Porin-independent accumulation in Pseudomonas enables antibiotic discovery.

Gram-negative antibiotic development has been hindered by a poor understanding of the types of compounds that can accumulate within these bacteria. The presence of efflux pumps and substrate-specific outer-membrane porins in Pseudomonas aeruginosa renders this pathogen particularly challenging. As a result, there are few antibiotic options for P.

Synthesis, Self-Assembly Properties, and Degradation Characterization of a Nonionic Photocleavable Azo-Sulfide Surfactant Family.

We report the synthesis and characterization of a new family of maltose-derived nonionic surfactants that contain a photocleavable azo-sulfide linker (mAzo). The self-assembly properties of these surfactants were investigated using surface tension measurements to determine the critical micelle concentration (CMC), dynamic light scattering (DLS) to reveal the hydrodynamic radius of their self-assemblies, and transmission electron microscopy (TEM) to elucidate the micelle morphology. Ultraviolet-visible (UV-visible) spectroscopy confirmed the rapid photodegradation of these surfactants, but surface tension measurements of the surfactant solutions before and after degradation showed unusual degradation products.

Nonionic, Cleavable Surfactant for Top-Down Proteomics.

Nonionic surfactants are often used as general reagents for cell lysis enabling protein extraction, stabilization, and purification under nondenaturing conditions for downstream analysis in structural biology. However, the presence of surfactants in the sample matrix often has a deleterious effect on electrospray ionization (ESI)-mass spectrometry (MS) analysis of proteins and complexes. Here, we report a nonionic, cleavable surfactant, n-decyl-disulfide-β-D-maltoside (DSSM), for top-down proteomics.

Comprehensive Characterization of the Recombinant Catalytic Subunit of cAMP-Dependent Protein Kinase by Top-Down Mass Spectrometry.

Reversible phosphorylation plays critical roles in cell growth, division, and signal transduction. Kinases which catalyze the transfer of γ-phosphate groups of nucleotide triphosphates to their substrates are central to the regulation of protein phosphorylation and are therefore important therapeutic targets. Top-down mass spectrometry (MS) presents unique opportunities to study protein kinases owing to its capabilities in comprehensive characterization of proteoforms that arise from alternative splicing, sequence variations, and post-translational modifications.