Feather corticosterone is lower in translocated and historical populations of the endangered Laysan duck ().

Identifying reliable bioindicators of population status is a central goal of conservation physiology. Physiological stress measures are often used as metrics of individual health and can assist in managing endangered species if linked to fitness traits. We analysed feather corticosterone, a cumulative physiological stress metric, of individuals from historical, translocated, and source populations of an endangered endemic Hawaiian bird, the Laysan duck ().

Elevated lead (Pb) in urban European starling (Sturnus vulgaris) feathers is not correlated to physiology or behavior.

Urbanization is rapidly changing the environment and creating new challenges in the lives of animals across the globe. Anthropogenic contaminants-like heavy metals-can persist within the environment for prolonged periods of time and present a widespread problem for those living near contaminated areas. Lead (Pb) was a commonly used heavy metal that continues to threaten the health of all organisms despite being phased out, especially in urban areas where historical use was more common.

Determining the Location of the α-Synuclein Dimer Interface Using Native Top-Down Fragmentation and Isotope Depletion-Mass Spectrometry.

α-Synuclein (αSyn), a 140-residue intrinsically disordered protein, comprises the primary proteinaceous component of pathology-associated Lewy body inclusions in Parkinson's disease (PD). Due to its association with PD, αSyn is studied extensively; however, the endogenous structure and physiological roles of this protein are yet to be fully understood. Here, ion mobility-mass spectrometry and native top-down electron capture dissociation fragmentation have been used to elucidate the structural properties associated with a stable, naturally occurring dimeric species of αSyn.

The present and potential future of aqueous mercury preservation: a review.

Mercury is considered to be one of the most toxic elements to humans. Due to pollution from industry and artisanal gold mining, mercury species are present globally in waters used for agriculture, aquaculture, and drinking water. This review summarises methods reported for preserving mercury species in water samples and highlights the associated hazards and issues with each.

Validation of a quantitative liquid chromatography/hybrid quadrupole-linear ion trap MS/MS method for carfentanil and caffeine in a live human epidermis model.

Rationale: Carfentanil, an opioid 10K times more potent than morphine, has no licit clinical use. A powerful CNS depressant, it has been identified increasingly as the cause of overdose death in the United States. Because it is highly lipophilic, the law enforcement and medical communities have been concerned that responding personnel could be percutaneously exposed and that exposure could be enhanced with the use of alcohol-containing hand sanitizers.

The development of behavioral and endocrine coping styles in nestlings from urban and rural sites.

Urbanization is increasing globally and altering the stressors that animals face in their everyday lives. Organisms often differ in their coping styles-both behavioral and endocrine-across urban to rural habitats. For example, urban animals are often bolder, more exploratory, and mount stronger glucocorticoid stress responses compared to their rural counterparts.

Atmospheric Benzothiazoles in a Coastal Marine Environment.

Organic emissions from coastal waters play an important but poorly understood role in atmospheric chemistry in coastal regions. A mesocosm experiment focusing on facilitated biological blooms in coastal seawater, SeaSCAPE (Sea Spray Chemistry and Particle Evolution), was performed to study emission of volatile gases, primary sea spray aerosol, and formation of secondary marine aerosol as a function of ocean biological and chemical processes. Here, we report observations of aerosol-phase benzothiazoles in a marine atmospheric context with complementary measurements of dissolved-phase benzothiazoles.

Improved N- and C-Terminal Sequencing of Proteins by Combining Positive and Negative Ion MALDI In-Source Decay Mass Spectrometry.

The development of various ionization and fragmentation techniques has been of key importance for establishing mass spectrometry (MS) as a powerful tool for protein characterization. One example of this is matrix-assisted laser desorption/ionization (MALDI) combined with in-source decay (ISD) fragmentation that allows mapping of N- and C-terminal regions of large proteins without the need for proteolysis. Positive ion mode ISD fragments are commonly assigned in the mass region above / 1000, while MALDI matrix ions generally hamper the detection of smaller singly charged fragments.

Evaluation of Sibling and Twin Fragment Ions Improves the Structural Characterization of Proteins by Top-Down MALDI In-Source Decay Mass Spectrometry.

Comprehensive determination of primary sequence and identification of post-translational modifications (PTMs) are key elements in protein structural analysis. Various mass spectrometry (MS) based fragmentation techniques are powerful approaches for mapping both the amino acid sequence and PTMs; one of these techniques is matrix-assisted laser desorption/ionization (MALDI), combined with in-source decay (ISD) fragmentation and Fourier-transform ion cyclotron resonance (FT-ICR) MS. MALDI-ISD MS protein analysis involves only minimal sample preparation and does not require spectral deconvolution.

Isotope Depletion Mass Spectrometry (ID-MS) for Accurate Mass Determination and Improved Top-Down Sequence Coverage of Intact Proteins.

Top-down mass spectrometry (MS) is an increasingly important technique for protein characterization. However, in many biological MS experiments, the practicality of applying top-down methodologies is still limited at higher molecular mass. In large part, this is due to the detrimental effect resulting from the partitioning of the mass spectral signal into an increasing number of isotopic peaks as molecular mass increases.

Monitoring glycation levels of a bispecific monoclonal antibody at subunit level by ultrahigh-resolution MALDI FT-ICR mass spectrometry.

