help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Originally published as Biophys J. BioFAST on August 17, 2007.
doi:10.1529/biophysj.107.112102
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
biophysj.107.112102v1
93/12/4392    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Weiss, W. F.
Right arrow Articles by Roberts, C. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Weiss, W. F., IV
Right arrow Articles by Roberts, C. J.
Biophysical Journal 93:4392-4403 (2007)
© 2007 The Biophysical Society

Nonnative Protein Polymers: Structure, Morphology, and Relation to Nucleation and Growth

William F. Weiss, IV, Travis K. Hodgdon, Eric W. Kaler, Abraham M. Lenhoff and Christopher J. Roberts

Department of Chemical Engineering, University of Delaware, Newark, Delaware

Correspondence: Address reprint requests to Christopher J. Roberts, Tel.: 302-831-0838; E-mail: cjr{at}udel.edu.

Thermally induced aggregates of {alpha}-chymotrypsinogen A and bovine granulocyte-colony stimulating factor in acidic solutions were characterized by a combination of static and dynamic light scattering, spectroscopy, transmission electron microscopy, and monomer loss kinetics. The resulting soluble, high-molecular weight aggregates (~103–105 kDa) are linear, semiflexible polymer chains that do not appreciably associate with one another under the conditions at which they were formed, with classic power-law scaling of the radius of gyration and hydrodynamic radius with weight-average molecular weight (Mw). Aggregates in both systems are composed of nonnative monomers with elevated levels of β-sheet secondary structure, and bind thioflavine T. In general, the aggregate size distributions showed low polydispersity by light scattering. Together with the inverse scaling of Mw with protein concentration, the results clearly indicate that aggregation proceeds via nucleated (chain) polymerization. For {alpha}-chymotrypsinogen A, the scaling behavior is combined with the kinetics of aggregation to deduce separate values for the characteristic timescales for nucleation ({tau}n) and growth ({tau}g), as well as the stoichiometry of the nucleus (x). The analysis illustrates a general procedure to noninvasively and quantitatively determine {tau}n, {tau}g, and x for soluble (chain polymer) aggregates, as well as the relationship between {tau}n/{tau}g and aggregate Mw.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the Biophysical Society.