This title appears in the Scientific Report :
2016
Please use the identifier:
http://dx.doi.org/10.1021/acs.biochem.5b01028 in citations.
The Nedd4-1 WW Domain Recognizes the PY Motif Peptide through Coupled Folding and Binding Equilibria.
The Nedd4-1 WW Domain Recognizes the PY Motif Peptide through Coupled Folding and Binding Equilibria.
The four WW domains of human Nedd4-1 (neuronal precursor cell expressed developmentally downregulated gene 4-1) interact with the PPxY (PY) motifs of the human epithelial Na(+) channel (hENaC) subunits, with the third WW domain (WW3*) showing the highest affinity. We have shown previously that the α...
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Personal Name(s): | Panwalkar, Vineet |
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Neudecker, Philipp / Schmitz, Michael / Lecher, Justin / Schulte, Marianne / Medini, Karima / Stoldt, Matthias / Brimble, Margaret A / Willbold, Dieter / Dingley, Andrew J (Corresponding author) | |
Contributing Institute: |
Strukturbiochemie; ICS-6 |
Published in: | Biochemistry, 55 (2016) 4, S. 659 - 674 |
Imprint: |
Columbus, Ohio
American Chemical Society
2016
|
PubMed ID: |
26685112 |
DOI: |
10.1021/acs.biochem.5b01028 |
Document Type: |
Journal Article |
Research Program: |
Physical Basis of Diseases |
Publikationsportal JuSER |
The four WW domains of human Nedd4-1 (neuronal precursor cell expressed developmentally downregulated gene 4-1) interact with the PPxY (PY) motifs of the human epithelial Na(+) channel (hENaC) subunits, with the third WW domain (WW3*) showing the highest affinity. We have shown previously that the α-hENaC PY motif binding interface of WW3* undergoes conformational exchange on the millisecond time scale, indicating that conformational sampling plays a role in peptide recognition. To further understand this role, the structure and dynamics of hNedd4-1 WW3* were investigated. The nuclear Overhauser effect-derived structure of apo-WW3* resembles the domain in complex with the α-hENaC peptide, although particular side chain conformations change upon peptide binding, which was further investigated by molecular dynamics simulations. Model-free analysis of the (15)N nuclear magnetic resonance spin relaxation data showed that the apo and peptide-bound states of WW3* have similar backbone picosecond to nanosecond time scale dynamics. However, apo-WW3* exhibits pronounced chemical exchange on the millisecond time scale that is quenched upon peptide binding. (1)HN and (15)N Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments at various temperatures revealed that apo-WW3* exists in an equilibrium between the natively folded peptide binding-competent state and a random coil-like denatured state. The thermodynamics of the folding equilibrium was determined by fitting a thermal denaturation profile monitored by circular dichroism spectroscopy in combination with the CPMG data, leading to the conclusion that the unfolded state is populated to ∼20% at 37 °C. These results show that the binding of the hNedd4-1 WW3* domain to α-hENaC is coupled to the folding equilibrium. |