2AIH

1H-NMR solution structure of a trypsin/chymotrypsin Bowman-Birk inhibitor from Lens culinaris.


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 52 
  • Conformers Submitted: 20 
  • Selection Criteria: back calculated data agree with experimental NOESY spectrum 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Inhibitory properties and solution structure of a potent Bowman-Birk protease inhibitor from lentil (Lens culinaris, L) seeds.

Ragg, E.M.Galbusera, V.Scarafoni, A.Negri, A.Tedeschi, G.Consonni, A.Sessa, F.Duranti, M.

(2006) Febs J. 273: 4024-4039

  • DOI: 10.1111/j.1742-4658.2006.05406.x

  • PubMed Abstract: 
  • Bowman-Birk serine protease inhibitors are a family of small plant proteins, whose physiological role has not been ascertained as yet, while chemopreventive anticarcinogenic properties have repeatedly been claimed. In this work we present data on the ...

    Bowman-Birk serine protease inhibitors are a family of small plant proteins, whose physiological role has not been ascertained as yet, while chemopreventive anticarcinogenic properties have repeatedly been claimed. In this work we present data on the isolation of a lentil (Lens culinaris, L., var. Macrosperma) seed trypsin inhibitor (LCTI) and its functional and structural characterization. LCTI is a 7448 Da double-headed trypsin/chymotrypsin inhibitor with dissociation constants equal to 0.54 nM and 7.25 nM for the two proteases, respectively. The inhibitor is, however, hydrolysed by trypsin in a few minutes timescale, leading to a dramatic loss of its affinity for the enzyme. This is due to a substantial difference in the kon and k*on values (1.1 microM-1.s-1 vs. 0.002 microM-1.s-1), respectively, for the intact and modified inhibitor. A similar behaviour was not observed with chymotrypsin. The twenty best NMR structures concurrently showed a canonical Bowman-Birk inhibitor (BBI) conformation with two antipodal beta-hairpins containing the inhibitory domains. The tertiary structure is stabilized by ion pairs and hydrogen bonds involving the side chain and backbone of Asp10-Asp26-Arg28 and Asp36-Asp52 residues. At physiological pH, the final structure results in an asymmetric distribution of opposite charges with a negative electrostatic potential, centred on the C-terminus, and a highly positive potential, surrounding the antitryptic domain. The segment 53-55 lacks the anchoring capacity found in analogous BBIs, thus rendering the protein susceptible to hydrolysis. The inhibitory properties of LCTI, related to the simultaneous presence of two key amino acids (Gln18 and His54), render the molecule unusual within the natural Bowman-Birk inhibitor family.


    Organizational Affiliation

    Department of Agri-Food Molecular Sciences, Università degli Studi, Milano, Italy. enzio.ragg@unimi.it




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Bowman-Birk type protease inhibitor, LCTI
A
67Lens culinarisMutation(s): 0 
Find proteins for Q8W4Y8 (Lens culinaris)
Go to UniProtKB:  Q8W4Y8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 52 
  • Conformers Submitted: 20 
  • Selection Criteria: back calculated data agree with experimental NOESY spectrum 
  • Olderado: 2AIH Olderado

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-08-01
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance