2 research outputs found
Nanoglassified, Optically-Active Monolayer Films of Gold Nanoparticles for in Situ Orthogonal Detection by Localized Surface Plasmon Resonance and Surface-Assisted Laser Desorption/Ionization-MS
Localized
surface plasmon resonance (LSPR) represents a sensitive and versatile
method for detection of biomolecules in a label-free fashion, but
identification of bound analytes can be challenging with LSPR alone,
especially for samples in a complex medium. We report the fabrication
of an optically active, plasmonic film of gold nanoparticles by using
a self-assembly and calcination process, which offers orthogonal measurements
enabling multifaceted characterization on the same surface with LSPR
and surface-assisted laser desorption/ionization mass spectrometry.
This proof-of-concept study involves plasmonic characterization of
the fabricated nanofilm, real-time monitoring of vesicle–surface
interactions toward formation of fluid lipid bilayer, and mass spectrometric
analysis of peptides and cytochrome c digest. This multifunction-enabling
surface material can yield complementary analytical information, providing
new tools for comprehensive analysis of biomolecular samples
Quantitative Profiling of Protein S‑Glutathionylation Reveals Redox-Dependent Regulation of Macrophage Function during Nanoparticle-Induced Oxidative Stress
Engineered nanoparticles (ENPs) are
increasingly utilized for commercial
and medical applications; thus, understanding their potential adverse
effects is an important societal issue. Herein, we investigated protein
S-glutathionylation (SSG) as an underlying regulatory mechanism by
which ENPs may alter macrophage innate immune functions, using a quantitative
redox proteomics approach for site-specific measurement of SSG modifications.
Three high-volume production ENPs (SiO<sub>2</sub>, Fe<sub>3</sub>O<sub>4</sub>, and CoO) were selected as representatives which induce
low, moderate, and high propensity, respectively, to stimulate cellular
reactive oxygen species (ROS) and disrupt macrophage function. The
SSG modifications identified highlighted a broad set of redox sensitive
proteins and specific Cys residues which correlated well with the
overall level of cellular redox stress and impairment of macrophage
phagocytic function (CoO > Fe<sub>3</sub>O<sub>4</sub> ≫
SiO<sub>2</sub>). Moreover, our data revealed pathway-specific differences
in susceptibility to SSG between ENPs which induce moderate <i>versus</i> high levels of ROS. Pathways regulating protein translation
and protein stability indicative of ER stress responses and proteins
involved in phagocytosis were among the most sensitive to SSG in response
to ENPs that induce subcytoxic levels of redox stress. At higher levels
of redox stress, the pattern of SSG modifications displayed reduced
specificity and a broader set pathways involving classical stress
responses and mitochondrial energetics (<i>e.g.,</i> glycolysis)
associated with apoptotic mechanisms. An important role for SSG in
regulation of macrophage innate immune function was also confirmed
by RNA silencing of glutaredoxin, a major enzyme which reverses SSG
modifications. Our results provide unique insights into the protein
signatures and pathways that serve as ROS sensors and may facilitate
cellular adaption to ENPs, <i>versus</i> intracellular targets
of ENP-induced oxidative stress that are linked to irreversible cell
outcomes