| Comments |
"Of equal interest, the ratio {R[g](untreated)-R[g](+DNP)}/R[g](+DNP) decreased toward 0 as size decreased (Figure 3E), with an estimated
intercept near 30–40 nm assuming a linear relationship.
This finding suggests that cytoplasmic components smaller
than this estimated size are not affected by metabolism-dependent
motion...[researchers] show that, above a certain size scale
(~30 nm), the bacterial cytoplasm behaves differently from a
simple (viscous) fluid. Instead, it displays striking features
(such as non-Gaussian distributions of displacements with
long tails, nonergodicity, caging, and dynamic heterogeneity
Figures 4B, 4E, 5A, and 6) that are characteristic of colloidal
glasses (Cipelletti and Ramos, 2005 Hunter and Weeks, 2012)...Based on [researchers'] rough
critical size estimation, [they] expect that cytoplasmic constituents
=30nm will be subject to metabolism-dependent motion. This
implies that proteins, which typically have a size <10 nm, will
not be affected, consistent with the minimal effect of DNP on
the apparent diffusion of free GFP in C. crescentus (Montero
Llopis et al., 2012)." R[g]=radius of gyration. (DNP+)=DNP (2,4-dinitrophenol) treated condition=energy depleted |