Zwitterion to normal formation of L-Alanine in water solvation as an ultrasonic impact from their Gibbs energy barrier: Experiment with different molarities and DFT simulation for few basis sets

l-Alanine has Physiological significance, and their molecular interaction is subjected to the Gibbs energy barrier. The present study has reported the Gibb's energy barrier of l-Alanine (l-Ala) from 20.095 to 20.055 KJ/mol by performing the ultrasonic experiment at 4 MHz for 0.0075 M to 0.01 M l-Ala in water solvation. This barrier is also analyzed by DFT for the six distinct types of basis sets. The smallest barrier of a normal to zwitterion conversion has been identified for the SVP and def2-SVPas -22.08 KJ/molby DFT. Their absolute values reported near to the experimental estimated values by regression (as 20.2 KJ/mol). Few thermodynamic potentials are also analyzed. The study is further rendering to predict the bandgap, quantum descriptors, and their changes in account of chemical reactivity, stability for the different basis sets. Ultrasonic stimulation is seen responsible for reverting the form. Detail about necessary fundamental aspects have been discussed successfully.

Evaluating amino acids as protectants against β-N-methylamino-l-alanine-induced developmental neurotoxicity in a rat model

With accumulating evidence that supports the role of β-N-methylamino-l-alanine (BMAA) in neurodegeneration, it is necessary to elucidate the mechanisms and modes of BMAA toxicity so as to facilitate the search for potential preventative/therapeutic strategies. Daily supplementation with l-serine was suggested as a possible therapy to treat BMAA-induced neurotoxicity, based on the hypothesized mechanism of BMAA misincorporation into proteins for l-serine. As an alternative to misincorporation, it was hypothesized that BMAA toxicity may, in part, be due to its high affinity for associating with hydroxyl group-containing amino acids, and that a dietary excess of the hydroxyl-containing l-serine might offer protection by binding to BMAA and reducing its toxicity. Additionally, l-serine can also reduce the uptake of BMAA into human cells by competitive uptake at ASCT2, and l-phenylalanine, by competitive uptake at LAT1, and l-alanine, by competitive uptake at SNAT2, can also reduce BMAA uptake into human cells. The aim of this study was therefore to determine the protective value of l-serine, l-phenylalanine and l-alanine in reducing the effects of neonatal exposure to BMAA in a Sprague Dawley rat model. Pre-treatment with l-phenylalanine reduced the observed behavioral abnormalities and neuropathologies by 60-70% in most cases. l-serine was also effective in reducing some of the behavioral abnormalities and neuropathologies, most markedly spinal cord neuronal loss. However, the protective effect of l-serine was obfuscated by neuropathies that were observed in l-serine-treated control male rats. l-alanine had no effect in protecting against BMAA-induced neurotoxicity, suggesting that competitive amino acid uptake plays a minor role in protecting against BMAA-induced neurotoxicity.

Expression of the alaE gene is positively regulated by the global regulator Lrp in response to intracellular accumulation of l-alanine in Escherichia coli

The alaE gene in Escherichia coli encodes an l-alanine exporter that catalyzes the active export of l-alanine using proton electrochemical potential. In our previous study, alaE expression was shown to increase in the presence of l-alanyl-l-alanine (Ala-Ala). In this study, the global regulator leucine-responsive regulatory protein (Lrp) was identified as an activator of the alaE gene. A promoter less β-galactosidase gene was fused to an alaE upstream region (240 nucleotides). Cells that were lacZ-deficient and harbored this reporter plasmid showed significant induction of β-galactosidase activity (approximately 17-fold) in the presence of 6 mM l-alanine, l-leucine, and Ala-Ala. However, a reporter plasmid possessing a smaller alaE upstream region (180 nucleotides) yielded transformants with strikingly low enzyme activity under the same conditions. In contrast, lrp-deficient cells showed almost no β-galactosidase induction, indicating that Lrp positively regulates alaE expression. We next performed an electrophoretic mobility shift assay (EMSA) and a DNase I footprinting assay using purified hexahistidine-tagged Lrp (Lrp-His). Consequently, we found that Lrp-His binds to the alaE upstream region spanning nucleotide -161 to -83 with a physiologically relevant affinity (apparent K_D, 288.7 ± 83.8 nM). Furthermore, the binding affinity of Lrp-His toward its cis-element was increased by l-alanine and l-leucine, but not by Ala-Ala and d-alanine. Based on these results, we concluded that the gene expression of the alaE is regulated by Lrp in response to intracellular levels of l-alanine, which eventually leads to intracellular homeostasis of l-alanine concentrations.

Triazolyl phenyl disulfides: 8-Amino-7-oxononanoate synthase inhibitors as potential herbicides

The chemical validation of a potential herbicide target was investigated with 8-amino-7-oxononanoate synthase (AONS, also known as 7-keto-8-aminopelargonate synthase, KAPAS) and triazolyl phenyl disulfide derivatives in vitro and in vivo. AONS activity was completely inhibited by these synthesized compounds, with an IC50 of 48 to 592μM in vitro. Forty five-day old Arabidopsis thaliana plants were completely killed by representative compound KHG23844 {N-(2-fluorophenyl)-3-(phenyldisulphanyl)-1H-1,2,4-triazole-1-carboxamide} at the application rate of 250gha(-1) of foliar treatment in greenhouse conditions. Foliar application of 1000gha(-1) KHG23844 induced 2.3-fold higher l-alanine accumulation in the treated A. thaliana plants. Foliar supplement of 1mM biotin at 1 and 2days before KHG23844 application effectively recovered the growth inhibition of A. thaliana plant treated with KHG23844. The results strongly suggested that representative compound KHG23844 and its derivatives are potential AONS inhibitors.

On the existence of 'L-alanine cadmium bromide'

It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.