Optimized Design and Synthesis of a Cell-Permeable Biarsenical Cyanine Probe for Imaging Tagged Cytosolic Bacterial Proteins

To optimize cellular delivery and specific labeling of tagged cytosolic proteins by biarsenical fluorescent probes built around a cyanine dye (Cy3) scaffold, we have systematically varied the polarity of the N-alkyl chain (i.e., 4–5 methylene groups appended by a sulfonate or methoxy ester moiety) and arsenic capping reagent (ethanedithiol versus benzenedithiol). Optimal live-cell labeling and visualization of tagged cytosolic proteins is reported using an ethanedithiol capping reagent with the uncharged methoxy ester functionalized N-alkyl chains. These measurements demonstrate the general utility of this new class of photostable and highly fluorescent biarsenical probes based on the cyanine dye scaffold for in vivo labeling of tagged cellular proteins for live cell imaging measurements of protein dynamics

Synthesis of a Targeted Biarsenical Cy3-Cy5 Affinity Probe for Super-resolution Fluorescence Imaging

Photoswitchable fluorescent probes capable of the targeted labeling of tagged proteins are of significant interest due to their ability to enable <i>in situ</i> imaging of protein complexes within native biomolecular assemblies. Here we describe the synthesis of a fluorescent probe (<b>AsCy3Cy5</b>) and demonstrate the targeted labeling and super-resolution imaging of a tagged protein within a supramolecular protein complex

Creating a safer workplace: A linkage model for labour‒management partnership, psychological safety, collaborative industrial relations climate and organisational occupational and health safety performance

This study takes a mutual gains perspective to investigate how a labour‒management partnership (LMP) impacts organisational occupational and health safety (OHS) performance and creates a safe workplace. It develops a model linking employee psychological safety with a collaborative industrial relations (IR) climate and ultimately organisational OHS performance. The research context is China ‒ where LMP is driven by the Party-state in managing labour relations. To test the proposed linkage model, multi-level structural equation modelling is conducted, using matched employer‒employee data from 205 companies and 7229 employees in an industrial park in the Yangtze River Delta. The results support the use of the linkage model, demonstrating that partnership decision-making increases psychological safety, in turn developing a collaborative IR climate, ultimately reducing the number of accidents. This study contributes to partnership research by exploring the underlying mechanisms of how a partnership arising from the logic of neo-pluralism successfully delivers mutual gains for employees and employers in a non-pluralist context. It has wider implications for collaborative management and OHS management in a developing country.</p

Synthesis and Application of an Environmentally Insensitive Cy3-Based Arsenical Fluorescent Probe To Identify Adaptive Microbial Responses Involving Proximal Dithiol Oxidation

Reversible disulfide oxidation between proximal cysteines in proteins represents a common regulatory control mechanism to modulate flux through metabolic pathways in response to changing environmental conditions. To enable <i>in vivo</i> measurements of cellular redox changes linked to disulfide bond formation, we have synthesized a cell-permeable thiol-reactive affinity probe (TRAP) consisting of a monosubstituted cyanine dye derivatized with arsenic (i.e., TRAP_Cy3) to trap and visualize dithiols in cytosolic proteins. Alkylation of reactive thiols prior to displacement of the bound TRAP_Cy3 by ethanedithiol permits facile protein capture and mass spectrometric identification of proximal reduced dithiols to the exclusion of individual cysteines. Applying TRAP_Cy3 to evaluate cellular responses to increases in oxygen and light levels in the photosynthetic microbe <i>Synechococcus</i> sp. PCC7002, we observe large decreases in the abundance of reduced dithiols in cellular proteins, which suggest redox-dependent mechanisms involving the oxidation of proximal disulfides. Under these same growth conditions that result in the oxidation of proximal thiols, there is a reduction in the abundance of post-translational oxidative protein modifications involving methionine sulfoxide and nitrotyrosine. These results suggest that the redox status of proximal cysteines responds to environmental conditions, acting to regulate metabolic flux and minimize the formation of reactive oxygen species to decrease oxidative protein damage