TY - JOUR
T1 - Mechanical properties of murine leukemia virus particles
T2 - Effect of maturation
AU - Kol, Nitzan
AU - Gladnikoff, Micha
AU - Barlam, David
AU - Shneck, Roni Z.
AU - Rein, Alan
AU - Rousso, Itay
N1 - Funding Information:
This work was supported by a grant from the Eisenberg-Keefer Fund for New Scientists, the Kimmelman Center for Macromolecular Assemblies, and in part by the Intramural Research Program of the National Institutes of Health, National Cancer Institute, Center for Cancer Research. I.R. is the incumbent of the Robert Edward and Roselyn Rich Manson Career Development Chair.
PY - 2006/1/1
Y1 - 2006/1/1
N2 - After budding from the host cell, retroviruses undergo a process of internal reorganization called maturation, which is prerequisite to infectivity. Viral maturation is accompanied by dramatic morphological changes, which are poorly understood in physical/mechanistic terms. Here, we study the mechanical properties of live mature and immature murine leukemia virus particles by indentation-type experiments conducted with an atomic force microscope tip. We find that both mature and immature particles have an elastic shell. Strikingly, the virus shell is twofold stiffer in the immature (0.68 N/m) than the mature (0.31 N/m) form. However, finite-element simulation shows that the average Young's modulus of the immature form is more than fourfold lower than that of the mature form. This finding suggests that per length unit, the protein-protein interactions in the mature shell are stronger than those in the immature shell. We also show that the mature virus shell is brittle, since it can be broken by application of large loading forces, by firm attachment to a substrate, or by repeated application of force. Our results are the first analysis of the mechanical properties of an animal virus, and demonstrate a linkage between virus morphology and mechanical properties.
AB - After budding from the host cell, retroviruses undergo a process of internal reorganization called maturation, which is prerequisite to infectivity. Viral maturation is accompanied by dramatic morphological changes, which are poorly understood in physical/mechanistic terms. Here, we study the mechanical properties of live mature and immature murine leukemia virus particles by indentation-type experiments conducted with an atomic force microscope tip. We find that both mature and immature particles have an elastic shell. Strikingly, the virus shell is twofold stiffer in the immature (0.68 N/m) than the mature (0.31 N/m) form. However, finite-element simulation shows that the average Young's modulus of the immature form is more than fourfold lower than that of the mature form. This finding suggests that per length unit, the protein-protein interactions in the mature shell are stronger than those in the immature shell. We also show that the mature virus shell is brittle, since it can be broken by application of large loading forces, by firm attachment to a substrate, or by repeated application of force. Our results are the first analysis of the mechanical properties of an animal virus, and demonstrate a linkage between virus morphology and mechanical properties.
UR - http://www.scopus.com/inward/record.url?scp=33745728287&partnerID=8YFLogxK
U2 - 10.1529/biophysj.105.079657
DO - 10.1529/biophysj.105.079657
M3 - Article
AN - SCOPUS:33745728287
SN - 0006-3495
VL - 91
SP - 767
EP - 774
JO - Biophysical Journal
JF - Biophysical Journal
IS - 2
ER -