping that of isatin. Inhibition of MAO-B with the clinically used trans-2-phenylcyclopropylamine results in the formation of a covalent C(4a) flavin adduct with an opened cyclopropyl ring and the phenyl ring in a parallel orientation to the flavin. The peptide bond between the flavin-substituted Cys-397 and Tyr-398 is in a cis conformation, which allows the proper orientation of the phenolic ring of Tyr-398 in the active site. The flavin ring exists in a twisted nonplanar conformation, which is observed in the oxidized form as well as in both the N(5) and the C(4a) adducts. An immobile water molecule is H-bonded to Lys-296 and to the N(5) of the flavin as observed in other flavin-dependent amine oxidases. The active site cavities are highly apolar; however, hydrophilic areas exist near the flavin and direct the amine moiety of the substrate for binding and catalysis. Small conformational changes are observed on comparison of the different inhibitor-enzyme complexes. Future MAO-B drug design will need to consider "induced fit" contributions as an element in ligand-enzyme interactions.

  • Organizational Affiliation

    Department of Genetics and Microbiology, University of Pavia, Via Abbiategrasso, 27100 Pavia, Italy.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
520Homo sapiensMutation(s): 0 
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P27338 (Homo sapiens)
Explore P27338 
Go to UniProtKB:  P27338
PHAROS:  P27338
GTEx:  ENSG00000069535 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP27338
Sequence Annotations
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
LAZ BindingDB:  1OJC IC50: 685 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.194 
  • Space Group: C 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 131.69α = 90
b = 223.08β = 90
c = 86.47γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-08-15
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance