1YL9

3D Solution Structure of [Tyr3]Octreotate derivatives in DMSO


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 400 
  • Conformers Submitted: 21 
  • Selection Criteria: target function 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

3D solution structure of [Tyr3]octreotate derivatives in DMSO: structure differentiation of peptide core due to chelate group attachment and biologically active conformation.

Spyroulias, G.A.Galanis, A.S.Petrou, C.h.Vahliotis, D.Sotiriou, P.Nikolopoulou, A.Nock, B.Maina, T.Cordopatis, P.

(2005) Med Chem 1: 487-499

  • DOI: https://doi.org/10.2174/1573406054864089
  • Primary Citation of Related Structures:  
    1YL8, 1YL9

  • PubMed Abstract: 

    The solution models of [Tyr3]octreotate (DPhe1-Cys2-Tyr3-DTrp4-Lys5-Thr6-Cys7-Thr8-COOH, disulfide bridged) (I), its analogs functionalized with an open chain tetraamine chelator, N4-[Tyr3]octreotate (II), and the N4-(Asp)2-[Tyr3]octreotate (III) peptide have been determined through 2D 1H NMR spectroscopy in DMSO. Chemical shift analysis has been performed in an attempt to elucidate structural changes occurring during attachment of the tetraamine to the peptide backbone. NMR-derived geometrical constraints have been used in order to calculate high resolution conformers of the above peptides. Conformational analysis of the three synthetic analogues, have shown that these somatostatin analoges adopt a predominant antiparallel beta-sheet conformation characterized by a beta-like turn spanning residues DTrp4 and Lys5 which is supported in the case of N4-(Asp)2-[Tyr3]octreotate and N4-[Tyr3]octreotate by medium range NOEs. These data indicate that the above-mentioned molecules adopt a rather constrained structure in the 4-residue loop Tyr3-Thr6. Additionally, the C-terminal of [Tyr3]octreotate, comprising Cys7 and Thr8, appears to form a turn-like structure manifested by characteristic side-chain NOEs between Lys5 and Thr8, which have not been detected for the other two compounds. These data are discussed in the light of previous structural data of Sandostatin (octreotide) and suggest that attachment of the N4-chelator and two Asp residues at the N-end of [Tyr3]octreotate impose considerable structural changes and affect the binding properties of these peptides. Indeed, the IC50 values determined during competition binding assays against the sst2 (somatostatin subtype 2 receptor) suggest that the presence of the N4 group enhances receptor affinity, while extension of peptide chain by two negatively-charged Asp residues impairs receptor affinity at approximately one order of magnitude.


  • Organizational Affiliation

    Department of Pharmacy, School of Health Sciences, University of Patras, Panepistimioupoli - Rion, GR-26504 Patras, Greece. G.A.Spyroulias@upatras.gr


Macromolecules

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
[Tyr3]Octreotate8N/AMutation(s): 0 
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CH4
Query on CH4

Download Ideal Coordinates CCD File 
B [auth A]3-[(2-AMINOETHYL)AMINO]-2-{[(2-AMINOETHYL)AMINO]METHYL}PROPANAL
C8 H20 N4 O
BIJUMIIQWOKWMO-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 400 
  • Conformers Submitted: 21 
  • Selection Criteria: target function 

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-09-20
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-03-02
    Changes: Data collection, Database references, Derived calculations