Correlating Conformational Dynamics with the Von Willebrand Factor Reductase Activity of Factor H Using Single Molecule Force Measurements

Activation of proteins often involves conformational transitions, and these switches are often difficult to characterize in multidomain proteins. Full-length factor H (FH), consisting of 20 small consensus repeat domains (150 kD), is a complement control protein that regulates the activity of the al...

Full description

Saved in:
Bibliographic Details
Published in:The journal of physical chemistry. B 2018-11, Vol.122 (47), p.10653-10658
Main Authors: Wijeratne, Sithara S, Nolasco, Leticia, Li, Jingqiang, Jiang, Kevin, Moake, Joel L, Kiang, Ching-Hwa
Format: Article
Language:English
Subjects:
Catalysis
Complement Factor H - chemistry
Detergents - chemistry
HEK293 Cells
Humans
Microscopy, Atomic Force - methods
Octoxynol - chemistry
Organophosphates - chemistry
Oxidation-Reduction
Oxidoreductases - chemistry
Protein Conformation
Protein Domains
Recombinant Proteins - chemistry
Thermodynamics
von Willebrand Factor - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Activation of proteins often involves conformational transitions, and these switches are often difficult to characterize in multidomain proteins. Full-length factor H (FH), consisting of 20 small consensus repeat domains (150 kD), is a complement control protein that regulates the activity of the alternative complement pathway. Different preparations of FH can also reduce the disulfide bonds linking large Von Willebrand factor (VWF) multimers into smaller, less adhesive forms. In contrast, commercially available purified FH (pFH) has little or no VWF reductase activity unless the pFH is chemically modified by either ethylenediaminetetraacetic acid (EDTA) or urea. We used atomic force microscopy single molecule force measurements to investigate different forms of FH, including recombinant FH and pFH, in the presence or absence of EDTA and urea, and to correlate the conformational changes to its activities. We found that the FH conformation depends on the method used for sample preparation, which affects the VWF reductase activity of FH.
ISSN:1520-6106
1520-5207
DOI:10.1021/acs.jpcb.8b06153