Direct measurement of phage phi29 stiffness provides evidence of internal pressure.
Using AFM nanoindentation experiments, DNA-full phi29 phage capsids are shown to be stiffer than when empty. The presence of counterions softens full viruses in a reversible manner, indicating that pressure originates from the confined DNA. A finite element analysis of the experiments provides an estimate of the pressure of ∼40 atm inside the capsid, which is similar to theoretical predictions.
Dpto. Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049-Madrid, Spain.
Mercedes
M
Hernando-Pérez
Roberto
R
Miranda
María
M
Aznar
José L
JL
Carrascosa
Iwan A T
IA
Schaap
David
D
Reguera
Pedro J
PJ
de Pablo
D001435:Bacteriophages / Q000378:metabolism*; D004279:DNA, Viral; D018625:Microscopy, Atomic Force
D004279:DNA, Viral