1Z76 image
Entry Detail
PDB ID:
1Z76
Keywords:
Title:
Crystal structure of an acidic phospholipase A2 (BthA-I) from Bothrops jararacussu venom complexed with p-bromophenacyl bromide
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2005-03-24
Release Date:
2006-03-21
Method Details:
Experimental Method:
Resolution:
1.85 Å
R-Value Free:
0.25
R-Value Work:
0.20
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:phospholipase A2
Chain IDs:A, B
Chain Length:122
Number of Molecules:2
Biological Source:Bothrops jararacussu
Ligand Molecules
Primary Citation
Structure of BthA-I complexed with p-bromophenacyl bromide: possible correlations with lack of pharmacological activity.
Acta Crystallogr.,Sect.D 61 1670 1677 (2005)
PMID: 16301802 DOI: 10.1107/S0907444905029598

Abstact

The crystal structure of an acidic phospholipase A(2) isolated from Bothrops jararacussu venom (BthA-I) chemically modified with p-bromophenacyl bromide (BPB) has been determined at 1.85 Angstroms resolution. The catalytic, platelet-aggregation inhibition, anticoagulant and hypotensive activities of BthA-I are abolished by ligand binding. Electron-density maps permitted unambiguous identification of inhibitor covalently bound to His48 in the substrate-binding cleft. The BthA-I-BPB complex contains three structural regions that are modified after inhibitor binding: the Ca(2+)-binding loop, beta-wing and C-terminal regions. Comparison of BthA-I-BPB with two other BPB-inhibited PLA(2) structures suggests that in the absence of Na(+) ions at the Ca(2+)-binding loop, this loop and other regions of the PLA(2)s undergo structural changes. The BthA-I-BPB structure reveals a novel oligomeric conformation. This conformation is more energetically and conformationally stable than the native structure and the abolition of pharmacological activities by the ligand may be related to the oligomeric structural changes. A residue of the ;pancreatic' loop (Lys69), which is usually attributed as providing the anticoagulant effect, is in the dimeric interface of BthA-I-BPB, leading to a new hypothesis regarding the abolition of this activity by BPB.

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Primary Citation of related structures