scholarly journals Structural insights into protein folding, stability and activity using in vivo perdeuteration of hen egg-white lysozyme

IUCrJ ◽  
2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Joao Ramos ◽  
Valerie Laux ◽  
Michael Haertlein ◽  
Elisabetta Boeri Erba ◽  
Katherine E. McAuley ◽  
...  

This structural and biophysical study exploited a method of perdeuterating hen egg-white lysozyme based on the expression of insoluble protein in Escherichia coli followed by in-column chemical refolding. This allowed detailed comparisons with perdeuterated lysozyme produced in the yeast Pichia pastoris, as well as with unlabelled lysozyme. Both perdeuterated variants exhibit reduced thermal stability and enzymatic activity in comparison with hydrogenated lysozyme. The thermal stability of refolded perdeuterated lysozyme is 4.9°C lower than that of the perdeuterated variant expressed and secreted in yeast and 6.8°C lower than that of the hydrogenated Gallus gallus protein. However, both perdeuterated variants exhibit a comparable activity. Atomic resolution X-ray crystallographic analyses show that the differences in thermal stability and enzymatic function are correlated with refolding and deuteration effects. The hydrogen/deuterium isotope effect causes a decrease in the stability and activity of the perdeuterated analogues; this is believed to occur through a combination of changes to hydrophobicity and protein dynamics. The lower level of thermal stability of the refolded perdeuterated lysozyme is caused by the unrestrained Asn103 peptide-plane flip during the unfolded state, leading to a significant increase in disorder of the Lys97–Gly104 region following subsequent refolding. An ancillary outcome of this study has been the development of an efficient and financially viable protocol that allows stable and active perdeuterated lysozyme to be more easily available for scientific applications.

Nitric Oxide ◽  
2012 ◽  
Vol 27 ◽  
pp. S37-S38
Author(s):  
Maria Gómez-Mingot ◽  
Luis A. Alcaraz ◽  
Antonio Donaire ◽  
Jesús Iniesta ◽  
Vicente Montiel

Author(s):  
Joao Ramos ◽  
Valerie Laux ◽  
Michael Haertlein ◽  
V. Trevor Forsyth ◽  
Estelle Mossou ◽  
...  

The biological function of a protein is intimately related to its structure and dynamics, which in turn are determined by the way in which it has been folded. In vitro refolding is commonly used for the recovery of recombinant proteins that are expressed in the form of inclusion bodies and is of central interest in terms of the folding pathways that occur in vivo. Here, biophysical data are reported for in vitro-refolded hydrogenated hen egg-white lysozyme, in combination with atomic resolution X-ray diffraction analyses, which allowed detailed comparisons with native hydrogenated and refolded perdeuterated lysozyme. Distinct folding modes are observed for the hydrogenated and perdeuterated refolded variants, which are determined by conformational changes to the backbone structure of the Lys97–Gly104 flexible loop. Surprisingly, the structure of the refolded perdeuterated protein is closer to that of native lysozyme than that of the refolded hydrogenated protein. These structural differences suggest that the observed decreases in thermal stability and enzymatic activity in the refolded perdeuterated and hydrogenated proteins are consequences of the macromolecular deuteration effect and of distinct folding dynamics, respectively. These results are discussed in the context of both in vitro and in vivo folding, as well as of lysozyme amyloidogenesis.


RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 10973-10984 ◽  
Author(s):  
W. Gospodarczyk ◽  
M. Kozak

The formation of amyloid plaques is being intensively studied, as this process underlies severe human diseases, including Alzheimer's disease, and the exact mechanism of this specific aggregation has not been resolved yet.


2012 ◽  
Vol 95 ◽  
pp. 103-108 ◽  
Author(s):  
Michal Ciolkowski ◽  
Bartłomiej Pałecz ◽  
Dietmar Appelhans ◽  
Brigitte Voit ◽  
Barbara Klajnert ◽  
...  

1997 ◽  
Vol 94 ◽  
pp. 356-364 ◽  
Author(s):  
M Faraggi ◽  
E Bettelheim ◽  
M Weinstein

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