1MVZ

NMR solution structure of a Bowman Birk inhibitor isolated from snail medic seeds (Medicago Scutellata)


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 20 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Anticarcinogenic Bowman Birk inhibitor isolated from snail medic seeds (Medicago Scutellata): solution structure and analysis of self-association behaviour

Catalano, M.Ragona, L.Molinari, H.Tava, A.Zetta, L.

(2003) Biochemistry 42: 2836-2846

  • DOI: 10.1021/bi020576w

  • PubMed Abstract: 
  • The high-resolution three-dimensional structure of a Bowman Birk inhibitor, purified from snail medic seeds (Medicago scutellata) (MSTI), has been determined in solution by 1H NMR spectroscopy at pH 5.6 and 27 degrees C. The structure of MSTI compris ...

    The high-resolution three-dimensional structure of a Bowman Birk inhibitor, purified from snail medic seeds (Medicago scutellata) (MSTI), has been determined in solution by 1H NMR spectroscopy at pH 5.6 and 27 degrees C. The structure of MSTI comprises two distinct symmetric domains each composed of a three-stranded beta-sheet containing a VIb type loop, where the active sites are located. A characteristic geometry of three aromatic residues confers stability to this protein, and we observe that this feature is conserved in all the Bowman Birk inhibitors of known structure. The two active domains exhibit different conformational features: the second domain displays higher flexibility and hydrophobicity with respect to the first one, and these properties have been correlated to a lower trypsin inhibitory specificity, in agreement with titration studies that have shown a stoichiometric ratio MSTI:trypsin of 1:1.5. NMR analysis indicated that MSTI undergoes self-association at concentrations higher than 2 mM, and the residues involved in this mechanism are localized at opposite faces of the molecule, having the highest positive and negative potential, respectively, thus indicating that electrostatic intermolecular interactions are the driving forces for MSTI association. Most of the residues affected by self-association are highly conserved in BBIs from different seeds, suggesting a functional relevance for these charged superficial patches, possibly involved in the interaction with other enzymes or macromolecules, thus triggering anti-carcinogenic activity.


    Organizational Affiliation

    Istituto per lo Studio delle Macromolecole, Laboratorio NMR, CNR, Via Ampère 56, 20131, Milano, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Bowman-Birk type protease inhibitor, (MSTI)
A
62Medicago scutellataN/A
Find proteins for P80321 (Medicago scutellata)
Go to UniProtKB:  P80321
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 20 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 1MVZ Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-04-22
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance