V. A. Ricigliano, C. Dong, L.T. Richardson, F. Donnarumma, S.T. Williams, T. Solouki, K.K. Murray, Honey Bee Proteome Responses to Plant and Cyanobacteria (blue-green algae) Diets, ACS Food Science & Technology, 1 (2021) 17-26. 10.1021/acsfoodscitech.0c00001
Malnutrition is an increasing threat to honey bees that can be mitigated by feeding artificial pollen substitute diets; however, little is known about the molecular mechanisms underlying their impact on bee health. Here, we examined proteomic responses to natural and artificial diets in the honey bee fat body, a tissue with central nutrient storage and metabolic functions. Bees were fed protein diets of natural pollen, a commercial plant-based diet used by beekeepers that does not contain pollen (Ultra Bee), and two novel cyanobacteria diets comprising dried or fresh laboratory-grown Arthrospira platensis (commonly, spirulina). Relative to a protein-free control group, diet consumption elicited broad upregulation of metabolic processes associated with amino acids, carbohydrates, and lipids. Plant and cyanobacteria diets led to equivalent dietary protein assimilation and a marked overlap in proteome expression patterns, indicative of comparable nutritive and metabolic impacts. This was corroborated by equivalent titers of the storage lipoprotein vitellogenin and nutritionally-regulated stress response proteins (superoxide dismutase, glutathione S-transferase 1, catalase, and heat shock protein 90). The tested diets recapitulated the proteomic effects of a natural pollen diet and support stress resistance via improved nutritional status. Our results provide new insights into the impact of artificial feed on honey bees and highlight the potential of cyanobacterial biomass as a sustainable nutrition source for improving bee health.
A. Chaichi, S.M.A. Hasan, N. Mehta, F. Donnarumma, P. Ebenezer, K.K. Murray, J. Francis, M.R. Gartia, Label-free lipidome study of paraventricular thalamic nucleus (PVT) of rat brain with post-traumatic stress injury by Raman imaging, Analyst, 146 (2021) 170-183.
Post-traumatic stress disorder (PTSD) is a widespread psychiatric injury that develops serious life-threatening symptoms like substance abuse, severe depression, cognitive impairments, and persistent anxiety. However, the mechanisms of post-traumatic stress injury in brain are poorly understood due to the lack of practical methods to reveal biochemical alterations in various brain regions affected by this type of injury. Here, we introduce a novel method that provides quantitative results from Raman maps in the paraventricular nucleus of the thalamus (PVT) region. By means of this approach, we have shown a lipidome comparison in PVT regions of control and PTSD rat brains. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was also employed for validation of the Raman results. Lipid alterations can reveal invaluable information regarding the PTSD mechanisms in affected regions of brain. We have showed that the concentration of cholesterol, cholesteryl palmitate, phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, sphingomyelin, ganglioside, glyceryl tripalmitate and sulfatide changes in the PVT region of PTSD compared to control rats. A higher concentration of cholesterol suggests a higher level of corticosterone in the brain. Moreover, concentration changes of phospholipids and sphingolipids suggest the alteration of phospholipase A2 (PLA2) which is associated with inflammatory processes in the brain. Our results have broadened the understanding of biomolecular mechanisms for PTSD in the PVT region of the brain. This is the first report regarding the application of Raman spectroscopy for PTSD studies. This method has a wide spectrum of applications and can be applied to various other brain related disorders or other regions of the brain.
F. Cao, F. Donnarumma, K.K. Murray, Wavelength-Dependent Tip-Enhanced Laser Ablation of Organic Dyes, Journal of Physical Chemistry C, 124 (2020) 1918-1922; doi: 10.1021/acs.jpcc.9b08081
The wavelength dependence of atomic force microscope apertureless tip-enhanced laser ablation was studied using a series of organic dyes to assess the effect of surface optical absorption. An optical parametric oscillator laser with a tunable wavelength range of 410-2100 nm was used to irradiate a gold-coated atomic force microscope tip which was held 15 nm above the surface of a dye thin film vibrating in tapping mode to generate tip-enhanced laser ablation. Crater formation was investigated for rhodamine B, methylene blue, and IR 797 dye thin films which have absorption maxima near 550, 650, and 700 nm, respectively. Crater formation was not observed for wavelengths greater than 700 nm for any of the dyes. Below 700 nm, the crater size was greatest near 500 nm for all dyes and decreased from 500 to 700 nm, and no ablation was observed at longer wavelengths. The crater size did not correlate with the solution or thin film optical absorption of the dyes. The mechanism for tip-enhanced laser ablation is postulated to be either ballistic ejection of gold atoms or direct heat transfer from the tip to the surface.
B. Banstola, K.K. Murray, Sublimation Electrification of Organic Compounds, J. Am. Soc. Mass. Spectrom., 31 (2020) 888-893; doi: 10.1021/jasms.9b00124.