Bispecific monoclonal antibodies (BsAbs) are engineered proteins with multiple functionalities and properties. The "bi-specificity" of these complex biopharmaceuticals is a key characteristic for the development of novel and more effective therapeutic strategies. The high structural complexity of BsAbs poses a challenge to the analytical methods needed for their characterization.

Phase relationships in two-dimensional mass spectrometry.

Two-dimensional mass spectrometry (2D MS) is a data-independent tandem mass spectrometry technique in which precursor and fragment ion species can be correlated without the need for prior ion isolation. The behavior of phase in 2D Fourier transform mass spectrometry is investigated with respect to the calculation of phase-corrected absorption-mode 2D mass spectra. 2D MS datasets have a phase that is defined differently in each dimension.

A Light-Activated Acyl Carrier Protein "Trap" for Intermediate Capture in Type II Iterative Polyketide Biocatalysis.

A discrete acyl carrier protein (ACP) bearing a photolabile nonhydrolysable carba(dethia) malonyl pantetheine cofactor was chemoenzymatically prepared and utilised for the trapping of biosynthetic polyketide intermediates following light activation. From the in vitro assembly of the polyketides SEK4 and SEK4b, by the type II actinorhodin "minimal" polyketide synthase (PKS), a range of putative ACP-bound diketides, tetraketides, pentaketides and hexaketides were identified and characterised by FT-ICR-MS, providing direct insights on active site accessibility and substrate processing for this enzyme class.

Increased throughput and ultra-high mass resolution in DESI FT-ICR MS imaging through new-generation external data acquisition system and advanced data processing approaches.

Desorption electrospray ionisation-mass spectrometry imaging (DESI-MSI) is a powerful imaging technique for the analysis of complex surfaces. However, the often highly complex nature of biological samples is particularly challenging for MSI approaches, as options to appropriately address molecular complexity are limited. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) offers superior mass accuracy and mass resolving power, but its moderate throughput inhibits broader application.

Structural Analysis of Monoclonal Antibodies by Ultrahigh Resolution MALDI In-Source Decay FT-ICR Mass Spectrometry.

The emergence of complex protein therapeutics in general and monoclonal antibodies (mAbs) in particular have stimulated analytical chemists to develop new methods and strategies for their structural characterization. Mass spectrometry plays a key role in providing information on the primary amino acid sequence, post-translational modifications, and other structure characteristics that must be monitored during the manufacturing process and subsequent quality control assessment. In this study, we present a novel method that allows structural characterization of mAbs based on MALDI in-source decay (ISD) fragmentation, coupled with Fourier transform ion cyclotron resonance (FT-ICR) MS.

Rapid Food Product Analysis by Surface Acoustic Wave Nebulization Coupled Mass Spectrometry.

Rapid food product analysis is of great interest for quality control and assurance during the production process. Conventional quality control protocols require time and labor intensive sample preparation for analysis by state-of-the-art analytical methods. To reduce overall cost and facilitate rapid qualitative assessments, food products need to be tested with minimal sample preparation.

Correction to: Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate.

In the preceding article "Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate" by Oyler et al., an error in the J5 E. coli LPS chemical structure (Figs.

Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate.

Recent advances in lipopolysaccharide (LPS) biology have led to its use in drug discovery pipelines, including vaccine and vaccine adjuvant discovery. Desirable characteristics for LPS vaccine candidates include both the ability to produce a specific antibody titer in patients and a minimal host inflammatory response directed by the innate immune system. However, in-depth chemical characterization of most LPS extracts has not been performed; hence, biological activities of these extracts are unpredictable.

Native-MS Analysis of Monoclonal Antibody Conjugates by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

Antibody-drug conjugates (ADCs) are an important class of therapeutic molecule currently being used to treat HER2-positive metastatic breast cancer, relapsed or refractory Hodgkin lymphoma, systemic anaplastic large cell lymphoma, relapsed or refractory B-cell precursor acute lymphoblastic leukemia, and acute myeloid leukemia. An ADC typically consists of a small molecule or peptide-based cytotoxic moiety covalently linked, via lysine or cysteine residues, to a monoclonal antibody (mAb) scaffold. Mass spectrometric (MS) characterization of these molecules affords highly accurate molecular weight (MW) and drug-to-antibody ratio (DAR) determination and is typically performed using orthogonal acceleration time-of-flight (oa-ToF) analyzers and more recently, Orbitrap instruments.

Autopiquer - a Robust and Reliable Peak Detection Algorithm for Mass Spectrometry.

We present a simple algorithm for robust and unsupervised peak detection by determining a noise threshold in isotopically resolved mass spectrometry data. Solving this problem will greatly reduce the subjective and time-consuming manual picking of mass spectral peaks and so will prove beneficial in many research applications. The Autopiquer approach uses autocorrelation to test for the presence of (isotopic) structure in overlapping windows across the spectrum.

Norharmane Matrix Enhances Detection of Endotoxin by MALDI-MS for Simultaneous Profiling of Pathogen, Host, and Vector Systems.

The discovery of novel pathogenic mechanisms engaged during bacterial infections requires the evolution of advanced techniques. Here, we evaluate the dual polarity matrix norharmane (NRM) to improve detection of bacterial lipid A (endotoxin), from host and vector tissues infected with Francisella novicida (Fn). We evaluated NRM for improved detection and characterization of a wide range of lipids in both positive and negative polarities, including lipid A and phospholipids across a range of matrix assisted laser desorption-ionization (MALDI)-coupled applications.