-
Wellcome Open Research 2023Protein analysis using matrix-assisted laser desorption/ionisation time-of-flight mass-spectrometry (MALDI-TOF MS) represents a promising tool for entomological...
BACKGROUND
Protein analysis using matrix-assisted laser desorption/ionisation time-of-flight mass-spectrometry (MALDI-TOF MS) represents a promising tool for entomological surveillance. In this study we tested the discriminative power of this tool for measuring species and blood meal source of main Afrotropical malaria vectors on the Kenyan coast.
METHODS
Mosquito collections were conducted along the coastal region of Kenya. MALDI-TOF MS spectra were obtained from each individual mosquito's cephalothorax as well as the abdomens of blood-engorged mosquitoes. The same mosquitoes were also processed using gold standard tests: polymerase chain reaction (PCR) for species identification and enzyme linked immunosorbent assay (ELISA) for blood meal source identification.
RESULTS
Of the 2,332 mosquitoes subjected to MALDI-TOF MS, 85% (1,971/2,332) were considered for database creation and validation. There was an overall accuracy of 97.5% in the identification of members of the ( , 100%; , 91.9%; , 97.5%; and , 90.2%) and ( , 94.2%; , 99.4%; and , 94.1%) complexes. Furthermore, MALDI-TOF MS also provided accurate (94.5% accuracy) identification of blood host sources across all mosquito species.
CONCLUSIONS
This study provides further evidence of the discriminative power of MALDI-TOF MS to identify sibling species and blood meal source of Afrotropical malaria vectors, further supporting its utility in entomological surveillance. The low cost per sample (<0.2USD) and high throughput nature of the method represents a cost-effective alternative to molecular methods and could enable programs to increase the number of samples analysed and therefore improve the data generated from surveillance activities.
PubMed: 38957296
DOI: 10.12688/wellcomeopenres.18982.2 -
Current Research in Food Science 2024Variations in volatile flavor components in pigmented onion bulbs (purple, white, and yellow) before and after cooking were characterized by headspace gas...
Variations in volatile flavor components in pigmented onion bulbs (purple, white, and yellow) before and after cooking were characterized by headspace gas chromatography-ion migration spectrometry (HS-GC-IMS) to investigate their odor traits. Results showed that 39 and 45 volatile flavor compounds were identified from pigmented onion bulbs before and after cooking via the HS-GC-IMS fingerprinting, respectively. Sulfurs (accounting for 50.65%-63.42%), aldehydes (13.36%-22.11%), and alcohols (11.32%-17.94%) ranked the top three prevailing compound categories in all pigmented onions (both raw and cooked). Compared to the raw colored onion bulbs, the relative proportion of sulfurs in cooked onions decreased, whereas the relative proportion of alcohols, esters, pyrazines, and furans increased. Two reliable prediction models were established through orthogonal partial least squares-discriminant analysis (OPLS-DA), and 8 and 22 distinctive odor compounds were sieved out by variable importance in projection (VIP>1.0) as volatile labels, respectively. Both principal component analysis (PCA) and clustering heatmap exhibited favorable distinguishing effects for various pigmented onion bulbs before and after cooking. These results might offer insights into understanding the odor characteristics of different pigmented onions.
PubMed: 38957287
DOI: 10.1016/j.crfs.2024.100781 -
Ophthalmic Genetics Jul 2024BCL6 co-repressor () gene variants are involved in oculofaciocardiodental (OFCD) syndrome, acute myeloid leukaemia, renal tumours, and photoreceptor degenerative...
BACKGROUND
BCL6 co-repressor () gene variants are involved in oculofaciocardiodental (OFCD) syndrome, acute myeloid leukaemia, renal tumours, and photoreceptor degenerative diseases. Here, we describe a British family with a pathogenic heterozygous variant in the gene causing congenital nuclear cataract.
METHODS
Whole-exome sequencing was conducted on an individual affected by X-linked dominant congenital cataract in a three-generation family to establish the underlying genetic basis. Bioinformatics analysis confirmed the variants with damaging pathogenicity scores.
RESULTS
A novel likely pathogenic frameshift variant NM_001123385.1: c.3621del; p.Lys1207AsnfsTer31, was identified and found to co-segregate with the disease in this family.
