Work supported by this grant over the years helped to develop the hydrogen exchange knowledge and methods that are now widely exploited in studies of protein structure and function. Progress during this grant period has uncovered a fundamental but previously unsuspected protein property. It appears that proteins are composed of a small number of coooperative unfolding/refolding units, called foldons, and that these units form and assemble in a pathway sequence through distinct intermediate forms to progressively construct the native protein. The present application proposes to further test this hypothesis in cytochrome c. Also the generality of this behavor will be tested with other major protein models, using staphylococcal nuclease initially and then other model proteins to be selected according to specified criteria. In other work to continue the development of hydrogen exchange knowledge and its use for understanding protein dynamics and signal transfer, designed mutational perturbations will be used to study the local fluctuation mechanisms of proteins and the internal protein pathways that mediate more distant changes. All of this work will use special hydrogen exchange methods that we have developed and will depend on NMR analysis. Related hydrogen exchange experiments that depend on mass spectroscopic analysis, together with other methods, will be used to study amyloid structures and their precursor forms. The focus will be on a-synuclein initially (Parkinson's Disease) and then A|3 (Alzheimer's Disease) and will use high throughput methods among others, looking toward drug discovery efforts. The research described here aims to understand the functioning of the protein machinery of biology, both in health and in disease. This work has uncovered and is continuing to study a previously unsuspected property of protein molecules, their cooperative foldon substructure, which appears to explain how proteins fold to their active form and how they perform some other functions. The knowledge gained and the special methods developed are also being used to study the protein misfolding mechanisms that lead to devastating human and animal neurodegenerative pathologies such as Parkinson's and Alzheimer's disease and bovine spongiform encephalopathy (mad cow disease).

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM031847-25
Application #
7318884
Study Section
Macromolecular Structure and Function B Study Section (MSFB)
Program Officer
Wehrle, Janna P
Project Start
1983-12-01
Project End
2009-11-30
Budget Start
2007-12-01
Budget End
2008-11-30
Support Year
25
Fiscal Year
2008
Total Cost
$369,812
Indirect Cost
Name
University of Pennsylvania
Department
Biochemistry
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Ye, Xiang; Mayne, Leland; Kan, Zhong-Yuan et al. (2018) Folding of maltose binding protein outside of and in GroEL. Proc Natl Acad Sci U S A 115:519-524
Nguyen, David; Mayne, Leland; Phillips, Michael C et al. (2018) Reference Parameters for Protein Hydrogen Exchange Rates. J Am Soc Mass Spectrom 29:1936-1939
Tischer, Alexander; Machha, Venkata R; Frontroth, Juan P et al. (2017) Enhanced Local Disorder in a Clinically Elusive von Willebrand Factor Provokes High-Affinity Platelet Clumping. J Mol Biol 429:2161-2177
Chetty, Palaniappan S; Mayne, Leland; Lund-Katz, Sissel et al. (2017) Helical structure, stability, and dynamics in human apolipoprotein E3 and E4 by hydrogen exchange and mass spectrometry. Proc Natl Acad Sci U S A 114:968-973
Mayne, Leland (2016) Hydrogen Exchange Mass Spectrometry. Methods Enzymol 566:335-56
Hu, Wenbing; Kan, Zhong-Yuan; Mayne, Leland et al. (2016) Cytochrome c folds through foldon-dependent native-like intermediates in an ordered pathway. Proc Natl Acad Sci U S A 113:3809-14
Englander, S Walter; Mayne, Leland; Kan, Zhong-Yuan et al. (2016) Protein Folding-How and Why: By Hydrogen Exchange, Fragment Separation, and Mass Spectrometry. Annu Rev Biophys 45:135-52
Casina, Veronica C; Hu, Wenbing; Mao, Jian-Hua et al. (2015) High-resolution epitope mapping by HX MS reveals the pathogenic mechanism and a possible therapy for autoimmune TTP syndrome. Proc Natl Acad Sci U S A 112:9620-5
Englander, S Walter; Mayne, Leland (2014) The nature of protein folding pathways. Proc Natl Acad Sci U S A 111:15873-80
Hu, Wenbing; Walters, Benjamin T; Kan, Zhong-Yuan et al. (2013) Stepwise protein folding at near amino acid resolution by hydrogen exchange and mass spectrometry. Proc Natl Acad Sci U S A 110:7684-9

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