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N‐terminal domain of P yrococcus furiosus l ‐asparaginase functions as a non‐specific, stable, molecular chaperone
Author(s) -
Tomar Rachana,
Garg Dushyant K.,
Mishra Rahul,
Thakur Ashwani K.,
Kundu Bishwajit
Publication year - 2013
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.12271
Subject(s) - pyrococcus furiosus , chemistry , thioflavin , linker , chaperone (clinical) , dimer , biochemistry , dynamic light scattering , monomer , size exclusion chromatography , biophysics , immunoglobulin light chain , enzyme , biology , materials science , nanoparticle , pathology , computer science , antibody , archaea , polymer , operating system , gene , immunology , medicine , disease , organic chemistry , alzheimer's disease , nanotechnology
The enzyme l ‐asparaginase of P yrococcus furiosus (PfA) functions as a dimer with each monomer consisting of distinct N‐ and C‐terminal domains ( NP fA and CP fA, respectively), connected by a linker. Here we present data to show that NP fA functions as a non‐specific molecular chaperone. Independently expressed NP fA refolded spontaneously whereas CP fA formed insoluble aggregates. However, when mixed and refolded together, NP fA augmented CP fA to fold with ~90% recovery. NP fA also protected a variety of substrate proteins from thermal and refolding‐mediated aggregation as monitored by a reduction in light scattering. The co‐appearance of substrate protein with NP fA in antibody pull‐down assays as well as in eluted gel filtration peaks indicated direct protein–protein interaction. These interactions were hydrophobic in nature as determined by 8‐anilino‐1‐naphthalene sulfonic acid fluorescence. NP fA inhibited polyglutamine‐mediated amyloid formation and also facilitated disintegration of preformed amyloid fibrils of amyloid‐β (1–42) as determined by reverse‐phase HPLC ‐based sedimentation assay and thioflavin T binding assays, respectively. Dynamic light scattering experiments suggested that NP fA readily assembled into polydispersed oligomeric species. With no sequence similarity to α‐crystallin or any known molecular chaperone, we present here NP fA as a novel molecular chaperone. Structured digital abstractAβ amyloid 1-42 and Aβ amyloid 1-42 bind by fluorescence technology ( View interaction ) alpha-amylase and alpha-amylase bind by light scattering ( View interaction ) Aβ amyloid 1-42 and Aβ amyloid 1-42 bind by transmission electron microscopy ( View interaction ) NPfa binds to BCA II by anti tag coimmunoprecipitation ( View interaction ) MSG and MSG bind by light scattering ( View interaction ) BCA II and BCA II bind by light scattering ( View interaction )