CONCLUSIONS
This is apparently the first report of a variant in causing X-linked dominant congenital cataract which is potentially isolated or presenting with a remarkably mild systemic phenotype. Our findings extend the genetic basis for congenital cataract and add to the phenotypic spectrum of variants.
PubMed: 38957147
DOI: 10.1080/13816810.2024.2373248 -
Journal of the American Chemical Society Jul 2024The binding affinity determination of protein-ligand complexes is a cornerstone of drug design. State-of-the-art techniques are limited by lengthy and expensive...
The binding affinity determination of protein-ligand complexes is a cornerstone of drug design. State-of-the-art techniques are limited by lengthy and expensive processes. Building upon our recently introduced novel screening method utilizing photochemically induced dynamic nuclear polarization (photo-CIDNP) NMR, we provide the methodological framework to determine binding affinities within 5-15 min using 0.1 mg of protein. The accuracy of our method is demonstrated for the affinity constants of peptides binding to a PDZ domain and fragment ligands binding to the protein PIN1. The method can also be extended to measure the affinity of nonphoto-CIDNP-polarizable ligands in competition binding experiments. Finally, we demonstrate a strong correlation between the ligand-reduced signals in photo-CIDNP-based NMR fragment screening and the well-established saturation transfer difference (STD) NMR. Thus, our methodology measures protein-ligand affinities in the micro- to millimolar range in only a few minutes and informs on the binding epitope in a single-scan experiment, opening new avenues for early stage drug discovery approaches.
Topics: Ligands; Nuclear Magnetic Resonance, Biomolecular; Protein Binding; Photochemical Processes; NIMA-Interacting Peptidylprolyl Isomerase; Proteins; Peptides; Magnetic Resonance Spectroscopy; Models, Molecular; PDZ Domains
PubMed: 38957136
DOI: 10.1021/jacs.4c04000 -
Journal of Food Science Jul 2024Extraction of starch from waste is also an effective way to recover resources and provide new sources of starch. In this study, starch was isolated from white kidney... (Comparative Study)
Comparative Study
Extraction of starch from waste is also an effective way to recover resources and provide new sources of starch. In this study, starch was isolated from white kidney bean residue, chickpea residue, and tiger nut meal after protein or oil extraction, and the morphology of starch particles was observed to determine their physicochemical properties and in vitro digestibility. All these isolated starches had unique properties, among which white kidney bean starch (KBS) had a high amylose content (43.48%), and its structure was better ordered. Scanning electron microscopy revealed distinct granular morphologies for the three starches. KBS and chickpea starch (CHS) were medium-granular starches, whereas tiger nut starch was a small granular starch. Fourier transform infrared spectroscopy analysis confirmed the absence of significant differences in functional groups and chemical bonds among the three starch molecules. In vitro digestibility studies showed that CHS is more resistant to enzymatic degradation. Overall, these results will facilitate the development of products based on the separation of nonconventional starches from waste.
Topics: Starch; Digestion; Cicer; Spectroscopy, Fourier Transform Infrared; Amylose; Phaseolus; Microscopy, Electron, Scanning
PubMed: 38957110
DOI: 10.1111/1750-3841.17171 -
Journal of Food Science Jul 2024The elucidation of the interaction mechanism between phospholipids and milk proteins within emulsions is pivotal for comprehending the properties of infant formula fat...
The elucidation of the interaction mechanism between phospholipids and milk proteins within emulsions is pivotal for comprehending the properties of infant formula fat globules. In this study, multispectral methods and molecular docking were employed to explore the relationship between phosphatidylcholine (PC) and whey protein isolate (WPI). Observations indicate that the binding constant, alongside thermodynamic parameters, diminishes as temperature ascends, hinting at a predominantly static quenching mechanism. Predominantly, van der Waals forces and hydrogen bonds constitute the core interactions between WPI and PC. This assertion is further substantiated by Fourier transform infrared spectroscopy, which verifies PC's influence on WPI's secondary structure. A detailed assessment of thermodynamic parameters coupled with molecular docking reveals that PC predominantly adheres to specific sites within α-lactalbumin, β-lactoglobulin, and bovine serum albumin, propelled by a synergy of hydrophobic interactions, hydrogen bonding, and van der Waals forces, with binding energies noted at -5.59, -6.71, and -7.85 kcal/mol, respectively. An increment in PC concentration is observed to amplify the emulsification properties of WPI whilst concurrently diminishing the zeta potential. This study establishes a theoretical foundation for applying the PC-WPI interaction mechanism in food.
