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Structural characterization of BEX3 (brain expressed X‐linked) (755.1)
Author(s) -
Almeida Marcius,
Raymundo Diana,
Cabral Katia Maria
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.755.1
Subject(s) - circular dichroism , chemistry , surface plasmon resonance , biophysics , size exclusion chromatography , crystallography , escherichia coli , binding site , protein structure , biochemistry , biology , enzyme , nanoparticle , nanotechnology , materials science , gene
The aim of this work is to characterize BEX3 at molecular level. BEX3 is a p75NTR‐associated protein that mediates apoptosis in response to Nerve Growth Factor, by interacting with the intracellular death domain of p75‐NTR. Besides a small number of studies validating the interaction of BEX3 and p75‐NTR in vivo, very little is known about the interaction of these proteins. For instance, the 3D structure of BEX3 is still uncharacterized. These proteins have been expressed heterologously at high level in the soluble fraction of Escherichia coli, and them purified by nickel affinity and gel filtration chromatography. The protein was characterized by solution nuclear magnetic resonance, circular dichroism, fluorescence spectroscopy, atomic force microscopy, small‐angle X‐ray scattering, partial proteolysis and partial cross‐linking. Surface plasmon resonance binding experiments using Biacore X system reveled binding and dissociation of BEX3/p75‐NTR with Kd within nanomolar range, which fits to an one‐site binding curve (R2=0.9999). The 3D structure of BEX3 has high content of flexibly disordered regions in addition to residual alpha‐helix structure and folded hydrophobic core at its C‐terminus. We discuss the capacity of this protein to form high‐order oligomers to avoid aggregation. Grant Funding Source : Supported by FAPEJ and CNPq.