Biology subjects

Bailey, H.

Publications and source records attributed to Bailey, H..

3 recordsLinked to original sources

bioRxiv2022

Lead (Pb) impairs thyroid hormone mediated changes in brain development and body length in Xenopus laevis tadpoles

Lead (Pb) poisoning during early development is associated with behavioral and cognitive deficits, but the specific mechanisms by which Pb impairs brain development are not fully understood. One potential mechanism is that Pb poisoning may impair thyroid hormone (TH)- mediated changes in brain development To address this issue, we performed experiments to assess the effects of Pb poisoning on (TH) -dependent changes in cellular and molecular mechanisms in the developing Xenopus laevis tadpole brain. We treated stage 48 tadpoles to combinations of 1000 ppb Pb bath for seven days and added one of three different concentrations of thyroxine (T4) for the final two days of treatment. We found that lead exposure decreased body length, including in T4-treated tadpoles. We also performed immuno-staining for proliferative marker pH3 and found that Pb disrupts T4-induced increases in neuronal proliferation. Finally, we used syGlass VR data visualization software to measure volume of the forebrain, midbrain, and hindbrain in 3D and found that Pb exposure impaired T4-mediated changes in brain volume. Last, we found that Pb poisoning reduced the T4-mediated increase in proliferating cell nuclear antigen (PCNA), a TH-sensitive gene. These results illustrate that Pb poisoning impairs some TH-dependent changes in the developing brain.

pharmacology and toxicology↗

bioRxiv2021

Shiitake mycelium fermentation improves digestibility, nutritional value, flavor and functionality of plant proteins

Plant proteins can serve as inexpensive and environmentally friendly meat-replacements. However, poor taste characteristics and relatively low nutritional value prevent their full acceptance as meat substitutes. Fermentation of food has been historically used to improve the quality of foods. In this work we describe the improvement in digestibility, nutritional value, physical properties, and organoleptic characteristics, of a pea and rice protein concentrate blend through fermentation with shiitake mushroom mycelium. Ileal digestibility pig studies show increases in the DIAAS for the shiitake fermented pea and rice protein blend turning the blend into an "excellent source" of protein for humans. The fermentation also increases the solubility of the protein blend and reduces the content of the antinutrient compounds phytates and protease inhibitor. Mass spectrometry and sensory analyses of fermented protein blend indicates that fermentation leads to a reduction in off-note compounds substantially improving its organoleptic performance.

bioengineering↗

bioRxiv2020

Naturally occurring cobalamin (B12) analogs can function as cofactors for human methylmalonyl-CoA mutase

Cobalamin, commonly known as vitamin B12, is an essential micronutrient for humans because of its role as an enzyme cofactor. Cobalamin is one of over a dozen structurally related compounds - cobamides - that are found in food and are produced by microorganisms in the human gut. Very little is known about how different cobamides affect B12-dependent metabolism in human cells. Here, we test in vitro how diverse cobamide cofactors affect the function of methylmalonyl-CoA mutase (MMUT), one of two cobalamin-dependent enzymes in humans. We find that, although cobalamin is the most effective cofactor for MMUT, multiple cobamides support MMUT function with differences in binding affinity (Kd), binding kinetics (kon), and concentration dependence during catalysis (KM, app). Additionally, we find that six disease-associated MMUT variants that cause cobalamin-responsive impairments in enzymatic activity also respond to other cobamides, with the extent of catalytic rescue dependent on the identity of the cobamide. Our studies challenge the exclusive focus on cobalamin in the context of human physiology, indicate that diverse cobamides can support the function of a human enzyme, and suggest future directions that will improve our understanding of the roles of different cobamides in human biology.

biochemistry↗