Topics: Whey Proteins; Phosphatidylcholines; Molecular Docking Simulation; Spectroscopy, Fourier Transform Infrared; Hydrophobic and Hydrophilic Interactions; Thermodynamics; Hydrogen Bonding; Lactoglobulins; Emulsions; Lactalbumin; Serum Albumin, Bovine; Infant Formula
PubMed: 38957103
DOI: 10.1111/1750-3841.17175 -
Journal of Food Science Jul 2024The improper storage of seeds can potentially compromise agricultural productivity, leading to reduced crop yields. Therefore, assessing seed viability before sowing is...
Rapid and nondestructive watermelon (Citrullus lanatus) seed viability detection based on visible near-infrared hyperspectral imaging technology and machine learning algorithms.
The improper storage of seeds can potentially compromise agricultural productivity, leading to reduced crop yields. Therefore, assessing seed viability before sowing is of paramount importance. Although numerous techniques exist for evaluating seed conditions, this research leveraged hyperspectral imaging (HSI) technology as an innovative, rapid, clean, and precise nondestructive testing method. The study aimed to determine the most effective classification model for watermelon seeds. Initially, purchased watermelon seeds were segregated into two groups: One underwent sterilization in a dehydrator machine at 40°C for 36 h, whereas the other batch was stored under favorable conditions. Watermelon seeds' spectral images were captured using an HSI with a charge-coupled device camera ranging from 400 to 1000 nm, and the segmented regions of all samples were measured. Preprocessing techniques and wavelength selection methods were applied to manage spectral data workload, followed by the implementation of a support vector machine (SVM) model. The initial hybrid-SVM model achieved a predictive accuracy rate of 100%, with a test set accuracy of 92.33%. Subsequently, an artificial bee colony (ABC) optimization was introduced to enhance model precision. The results indicated that, with kernel parameters (c, g) set at 13.17 and 0.01, respectively, and a runtime of 4.19328 s, the training and evaluation of the dataset achieved an accuracy rate of 100%. Hence, it was practical to utilize HSI technology combined with the PCA-ABC-SVM model to detect different watermelon seeds. As a result, these findings introduce a novel technique for accurately forecasting seed viability, intended for use in agricultural industrial multispectral imaging. PRACTICAL APPLICATION: The traditional methods for determining the condition of seeds primarily emphasize aesthetics, rely on subjective assessment, are time-consuming, and require a lot of labor. On the other hand, HSI technology as green technology was employed to alleviate the aforementioned problems. This work significantly contributes to the field of industrial multispectral imaging by enhancing the capacity to discern various types of seeds and agricultural crop products.
Topics: Citrullus; Seeds; Hyperspectral Imaging; Machine Learning; Spectroscopy, Near-Infrared; Support Vector Machine; Algorithms
PubMed: 38957090
DOI: 10.1111/1750-3841.17151 -
Phytochemical Analysis : PCA Jul 2024Sophora flavescens Aiton (Fabaceae), a ubiquitous plant species in Asia, contains a wide range of pharmacologically active compounds, such as flavonoids, with potential...
Quaternity method for integrated screening, separation, extraction optimization, and bioactivity evaluation of acetylcholinesterase inhibitors from Sophora flavescens Aiton.
INTRODUCTION
Sophora flavescens Aiton (Fabaceae), a ubiquitous plant species in Asia, contains a wide range of pharmacologically active compounds, such as flavonoids, with potential anti-Alzheimer's disease (anti-AD) effects.
OBJECTIVES
The objective of the study is to develop a quaternity method for the screening, isolation, extraction optimization, and activity evaluation of acetylcholinesterase (AChE)-inhibiting compounds from S. flavescens to realize high-throughput screening of active substances in traditional Chinese medicine and to provide experimental data for the development of anti-AD drugs.
