6OIA

(1S,3S)-3-amino-4-(perfluoropropan-2-ylidene)cyclopentane-1-carboxylic acid hydrochloride, a potent inhibitor of ornithine aminotransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.163 

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This is version 1.2 of the entry. See complete history


Literature

Mechanism of Inactivation of Ornithine Aminotransferase by (1S,3S)-3-Amino-4-(hexafluoropropan-2-ylidenyl)cyclopentane-1-carboxylic Acid.

Moschitto, M.J.Doubleday, P.F.Catlin, D.S.Kelleher, N.L.Liu, D.Silverman, R.B.

(2019) J Am Chem Soc 141: 10711-10721

  • DOI: 10.1021/jacs.9b03254
  • Primary Citation of Related Structures:  
    6OIA

  • PubMed Abstract: 
  • The inhibition of ornithine aminotransferase (OAT), a pyridoxal 5'-phosphate-dependent enzyme, has been implicated as a treatment for hepatocellular carcinoma (HCC), the most common form of liver cancer, for which there is no effective treatment. From a previous evaluation of our aminotransferase inhibitors, (1 S ,3 S )-3-amino-4-(perfluoropropan-2-ylidene)cyclopentane-1-carboxylic acid hydrochloride ( 1 ) was found to be a selective and potent inactivator of human OAT ( h OAT), which inhibited the growth of HCC in athymic mice implanted with human-derived HCC, even at a dose of 0 ...

    The inhibition of ornithine aminotransferase (OAT), a pyridoxal 5'-phosphate-dependent enzyme, has been implicated as a treatment for hepatocellular carcinoma (HCC), the most common form of liver cancer, for which there is no effective treatment. From a previous evaluation of our aminotransferase inhibitors, (1 S ,3 S )-3-amino-4-(perfluoropropan-2-ylidene)cyclopentane-1-carboxylic acid hydrochloride ( 1 ) was found to be a selective and potent inactivator of human OAT ( h OAT), which inhibited the growth of HCC in athymic mice implanted with human-derived HCC, even at a dose of 0.1 mg/kg. Currently, investigational new drug (IND)-enabling studies with 1 are underway. The inactivation mechanism of 1 , however, has proved to be elusive. Here we propose three possible mechanisms, based on mechanisms of known aminotransferase inactivators: Michael addition, enamine addition, and fluoride ion elimination followed by conjugate addition. On the basis of crystallography and intact protein mass spectrometry, it was determined that 1 inactivates h OAT through fluoride ion elimination to an activated 1,1'-difluoroolefin, followed by conjugate addition and hydrolysis. This result was confirmed with additional studies, including the detection of the cofactor structure by mass spectrometry and through the identification of turnover metabolites. On the basis of this inactivation mechanism and to provide further evidence for the mechanism, analogues of 1 ( 19 , 20 ) were designed, synthesized, and demonstrated to have the predicted selective inactivation mechanism. These analogues highlight the importance of the trifluoromethyl group and provide a basis for future inactivator design.


    Organizational Affiliation

    Department of Chemistry and Biochemistry , Loyola University Chicago , Chicago , Illinois 60660 , United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Ornithine aminotransferase, mitochondrialA, B, C404Homo sapiensMutation(s): 0 
Gene Names: OAT
EC: 2.6.1.13
UniProt & NIH Common Fund Data Resources
Find proteins for P04181 (Homo sapiens)
Explore P04181 
Go to UniProtKB:  P04181
PHAROS:  P04181
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLP (Subject of Investigation/LOI)
Query on PLP

Download Ideal Coordinates CCD File 
D [auth A], F [auth B], I [auth C]PYRIDOXAL-5'-PHOSPHATE
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
MQ4 (Subject of Investigation/LOI)
Query on MQ4

Download Ideal Coordinates CCD File 
H [auth B], J [auth C](1S)-3-amino-4-[(2S)-1,1,1-trifluoro-3-oxopropan-2-yl]cyclopent-3-ene-1-carboxylic acid
C9 H10 F3 N O3
FRXHJQNUUVTCON-UJURSFKZSA-N
 Ligand Interaction
GOL
Query on GOL

Download Ideal Coordinates CCD File 
E [auth A], G [auth B]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.163 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 115.824α = 90
b = 115.824β = 90
c = 187.644γ = 120
Software Package:
Software NamePurpose
SCALAdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-3000data reduction
HKL-3000phasing

Structure Validation

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Ligand Structure Quality Assessment  



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2019-09-18
    Type: Initial release
  • Version 1.1: 2019-12-18
    Changes: Author supporting evidence
  • Version 1.2: 2020-04-01
    Changes: Database references