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Triticum Aestivum L.): Effects on the Distribution of Protein Sub-Fractions, Amino Acids, and Starch Characteristics
Published in Megh R. Goyal, Susmitha S. Nambuthiri, Richard Koech, Technological Interventions in Management of Irrigated Agriculture, 2018
Divya Jain, Bavita Asthir, Deepak Kumar Verma
GPT maintains a nitrogen–carbon balance through the interaction between AlaAT and pyruvate (Fig. 10.2). The rapid decay of GPT is an important feature of senescence of leaves in dark. GPT is an important regulatory enzyme. It is logical that its activity may be affected more than that of GOT. Since the activity of transaminases is stimulated under conditions that are deleterious to protein synthesis, it was postulated that these enzymes may be acting in the direction of deamination to provide amino acids, especially glutamic acid or aspartic acid for the common N-pool. In addition, all NH4+ assimilation enzyme activities were higher in roots than in shoots, suggesting that their main role was photorespiration, which constitutes the main source of inorganic-N in the leaves. On the other hand, it also indicated that amino acids are first transaminated in roots, then transformed into other amino acids, and finally synthesized into proteins after transport into shoots.99 Mo et al.113 showed that NH4 at high concentrations significantly increased the GPT activity of roots.
Biocatalysts: The Different Classes and Applications for Synthesis of APIs
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Transaminases (or aminotransferases) are enzymes transferring an amino group (EC 2.6.1.-). In the recent past, the use of PLP-dependent ω-transaminases (ω-TA; meanwhile (R)- and (S)-selective ω-TAs are known) for the synthesis of optically pure amines gained increasing interest in connection with the synthesis of active pharmaceutical ingredients (for reviews see, e.g., Fuchs et al., 2015; Simon et al., 2014). ω-TAs catalyze the reversible amination/deamination of suited substrates to yield optically pure amines either by kinetic resolution (one amine enantiomer is converted into a ketone whereas the desired amine enantiomer is left behind) or by asymmetric synthesis starting from a prochiral ketone. In these cases, the amine donor is l-alanine that is converted to pyruvate. In order to shift the equilibrium to the product side, the keto acid is converted to lactate in presence of lactate dehydrogenase; pyruvate decarboxylase has also been used for this purpose. Alternatively pyruvate may be recycled to alanine in presence of a alanine dehydrogenase. Very promising is the recently described use of o-xylylenediamine as a low-cost non-chiral amine donor (Green et al., 2014); in addition, spontaneous polymerization of the aromaticisoindoleformed during the course of the reaction yields intensively colored derivatives which may serve as a high-throughput screening platform to identify ω-TA activities. These enzymes work not only in an aqueous buffer solution but also in organic solvents.
Greener Synthesis of Natural Products
Published in Ahindra Nag, Greener Synthesis of Organic Compounds, Drugs and Natural Products, 2022
Renata Kołodziejska, Renata Studzińska, Hanna Pawluk, Alina Woźniak
Transaminases (TAs) classified as transferases, participate in the metabolism of amino acids, transform the carbonyl function into an amino moiety. The transaminase-catalyzed reaction requires pyridoxal phosphate (PLP) as a cofactor. Of the two types of PLP-dependent TAs classified according to the type of substrate they convert, the use of α-TAs, exclusively converting α-amino and α-keto acids, is more limited, while ω-TAs can accept substrates with a distal carboxylate group. Depending on the type of transaminase, both keto acids and ketones are tolerated as substrates, thus leading to enantiomerically enriched amino acids and amines, respectively (Figure 14.13).42–44
An insight into the impact of triazophos and deltamethrin pesticides as individual and in combination on oxidative stress and histopathological alterations in Eudrilus eugeniae
Published in Chemistry and Ecology, 2020
Shikha Singh, Rishikesh K. Tiwari, Ravi S. Pandey
The activities of transaminases (ALT and AST) have been considered as potential biomarkers for assessing the toxicity of pesticides in the exposed tissue of organisms. The findings in the present study registered the significant (p < 0.05) elevation in the level of the transaminases activity in different regions of earthworms (Figure 2(A,B)). These results are in accordance with the previous reports of pesticide exposure in earthworm [73] and rats [74] and metal toxicity in earthworm [75]. The possible reason for the increased activity of transaminases was reported in the liver of mammalian systems and may be associated with the input of amino acid into the tricarboxylic acid cycle to overcome the energy crisis during pesticide stress [4].
Schiff base complexes, cancer cell lines, and anticancer evaluation: a review
Published in Journal of Coordination Chemistry, 2022
Sheikh Abdul Majid, Jan Mohammad Mir, Gowhar Jan, Aabid Hussain Shalla
Schiff base ligands form complexes with transition metals that are currently active research area because of their anticancer, antiviral and antimicrobial activities [34–36]. The most important ligands are amino acid based systems which are biologically important [37–40], vital reactive intermediates in many biological reactions. For example, in fructose diphosphate aldolase which constitutes the lysine class, Schiff base is formed as an intermediate involving interaction between the carbonyl group and amino group of the substrate and lysine of the enzyme, respectively. Schiff base also has a role in inducing transamination process whose enzymes such as transaminases are found in the cytosol and mitochondria of eukaryotes [41]. The coordination sites of these ligands are carboxylato oxygen atoms and azomethine nitrogen [42]. Other Schiff base complexes which contain nitrogen and oxygen as donors accelerate the rate of oxidation, reduction, hydrolysis, biocidal activity and other transformations [43–46]. Schiff base ligands display thermochromism and photochromism in solid state due to intramolecular hydrogen bonding between nitrogen and oxygen [47]. Metalloenzymes and metalloproteins are modeled through these complexes [48,49]. Interesting chemical, physical and potentially beneficial chemotherapeutic properties are also exhibited by these complexes [50,51]. Moreover, Schiff bases made from the interaction of transition metal ions and glycylglycine have important biological activities [52,53]; only a few Schiff bases of such type are known [54]. Different properties of this type of complexes paved the way for the synthesis, characterization and studying of the biological activities of new Ni(II), Co(II), Zn(II) and Cu(II) complexes with 4-nitrobenzaldehyde and glycylglycine.