4GQQ | pdb_00004gqq

Human pancreatic alpha-amylase with bound ethyl caffeate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 
    0.227 (Depositor), 0.225 (DCC) 
  • R-Value Work: 
    0.197 (Depositor), 0.196 (DCC) 

wwPDB Validation 3D Report Full Report

Validation slider image for 4GQQ

Ligand Structure Quality Assessment 


This is version 2.1 of the entry. See complete history

Literature

Order and disorder: differential structural impacts of myricetin and ethyl caffeate on human amylase, an antidiabetic target.

Williams, L.K.Li, C.Withers, S.G.Brayer, G.D.

(2012) J Med Chem 55: 10177-10186

  • DOI: https://doi.org/10.1021/jm301273u
  • Primary Citation Related Structures: 
    4GQQ, 4GQR

  • PubMed Abstract: 

    The increasing prevalence of diabetes has accelerated the search for new drugs derived from natural sources. To define the functional features of two such families of compounds, the flavonols and the ethyl caffeates, we have determined the high-resolution structures of representative inhibitors in complex with human pancreatic α-amylase. Myricetin binds at the active site and interacts directly with the catalytic residues despite its bulky planar nature. Notably, it reduces the normal conformational flexibility of the adjacent substrate binding cleft. In contrast, bound ethyl caffeate acts by disordering precisely those polypeptide chain segments that make up the active site binding cleft. It also operates from binding sites far removed from the active site, a property not observed in any other class of human α-amylase inhibitor studied to date. Given the current inadequacy of drugs directed at diabetes, the use of optimized flavonols and ethyl caffeates may present an alternative therapeutic route.


  • Organizational Affiliation
    • Department of Biochemistry and Molecular Biology, University of British Columbia , Vancouver, British Columbia V6T 1Z3, Canada.

Macromolecule Content 

  • Total Structure Weight: 56.85 kDa 
  • Atom Count: 4,247 
  • Modeled Residue Count: 496 
  • Deposited Residue Count: 496 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Pancreatic alpha-amylase496Homo sapiensMutation(s): 0 
Gene Names: AMY2A
EC: 3.2.1.1
UniProt & NIH Common Fund Data Resources
Find proteins for P04746 (Homo sapiens)
Explore P04746 
Go to UniProtKB:  P04746
PHAROS:  P04746
GTEx:  ENSG00000243480 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04746
Glycosylation
Glycosylation Sites: 1Go to GlyGen: P04746-1
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NAG

Query on NAG



Download:Ideal Coordinates CCD File
B [auth A]2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
0XR

Query on 0XR



Download:Ideal Coordinates CCD File
C [auth A],
D [auth A],
E [auth A]
ethyl (2E)-3-(3,4-dihydroxyphenyl)prop-2-enoate
C11 H12 O4
WDKYDMULARNCIS-GQCTYLIASA-N
CA

Query on CA



Download:Ideal Coordinates CCD File
G [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
CL

Query on CL



Download:Ideal Coordinates CCD File
F [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
PCA
Query on PCA
A
L-PEPTIDE LINKINGC5 H7 N O3GLN

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free:  0.227 (Depositor), 0.225 (DCC) 
  • R-Value Work:  0.197 (Depositor), 0.196 (DCC) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.06α = 90
b = 68.12β = 90
c = 125.91γ = 90
Software Package:
Software NamePurpose
Web-Icedata collection
CNSrefinement
MOSFLMdata reduction
SCALAdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-10-24
    Type: Initial release
  • Version 1.1: 2012-12-12
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Polymer sequence, Refinement description, Structure summary
  • Version 2.1: 2024-11-27
    Changes: Data collection, Database references, Structure summary