Search

Adequate micronutrient intake and status are global public health goals. Vitamin and mineral deficiencies are widespread and known to impair health and survival across the life stages. However, knowledge of molecular effects, metabolic pathways, biological responses to variation in micronutrient nutriture, and abilities to assess populations for micronutrient deficiencies and their pathology remain lacking. Rapidly evolving methodological capabilities in genomics, epigenomics, proteomics, and metabolomics offer unparalleled opportunities for the nutrition research community to link micronutrient exposure to cellular health; discover new, arguably essential micronutrients of microbial origin; and integrate methods of molecular biology, epidemiology, and intervention trials to develop novel approaches to assess and prevent micronutrient deficiencies in populations. In this review article, we offer new terminology to specify nutritional application of multiomic approaches and encourage collaboration across the basic to public health sciences to advance micronutrient deficiency prevention. [ABSTRACT FROM AUTHOR]

Urinary N 1 , N 12 -diacetylspermine (DAS) is a known biomarker for colorectal cancer (CRC). However, DAS levels in both healthy and CRC patients' urine samples are extremely low and often challenging to quantify. Complex and expensive methods do exist to detect DAS in urine, but simpler, less expensive methods to detect DAS are needed, especially in low resource settings. Here we describe a highly efficient, fast, precise, and inexpensive colorimetric assay to detect low levels of DAS in human urine samples. We used recombinant diacetylspermine oxidase (rDAS Ox), expressed and extracted from E. coli, to oxidize DAS, producing three products including hydrogen peroxide (H 2 O 2 ). The level of DAS present, which correlates with H 2 O 2 levels, was measured using horseradish peroxidase (HRP), which together with H 2 O 2 , oxidized Amplex™ Red to produce the pink-colored resorufin. The concentration of resorufin is directly proportional to H 2 O 2 (and DAS) levels. As urine contains metabolites which interfere with these oxidation reactions, we developed a simple two column-based protocol using ion exchange resins to remove these compounds and concentrate the DAS. With this novel cleaning and concentrating method, DAS was concentrated 15 times (confirmed by nuclear magnetic resonance (NMR) spectroscopy) and <1 μM DAS could be detected. Correlation graphs of urine samples spiked with known DAS concentrations versus assay-determined DAS concentrations had high coefficients of determination (R 2 ) for 0-10 μM DAS (0.94) and for 0-1 μM DAS (0.91), clearly demonstrating the excellent performance of the two-column protocol with the rDAS Ox reaction mixture. To the best of our knowledge, this is first reported colorimetric enzymatic assay that quantitates DAS in urine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Alzheimer's disease (AD) is a progressive neurological disease marked by the accumulation and deposition of misfolded amyloid beta or Abeta (Aβ) peptide. Two species of Aβ peptides are found in amyloid plaques, Aβ 1-40 and Aβ 1-42, with the latter being the more amyloidogenic of the two. Understanding how and why Aβ peptides misfold, oligomerize and form amyloid plaques requires a detailed understanding of their structure and dynamics. The poor solubility and strong aggregation tendencies of Aβ 1-42 has made the isolation and characterization of its different structural isoforms (monomer, dimer, oligomer, amyloid) exceedingly difficult. Furthermore, while synthetic Aβ 1-42 peptides (Aβ 42 syn) are readily available, the cost of isotopically labeled peptide is substantial, making their characterization by NMR spectroscopy cost prohibitive. Here we describe the design, cloning, high-level production, isotopic labeling and biophysical characterization of a modified (solubility-tagged) Aβ 1-42 variant that exhibits excellent water solubility and shares similar aggregation properties as wildtype Aβ 1-42 . Specifically, we attached six lysines (6K) to the C-terminus of native Aβ 1-42 to create a more soluble, monomeric form of Aβ 1-42 called Aβ 42 C6K. A gene for the Aβ 42 C6K was designed, synthesized and cloned into Escherichia coli (E. coli) and the peptide was expressed at milligram levels. The Aβ 42 C6K peptide was characterized using circular dichroism (CD), NMR, electron microscopy and thioflavin T fluorescence. Its ability to form stable monomers, oligomers and fibrils under different conditions was assessed. Our results indicate that Aβ 42 C6K stays monomeric at high concentrations (unlike Aβ 1-42 ) and can be induced to oligomerize and form fibrils like Aβ 1-42 . Our novel construct could be used to explore the structure and dynamics of Aβ 1-42 as well as the interaction of ligands with Aβ 1-42 via NMR., (Copyright © 2019 Elsevier Inc. All rights reserved.)