US EPA

2711648 

Journal Article 

N-terminal domain of Pyrococcus furiosus L-asparaginase functions as a non-specific, stable, molecular chaperone 

Tomar, R; Garg, DK; Mishra, R; Thakur, AK; Kundu, B 

2013 

1 

FEBS Journal
ISSN: 1742-464X
EISSN: 1742-4658 

The FEBS Journal 

280 

11 

2688-2699 

English 

23551356 

10.1111/febs.12271 

WOS:000319413400013 

http:///www.wiley.com/WileyCDA/
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The enzyme l-asparaginase of Pyrococcusfuriosus (PfA) functions as a dimer with each monomer consisting of distinct N- and C-terminal domains (NPfA and CPfA, respectively), connected by a linker. Here we present data to show that NPfA functions as a non-specific molecular chaperone. Independently expressed NPfA refolded spontaneously whereas CPfA formed insoluble aggregates. However, when mixed and refolded together, NPfA augmented CPfA to fold with similar to 90% recovery. NPfA 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 NPfA in antibody pull-down assays as well as in eluted gel filtration peaks indicated direct proteinprotein interaction. These interactions were hydrophobic in nature as determined by 8-anilino-1-naphthalene sulfonic acid fluorescence. NPfA inhibited polyglutamine-mediated amyloid formation and also facilitated disintegration of preformed amyloid fibrils of amyloid- (142) as determined by reverse-phase HPLC-based sedimentation assay and thioflavin T binding assays, respectively. Dynamic light scattering experiments suggested that NPfA readily assembled into polydispersed oligomeric species. With no sequence similarity to -crystallin or any known molecular chaperone, we present here NPfA as a novel molecular chaperone. Structured digital abstract A amyloid 1-42 and A amyloid 1-42 bind by fluorescence technology (View interaction) alpha-amylase and alpha-amylase bind by light scattering (View interaction) A amyloid 1-42 and A 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) 

amyloid; chaperone; domain; l-asparaginase; protein aggregation