Systems biochemistry to "deorphanize" human mitochondrial proteome.

Rensvold, Shishkova, et al. (2022) apply an integrated systems biology approach spanning proteomics, lipidomics, and metabolomics to a collection of CRISPR knockout cells targeting 116 distinct human mitochondrial proteins, revealing new mitochondrial biology and guiding orphan disease diagnosis.

Phosphorus deficiencies invoke optimal allocation of exoenzymes by ectomycorrhizas.

Ectomycorrhizal (EM) fungi can acquire phosphorus (P) through the production of extracellular hydrolytic enzymes (exoenzymes), but it is unclear as to the manner and extent native EM fungal communities respond to declining soil P availability. We examined the activity of six exoenzymes (xylosidase, N-acetyl glucosaminidase, β-glucosidase, acid phosphomonoesterase, acid phosphodiesterase [APD], laccase) from EM roots of Pseudotsuga menzesii across a soil podzolization gradient of coastal British Columbia. We found that APD activity increased fourfold in a curvilinear association with declining inorganic P.

Exploring feature selection of St John's wort grown under different light spectra using H-NMR spectroscopy.

Introduction: Nuclear magnetic resonance (NMR) spectroscopy combined with multivariate statistical analysis can provide tools to help detect differences in plant chemistry when grown under varying conditions. Hypericum perforatum, or Saint John's wort, plants are a suitable model to explore methods of discrimination between early stage plants grown in different conditions.

Objectives: The purpose of this work was to develop a method for identifying differences in chemical profiles between young Hypericum perforatum plants grown under different lighting conditions.

Asymmetric Anion-π Catalysis on Perylenediimides.

Anion-π catalysis, that is the stabilization of anionic transition states on π-acidic aromatic surfaces, has so far been developed with naphthalenediimides (NDIs). This report introduces perylenediimides (PDIs) to anion-π catalysis. The quadrupole moment of PDIs (+23.

Core-Substituted Naphthalenediimides: LUMO Levels Revisited, in Comparison with Preylenediimides with Sulfur Redox Switches in the Core.

Core-substituted naphthalenediimides (NDIs) attract increasing attention to bind, transport, and transform electrons, anions, anionic intermediates, and anionic transition states, and to shine as most colorful rainbow fluorophores. The energy level of their lowest unoccupied molecular orbital (LUMO) is decisive for many of these applications. Here, differential pulse voltammetry (DPV) measurements for a consistent series of NDIs are reported to extract exact LUMO levels under identical conditions.

Enolate Stabilization by Anion-π Interactions: Deuterium Exchange in Malonate Dilactones on π-Acidic Surfaces.

Of central importance in chemistry and biology, enolate chemistry is an attractive topic to elaborate on possible contributions of anion-π interactions to catalysis. To demonstrate the existence of such contributions, experimental evidence for the stabilization of not only anions but also anionic intermediates and transition states on π-acidic aromatic surfaces is decisive. To tackle this challenge for enolate chemistry with maximal precision and minimal uncertainty, malonate dilactones are covalently positioned on the π-acidic surface of naphthalenediimides (NDIs).

Role of histidine 225 in adenosylcobalamin-dependent ornithine 4,5-aminomutase.

Pyridoxal 5'-phosphate (PLP), in the active site of ornithine 4,5-aminomutase (OAM), forms a Schiff base with N(δ) of the d-ornithine side chain and facilitates interconversion of the amino acid to (2R, 4S) 2,4-diaminopentanoic acid via a radical-based mechanism. The crystal structure of OAM reveals that His225 is within hydrogen bond distance to the PLP phenolic oxygen, and may influence the pK(a) of the Schiff base during radical rearrangement. To evaluate the role of His225 in radical stabilization and catalysis, the residue was substituted with a glutamine and alanine.