Correction for 'Fmoc-diphenylalanine hydrogels: understanding the variability in reported mechanical properties' by Jaclyn Raeburn , , 2012, , 1168-1174, https://doi.org/10.1039/C1SM06929B.
View Article and Find Full Text PDFDespite the central role of division in bacterial physiology, how division proteins work together as a nanoscale machine to divide the cell remains poorly understood. Cell division by cell wall synthesis proteins is guided by the cytoskeleton protein FtsZ, which assembles at mid-cell as a dense Z-ring formed of treadmilling filaments. However, although FtsZ treadmilling is essential for cell division, the function of FtsZ treadmilling remains unclear.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2019
Bacterial cell division and peptidoglycan (PG) synthesis are orchestrated by the coordinated dynamic movement of essential protein complexes. Recent studies show that bidirectional treadmilling of FtsZ filaments/bundles is tightly coupled to and limiting for both septal PG synthesis and septum closure in some bacteria, but not in others. Here we report the dynamics of FtsZ movement leading to septal and equatorial ring formation in the ovoid-shaped pathogen, Conventional and single-molecule total internal reflection fluorescence microscopy (TIRFm) showed that nascent rings of FtsZ and its anchoring and stabilizing proteins FtsA and EzrA move out from mature septal rings coincident with MapZ rings early in cell division.
View Article and Find Full Text PDFThe methods currently available to deliver functional labels and drugs to the cell cytosol are inefficient and this constitutes a major obstacle to cell biology (delivery of sensors and imaging probes) and therapy (drug access to the cell internal machinery). As cell membranes are impermeable to most molecular cargos, viral peptides have been used to bolster their internalisation through endocytosis and help their release to the cytosol by bursting the endosomal vesicles. However, conflicting results have been reported on the extent of the cytosolic delivery achieved.
View Article and Find Full Text PDFA detailed understanding of cellular interactions with superparamagnetic iron oxide nanoparticles (SPIONs) is critical when their biomedical applications are considered. We demonstrate how photothermal microscopy can be used to follow the cellular uptake of SPIONs by direct imaging of the iron oxide core. This offers two important advantages when compared with current strategies employed to image magnetic cores: first, it is nondestructive and is therefore suitable for studies of live cells and, second, it offers a higher sensitivity and resolution, thus allowing for the identification of low levels of SPIONs within a precise subcellular location.
View Article and Find Full Text PDFFmoc-diphenylalanine (FmocFF or FmocPhePhe) is an important low molecular weight hydrogelator. Gelation can be induced by either lowering the pH of an aqueous solution of FmocFF or by the addition of water to a solution of FmocFF in a solvent such as DMSO. Despite the volume of literature on FmocFF, the mechanical properties reported for the gels vary significantly over four orders of magnitude and the origins of this variability is unclear.
View Article and Find Full Text PDFFunctional nanomaterials have recently attracted strong interest from the biology community, not only as potential drug delivery vehicles or diagnostic tools, but also as optical nanomaterials. This is illustrated by the explosion of publications in the field with more than 2,000 publications in the last 2 years (4,000 papers since 2000; from ISI Web of Knowledge, 'nanoparticle and cell' hit). Such a publication boom in this novel interdisciplinary field has resulted in papers of unequal standard, partly because it is challenging to assemble the required expertise in chemistry, physics, and biology in a single team.
View Article and Find Full Text PDFUnderstanding the dynamic fate and interactions of bioconjugated nanoparticles within living cells and organisms is a prerequisite for their use as in situ sensors or actuators. While recent research has provided indications on the effect of size, shape, and surface properties of nanoparticles on their internalization by living cells, the biochemical fate of the nanoparticles after internalization has been essentially unknown. Here we show that, upon internalization in a wide range of mammalian cells, biological molecules attached to the nanoparticles are degraded within the endosomal compartments through peptide cleavage by the protease cathepsin L.
View Article and Find Full Text PDF