Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 63.60 kDa 
• Atom Count: 4635 
• Modelled Residue Count: 533 
• Deposited Residue Count: 543 
• Unique protein chains: 1

1U65

Ache W. CPT-11

• DOI: 10.2210/pdb1U65/pdb

• Classification: HYDROLASE
• Organism(s): Tetronarce californica
• Mutation(s): No 


• Deposited: 2004-07-29 Released: 2005-07-19 
• Deposition Author(s): Harel, M., Hyatt, J.L., Brumshtein, B., Morton, C.L., Wadkins, R.W., Silman, I., Sussman, J.L., Potter, P.M., Israel Structural Proteomics Center (ISPC)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.61 Å
• R-Value Free: 0.237 
• R-Value Work: 0.187 
• R-Value Observed: 0.187 

Literature

The crystal structure of the complex of the anticancer prodrug 7-ethyl-10-[4-(1-piperidino)-1-piperidino]-carbonyloxycamptothecin (CPT-11) with Torpedo californica acetylcholinesterase provides a molecular explanation for its cholinergic action

Harel, M., Hyatt, J.L., Brumshtein, B., Morton, C.L., Yoon, K.J., Wadkins, R.M., Silman, I., Sussman, J.L., Potter, P.M.

(2005) Mol Pharmacol 67: 1874-1881

• PubMed: 15772291 
• DOI: 10.1124/mol.104.009944
• Primary Citation of Related Structures:  
  1U65


• PubMed Abstract: 
  

The anticancer prodrug 7-ethyl-10-[4-(1-piperidino)-1-piperidino-]carbonyloxycamptothecin (CPT-11) is a highly effective camptothecin analog that has been approved for the treatment of colon cancer. It is hydrolyzed by carboxylesterases to yield 7-ethyl-10-hydroxycamptothecin (SN-38), a potent topoisomerase I poison. However, upon high-dose intravenous administration of CPT-11, a cholinergic syndrome is observed that can be ameliorated by atropine. Previous studies have indicated that CPT-11 can inhibit acetylcholinesterase (AChE), and here, we provide a detailed analysis of the inhibition of AChE by CPT-11 and by structural analogs. These studies demonstrate that the terminal dipiperidino moiety in CPT-11 plays a major role in enzyme inhibition, and this has been confirmed by X-ray crystallographic studies of a complex of the drug with Torpedo californica AChE. Our results indicate that CPT-11 binds within the active site gorge of the protein in a fashion similar to that observed with the Alzheimer drug donepezil. The 3D structure of the CPT-11/AChE complex also permits modeling of CPT-11 complexed with mammalian butyrylcholinesterase and carboxylesterase, both of which are known to hydrolyze the drug to the active metabolite. Overall, the results presented here clarify the mechanism of AChE inhibition by CPT-11 and detail the interaction of the drug with the protein. These studies may allow the design of both novel camptothecin analogs that would not inhibit AChE and new AChE inhibitors derived from the camptothecin scaffold.

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Organizational Affiliation: 

Department of Molecular Pharmacology, St. Jude Children's Research Hospital, 332 N. Lauderdale, Memphis, TN 38105, USA. [e-mail]

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Acetylcholinesterase	A	543	Tetronarce californica	Mutation(s): 0  Gene Names: ache EC: 3.1.1.7
UniProt
Find proteins for P04058 (Tetronarce californica) Explore P04058  Go to UniProtKB:  P04058

Oligosaccharides

Help

Entity ID: 2
Molecule	Chains	Chain Length	2D Diagram	Glycosylation
beta-L-fucopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose	B	2		N-Glycosylation
Glycosylation Resources
GlyTouCan:  G95595RA GlyCosmos:  G95595RA GlyGen:  G95595RA

Entity ID: 3
Molecule	Chains	Chain Length	2D Diagram	Glycosylation
alpha-L-fucopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose	C	2		N-Glycosylation
Glycosylation Resources
GlyTouCan:  G80587NA GlyCosmos:  G80587NA GlyGen:  G80587NA

Entity ID: 4
Molecule	Chains	Chain Length	2D Diagram	Glycosylation
alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose	D	2		N/A
Glycosylation Resources
GlyTouCan:  G35893LO GlyCosmos:  G35893LO GlyGen:  G35893LO

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CP0 (Subject of Investigation/LOI)	G [auth A]	(4S)-4,11-DIETHYL-4-HYDROXY-3,14-DIOXO-3,4,12,14-TETRAHYDRO-1H-PYRANO[3',4':6,7]INDOLIZINO[1,2-B]QUINOLIN-9-YL 1,4'-BIPIPERIDINE-1'-CARBOXYLATE C33 H38 N4 O6 UWKQSNNFCGGAFS-XIFFEERXSA-N
NAG (Subject of Investigation/LOI)	E [auth A], F [auth A]	2-acetamido-2-deoxy-beta-D-glucopyranose C8 H15 N O6 OVRNDRQMDRJTHS-FMDGEEDCSA-N
IOD	H [auth A]	IODIDE ION I XMBWDFGMSWQBCA-UHFFFAOYSA-M

Binding Affinity Annotations
ID	Source	Binding Affinity
CP0	PDBBind:  1U65	Ki: 26.4 (nM) from 1 assay(s)
	BindingDB:  1U65	Ki: 26 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.61 Å
• R-Value Free: 0.237 
• R-Value Work: 0.187 
• R-Value Observed: 0.187 
• Space Group: P 3₂ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 137.87	α = 90
b = 137.87	β = 90
c = 70.89	γ = 120

Software Package:

Software Name	Purpose
XDS	data scaling
XDS	data reduction
CNS	refinement
CNS	phasing

Structure Validation

Ligand Structure Quality Assessment  

Entry History 

Deposition Data

• Deposited Date: 2004-07-29 
• Released Date: 2005-07-19 
Deposition Author(s): Harel, M., Hyatt, J.L., Brumshtein, B., Morton, C.L., Wadkins, R.W., Silman, I., Sussman, J.L., Potter, P.M., Israel Structural Proteomics Center (ISPC)

Revision History  

• Version 1.0: 2005-07-19
  Type: Initial release
  
• Version 1.1: 2008-04-30
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Non-polymer description, Version format compliance
• Version 2.0: 2020-07-29
  Type: Remediation
  Reason: Carbohydrate remediation
  Changes: Advisory, Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary
• Version 3.0: 2021-06-02
  Changes: Advisory, Atomic model, Data collection, Derived calculations, Structure summary