The electrification of crystalline deposits of organic compounds under high vacuum was measured and quantified. A group of compounds that produce multiply charged ions by matrix-assisted ionization were deposited on a metal plate, and the current was amplified and recorded; the total charge was obtained by integration of the current. Signals of several hundred picoamperes were obtained within 10 s of the application of high vacuum and persisted for several minutes as the compounds sublimed. The magnitude and sign of the charge were matrix dependent and were affected by the presence of organic or mineral acid in the crystalline deposit, as well as by the application of an electric field. The observations are interpreted as surface electrification caused by the emission of small charged matrix particles during sublimation, with ionic charge carriers comprising protons and hydroxide ions.
K. Wang, F. Donnarumma, M.E. Pettit, C.W. Szot, T. Solouki, K.K. Murray, MALDI imaging directed laser ablation tissue microsampling for data independent acquisition proteomics, J. Mass Spectrom., 55 (2020) e4475; doi: 10.1002/jms.4475
A multimodal workflow for mass spectrometry imaging was developed that combines MALDI imaging with protein identification and quantification by liquid chromatography tandem mass spectrometry (LC-MS/MS). Thin tissue sections were analyzed by MALDI imaging, and the regions of interest (ROI) were identified using a smoothing and edge detection procedure. A midinfrared laser at 3-μm wavelength was used to remove the ROI from the brain tissue section after MALDI mass spectrometry imaging (MALDI MSI). The captured material was processed using a single-pot solid-phase-enhanced sample preparation (SP3) method and analyzed by LC-MS/MS using ion mobility (IM) enhanced data independent acquisition (DIA) to identify and quantify proteins; more than 600 proteins were identified. Using a modified database that included isoform and the post-translational modifications chain, loss of the initial methionine, and acetylation, 14 MALDI MSI peaks were identified. Comparison of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the identified proteins was achieved through an evolutionary relationships classification system.
Photooxidation of peptides and proteins by pulsed ultraviolet laser irradiation of an electrospray in the ion source of a mass spectrometer was demonstrated. A 193-nm excimer laser at 1.5-mJ pulse energy was focused with a cylindrical lens at the exit of a nanoelectrospray capillary and ions were sampled into a quadrupole time-of-flight mass spectrometer. A solution containing a peptide or protein and hydrogen peroxide was infused into the spray at a flow rate of 1 μL/min using a syringe pump. The laser creates OH radicals directly in the spray which modify biomolecules within the spray droplet. These results indicate that photochemical oxidation of proteins can be initiated directly within electrospray droplets and detected by mass spectrometry.
B. Banstola, K.K. Murray, “A Nanoparticle Co-matrix for Multiple Charging in MALDI Imaging of Tissue,” Rapid Commun. Mass Spectrom.16 (2019) 12. doi:10.1002/rcm.8424.
Abstract Rationale: A two‐component matrix of 2‐nitrophloroglucinol (2‐NPG) and silica nanoparticles was used for matrix‐assisted laser desorption ionization (MALDI) mass spectrometry imaging of high‐charge‐state biomolecules in tissue. Potential advantages include increased effective mass range and efficiency of fragmentation. Methods: A mixture of 2‐NPG matrix and silica nanoparticles was applied to cyrosectioned 10 μm thick mouse brain tissue. The mixture was pipetted onto the tissue for profiling and sprayed for tissue imaging. MALDI images were obtained under high vacuum in a commercial time‐of‐flight mass spectrometer. Results: The combined 2‐NPG and nanoparticle matrix produced highly charged ions from tissue with high‐vacuum MALDI. Nanoparticles of 20, 70, 400, and 1000 nm in diameter were tested, the 20 nm particles producing the highest charge states. Images of mouse brain tissue obtained from highly charged ions show similar spatial localization. Conclusions: The combined 2‐NPG and nanoparticle matrix produces highly charged ions from tissue through a mechanism that may rely on the high surface area of the particles which can dry the tissue, and their ability to bind analyte molecules thereby assisting in crystal formation and production of multiply charged ions on laser irradiation.
I. Pereira, B. Banstola, K. Wang, F. Donnarumma, B.G. Vaz, K.K. Murray, Matrix-Assisted Laser Desorption Ionization Imaging and Laser Ablation Sampling for Analysis of Fungicide Distribution in Apples, Anal. Chem.91 (2019) 6051–6056. doi:10.1021/acs.analchem.9b00566.
ABSTRACT: A combination of matrix-assisted laser desorption ionization (MALDI) imaging and infrared (IR) laser ablation sampling with offline electrospray ionization mass spectrometry (ESI-MS) was used to determine the distribution of the fungicide imazalil in apples. MALDI images were used to determine the penetration depth of imazalil up to 7 days after its application. IR laser ablation sampling and ESI-MS were used to quantify the rate of penetration of the fungicide, which was determined to be approximately 1 mm per day. Imazalil concentration decreased in the apple skin over the course of the experiment, and after 7 days the fungicide was detected at 0.015 ppm 6 mm inside the apple. Approximately 60% of the pesticide remained in the skin after 7 days. This work demonstrates the utility of MALDI imaging for spatial localization of fungicide in fruit in combination with IR laser ablation and ESI-MS for quantitative analysis.