2ZDK

Exploring Trypsin S3 Pocket


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.67 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.134 
  • R-Value Observed: 0.134 

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Ligand Structure Quality Assessment 


This is version 1.4 of the entry. See complete history


Literature

Congeneric but still distinct: how closely related trypsin ligands exhibit different thermodynamic and structural properties

Brandt, T.Holzmann, N.Muley, L.Khayat, M.Wegscheid-Gerlach, C.Baum, B.Heine, A.Hangauer, D.Klebe, G.

(2011) J Mol Biol 405: 1170-1187

  • DOI: https://doi.org/10.1016/j.jmb.2010.11.038
  • Primary Citation of Related Structures:  
    2ZDK, 2ZDL, 2ZDM, 2ZDN, 2ZFS, 2ZFT, 2ZHD, 2ZQ1, 2ZQ2, 3LJJ, 3LJO

  • PubMed Abstract: 

    A congeneric series of benzamidine-type ligands with a central proline moiety and a terminal cycloalkyl group--linked by a secondary amine, ether, or methylene bridge--was synthesized as trypsin inhibitors. This series of inhibitors was investigated by isothermal titration calorimetry, crystal structure analysis in two crystal forms, and molecular dynamics simulations. Even though all of these congeneric ligands exhibited essentially the same affinity for trypsin, their binding profiles at the structural, dynamic, and thermodynamic levels are very distinct. The ligands display a pronounced enthalpy/entropy compensation that results in a nearly unchanged free energy of binding, even though individual enthalpy and entropy terms change significantly across the series. Crystal structures revealed that the secondary amine-linked analogs scatter over two distinct conformational families of binding modes that occupy either the inside or of the outside the protein's S3/S4 specificity pocket. In contrast, the ether-linked and methylene-linked ligands preferentially occupy the hydrophobic specificity pocket. This also explains why the latter ligands could only be crystallized in the conformationally restricting closed crystal form whereas the derivative with the highest residual mobility in the series escaped our attempts to crystallize it in the closed form; instead, a well-resolved structure could only be achieved in the open form with the ligand in disordered orientation. These distinct binding modes are supported by molecular dynamics simulations and correlate with the shifting enthalpic/entropic signatures of ligand binding. The examples demonstrate that, at the molecular level, binding modes and thermodynamic binding signatures can be very different even for closely related ligands. However, deviating binding profiles provide the opportunity to optimally address a given target.


  • Organizational Affiliation

    Department of Pharmaceutical Chemistry, Philipps University Marburg, Marbacher Weg 6, 35032 Marburg, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cationic trypsin223Bos taurusMutation(s): 0 
EC: 3.4.21.4
UniProt
Find proteins for P00760 (Bos taurus)
Explore P00760 
Go to UniProtKB:  P00760
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00760
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
50U
Query on 50U

Download Ideal Coordinates CCD File 
D [auth A](S)-N-(4-carbamimidoylbenzyl)-1-(3-cyclohexylpropanoyl)pyrrolidine-2-carboxamide
C22 H32 N4 O2
DOTBZTLJSXFKCP-IBGZPJMESA-N
SO4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
GOL
Query on GOL

Download Ideal Coordinates CCD File 
F [auth A]
G [auth A]
H [auth A]
I [auth A]
J [auth A]
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
L [auth A]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
DMS
Query on DMS

Download Ideal Coordinates CCD File 
E [auth A]DIMETHYL SULFOXIDE
C2 H6 O S
IAZDPXIOMUYVGZ-UHFFFAOYSA-N
CA
Query on CA

Download Ideal Coordinates CCD File 
B [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
50U PDBBind:  2ZDK Kd: 428 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.67 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.134 
  • R-Value Observed: 0.134 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.6α = 90
b = 54.6β = 90
c = 108.6γ = 120
Software Package:
Software NamePurpose
SHELXmodel building
SHELXL-97refinement
CrystalCleardata collection
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-10-14
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.2: 2012-12-12
    Changes: Other
  • Version 1.3: 2014-01-22
    Changes: Database references
  • Version 1.4: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description