Biochemistry
Biochemistry
5 years ago

Stepwise Assembly of β-Sheet Structure during the Folding of an SH3 Domain Revealed by a Pulsed Hydrogen Exchange Mass Spectrometry Study

Stepwise Assembly of β-Sheet Structure during the Folding of an SH3 Domain Revealed by a Pulsed Hydrogen Exchange Mass Spectrometry Study
Nilesh Aghera, Jayant B. Udgaonkar
Dissecting temporally the sequence of secondary structural changes, and determining how these specific changes modulate conformational heterogeneity, remain major goals of protein folding studies. In this study, the folding of the SH3 domain of PI3 kinase has been characterized using pulsed hydrogen exchange mass spectrometry (HX-MS). The folding could be described as a four-state process, U ↔ IVE ↔ IE ↔ N, where IVE and IE are structurally heterogeneous intermediate ensembles. Compared to U, early intermediate IVE has a marginally increased level of protection against HX of amides along the entire length of the polypeptide. Sequential assembly into β-sheet structure has been resolved temporally. Three of the five β-strands acquire nativelike structure before the rate-limiting step. β-Strands 2 and 5 acquire nativelike structure in IVE, while β-strand 4 does so in IE. β-Strand 1 acquires nativelike structure only during the last step of the folding process. Hence, the HX-MS study has resolved the order of assembly of the β-strands for the formation of the two β-sheets, which previous studies utilizing Φ-value analysis of several different SH3 domains had been unable to accomplish. Moreover, it is shown that structural heterogeneity decreases in a stepwise manner during the three stages of folding.

Publisher URL: http://dx.doi.org/10.1021/acs.biochem.7b00374

DOI: 10.1021/acs.biochem.7b00374

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.