METHODS
With AChE as the target molecule, affinity ultrafiltration and liquid chromatography-mass spectrometry were applied to screen for potential inhibitors of the enzyme in S. flavescens. Orthogonal array experiments combined with the multi-objective Non-Dominated Sorting Genetic Algorithm III was used for the first time to optimize the process for extracting the active substances. Enzyme inhibition kinetics and molecular docking studies were performed to verify the potential anti-AD effects of the active compounds.
RESULTS
Five AChE-inhibiting compounds were identified: kushenol I, kurarinone, sophoraflavanone G, isokurarinone, and kushenol E. These were successfully separated at purities of 72.88%, 98.55%, 96.86%, 96.74%, and 95.84%, respectively, using the n-hexane/ethyl acetate/methanol/water (4.0/5.0/4.0/5.0, v/v/v/v), n-hexane/ethyl acetate/methanol/water (5.0/5.0/6.0/4.0, v/v/v/v), and n-hexane/ethyl acetate/methanol/water (4.9/5.1/5.7/4.3, v/v/v/v) mobile phase systems. Enzyme inhibition kinetics revealed that kushenol E had the best inhibitory effect.
CONCLUSION
This study elucidates the mechanism of action of five active AChE inhibitors in S. flavescens and provides a theoretical basis for the screening and development of anti-AD and other therapeutic drugs.
PubMed: 38957046
DOI: 10.1002/pca.3415 -
Journal of the American Society For... Jul 2024Native mass spectrometry (MS) analysis of protein complexes is highly susceptible to matrix effect, and addressing this predicament using buffer exchange is a common...
Probing High-order Protein Complexes Using Native Mass Spectrometry and Hydrogen/Deuterium Exchange Mass Spectrometry: A Case Study Using Fresh and Commercial Hemoglobin Samples.
Native mass spectrometry (MS) analysis of protein complexes is highly susceptible to matrix effect, and addressing this predicament using buffer exchange is a common approach. Nevertheless, optimization of the buffer exchange protocol is not trivial. With the use of hemoglobin (Hb) as the model entity, it was discovered that the native mass spectrum of protein assembly is highly dependent on the buffer-exchange protocol. Given the dependence of native MS on the purification protocol, this work attempts to use hydrogen/deuterium exchange mass spectrometry (HDX-MS) for comparative studies of hemoglobin complexes in untreated fresh and commercial samples. The information obtained from the HDX study was found to correlate well with the native mass spectrometry analysis of the properly buffer-exchanged Hb samples. Both native MS and HDX-MS showed that the fresh Hb sample has retained the expected tetrameric structure, whereas the commercial Hb has largely been denatured to the dimeric form. These findings prove the complementarity of native MS and HDX-MS in the analysis of high-order protein complexes and stress the necessity to validate the integrity of the high-order structures of the proteins prior to the use of the protein samples for other biomedical studies.
PubMed: 38957002
DOI: 10.1021/jasms.4c00201 -
Drug Testing and Analysis Jul 2024ELISA assays are commonly used for drug screening by racing laboratories but are known to suffer from limited specificity. Inaccurate ELISA screening results are...
ELISA assays are commonly used for drug screening by racing laboratories but are known to suffer from limited specificity. Inaccurate ELISA screening results are typically produced by non-specific antibody interactions or by the retention of chromogenic material in the sample well due to sample degradation. While confirmation of drug positives can be achieved by mass spectrometry, the follow-up of inaccurate ELISA screening results represents an unnecessary cost in staff time and reagents. This is particularly true in the case of rhEPO screening using sandwich ELISA assays, where the confirmation method requires up to 3 days to perform. While most racing laboratories purchase commercial ELISA kits, these products can be customised to provide increased specificity for enhanced screening of positive samples. The specificity of commercial sandwich ELISA kits can be improved by a variety of mechanisms including the addition of competing analyte specific antibodies, substitution of capture antibodies or by performing ELISA analysis with and without capture antibodies. Non-specific signals in difficult matrices such as canine urine can also be reduced by the addition of BSA solutions to the ELISA plate prior to the addition of samples.
PubMed: 38956951
DOI: 10.1002/dta.3763