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Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Aspartate or aspartic acid is the precursor to several amino acids such as isoleucine, lysine, methionine, and threonine. It participates in gluconeogenesis and in the urea cycle. It is a neurotransmitter, but its activity is weaker than that of L-glutamate.
THE ANALYSIS OF ANIMAL CARCINOGENICITY EXPERIMENTS
Published in Richard G. Cornell, Statistical Methods for Cancer Studies, 2020
Richard G. Cornell, Robert A. Wolfe, William J. Butler
Much of the research throughout the development of aspartame was motivated by concern for its carcinogenic potential even though the ubiquity of the component amino acids, aspartic acid and phenylalanine, suggests that the likelihood of carcinogenicity is small. However, from among the many studies exploring carcinogenic potential by both in-vitro and in-vivo methods, one study suggested a possible association of aspartame with an increase in incidence of brain tumors in rats. Therefore brain tumors were of special interest in this illustration.
Single Amino Acids
Published in Luke R. Bucci, Nutrition Applied to Injury Rehabilitation and Sports Medicine, 2020
Another dietary dispensable amino acid — aspartate (aspartic acid) — has been studied in relation to fatigue in humans.248,249 Several studies from the 1950s found subjective improvements in fatigue, which were not replicated. Further studies found mixed results in terms of ergogenic effects during exercise in humans. The research seemed to support hypothetical mechanisms of action for aspartates: (1) transport of minerals to subcellular sites of action; (2) participant in tricarboxylic acid cycle (cellular energy); and (3) part of urea cycle (removal of ammonia). Thus, aspartate shares some mechanisms in common with arginine, and arginine aspartate has been used with clinical success in human wound healing and immune function preservation. However, no specific information on the effect of high doses of aspartates on animal or human connective tissue healing is available.
Restoring the biological activity of crizanlizumab at physiological conditions through a pH-dependent aspartic acid isomerization reaction
Published in mAbs, 2023
Fabian Bickel, François Griaud, Wolfram Kern, Frieder Kroener, Manuela Gritsch, Jérôme Dayer, Samuel Barteau, Blandine Denefeld, Chi-Ya Kao-Scharf, Manuel Lang, Izabela Slupska-Muanza, Carla Schmidt, Matthias Berg, Jürgen Sigg, Lina Boado, Dirk Chelius
Aspartic acid isomerization in the CDR can affect the target-binding behavior. For crizanlizumab, potency was decreased by the presence of increased succinimide levels. The impact of succinimide on the potency is also reported for other molecules17,18,20,35 and can be explained by a change in the binding affinity, potentially caused by the cyclization.20 The potency of crizanlizumab was recovered after 24 h at physiological temperature and pH conditions, due to the succinimide hydrolysis resulting in the formation of iso-aspartic acid-containing variants. This reveals that iso-aspartic acid does not lead to a decreased biological activity under physiologic conditions. It furthermore shows that the potency is comparable to the aspartic acid variant. The increased potency (above 100%) of the sample incubated at pH 7.4 compared to an unstressed crizanlizumab reference sample (used for the assay) with a defined potency of 100% can be explained by the presence of less succinimide in the pH 7.4 sample, and is not due to the iso-aspartic acid itself. This assumption is also supported by the potency for the AEX fractions main, AP1 and AP2. The potency obtained by CBA increases from main with 102% to 141% for AP2 (see Table 1). Since AEX fractions are mixtures, more succinimide in the main fraction is expected compared to AP1 or AP2, based on the separation behavior. Hence, the potency is increased with decreasing succinimide amounts from main to AP1 and to AP2.
Labour analgesia; Molecular pathway and the role of nanocarriers: a systematic review
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Leila Kafshdooz, Houman Kahroba, Tayebeh Kafshdooz, Hojjat Pourfathi
A118G variant in exon 1 is the most common SNP of the OPRM1. This polymorphism exchanges asparagine to aspartic acid at N-glycosylation site [52]. Aspartic acid may increase the binding affinity of b-endorphin [53] and influences the response to epidural opioid analgesia during labour [54]. Experiments on the effect of A118G variant of OPRM1 carried out by Landau et al. on Swiss nulliparous women [55]. Higher dose of fentanyl is required for A118 homozygotes. In the classical approach, the proper dose of drugs is required to improve clinical outcomes [56]. Wong et al. reported the correlation of the duration of intrathecal fentanyl analgesia and A118G variant of OPRM1 in the first stage of labour [57]. Camorcia et al. evaluated the response to epidural sufentanil and showed that A118 homozygotes women required higher doses [58]. Researchers did not confirm any significant correlation between A118G variant of OPRM1 and cervical dilation on arrival at the delivery unit or use of any type of analgesia (epidural or second-line analgesia) during labour [54]. Therefore, it is biologically plausible that genetic variations of OPRM1 A118G polymorphism may modulate an individual’s response to epidural analgesia with fentanyl during labour [58].
The possible protective role of pimpinella anisum oil versus selenium on aspartame induced changes in rat cerebellar cortex: histological, immunohistochemical and electron microscopic study
Published in Ultrastructural Pathology, 2022
Amira I. Shrief, Ahmed A.M Abdel-Hamid, Am Moustafa, E. El-Mohandes
Mechanism of toxicity of aspartame is related to its metabolites. Each of them is toxic and affect different body tissues including central nervous system. After oral ingestion, Aspartame is metabolized in gastrointestinal tract to 40% aspartic acid, 50% phenylalanine, and 10% methanol.3 Aspartic acid is excitatory neurotransmitter; it is excitotoxin, which contribute to free radical damage in the brain.5 Phenylalanine crosses blood brain barrier and acts as precursor of catecholamine in the brain leading to alternation in neurotransmitter levels.6 Methanol is converted in liver to formaldehyde and then formate, which is neurotoxin and carcinogen.7