scholarly journals Elucidating the multiple structures of pipecolic acid by rotational spectroscopy

2019 ◽  
Vol 21 (8) ◽  
pp. 4155-4161 ◽  
Author(s):  
A. Simão ◽  
C. Cabezas ◽  
I. León ◽  
E. R. Alonso ◽  
S. Mata ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gas Phase ◽  
Theoretical Data ◽  
Pipecolic Acid ◽  
Conformational Space ◽  
Rotational Spectroscopy ◽  
Multiple Structures ◽  
First Time

The complex conformational space of the non-proteinogenic cyclic amino acid pipecolic acid has been explored in the gas phase for the first time, with 9 conformers characterized via a combination of CP-FTMW and LA-FTMW techniques, supported by theoretical data.

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

Access to 2-Arylquinazolines via Catabolism/Reconstruction of Amino Acids with Insertion of Dimethyl Sulfoxide

2021 ◽  
Author(s):  
Jin-Tian Ma ◽  
Li-Sheng Wang ◽  
Zhi Chai ◽  
Xin-Feng Chen ◽  
Bo-Cheng Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dimethyl Sulfoxide ◽  
Nitrogen Source ◽  
Carbon And Nitrogen ◽  
First Time

Quinazoline skeletons are synthesized by amino acids catabolism/reconstruction combined with dimethyl sulfoxide insertion/cyclization for the first time. The amino acid acts as a carbon and nitrogen source through HI-mediated catabolism...

Disentangling the complex network of non-covalent interactions in fenchone hydrates via rotational spectroscopy and quantum chemistry

2021 ◽  
Author(s):  
Mhamad Chrayteh ◽  
Ecaterina Burevschi ◽  
Donatella Loru ◽  
Therese R. Huet ◽  
Pascal Dréan ◽  
...  
Keyword(s):  
Quantum Chemistry ◽  
Computational Chemistry ◽  
Complex Network ◽  
Microwave Spectroscopy ◽  
Rotational Spectroscopy ◽  
Non Covalent Interactions ◽  
First Time ◽  
Covalent Interactions

The hydrates of the monoterpenoid fenchone (C10H16O).(H2O)n (n=1,2,3) were investigated both by computational chemistry and microwave spectroscopy. Two monohydrates, three dihydrates and for the first time three trihydrates have been...

scholarly journals Modeling Interactions between an Amino Acid and a Metal Dication: Cysteine-Calcium(II) Reactions in the Gas Phase

ChemPlusChem ◽  
2013 ◽  
Vol 78 (9) ◽  
pp. 1124-1133 ◽  
Author(s):  
Marcela Hurtado ◽  
Manuel Monte ◽  
Al Mokhtar Lamsabhi ◽  
Manuel Yáñez ◽  
Otilia Mó ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gas Phase ◽  
Modeling Interactions

CsOH and its Lighter Homologues – a Comparison

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1229-1236
Author(s):  
Matthias Wörsching ◽  
Constantin Hoch
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Structure Type ◽  
Alkali Metal Hydroxide ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Cesium Hydroxide ◽  
Free Ion ◽  
The One ◽  
First Time

Abstract Cesium hydroxide, CsOH, was for the first time characterised on the basis of single-crystal data. The structure is isotypic to the one of the room-temperature modification of NaOH and can be derived from the NaCl structure type thus allowing the comparison of all alkali metal hydroxide structures. Raman spectroscopic investigations show the hydroxide anion to behave almost as a free ion as in the gas phase. The X-ray investigations indicate possible H atom positions.

scholarly journals Distal substitutions drive divergent DNA specificity among paralogous transcription factors through subdivision of conformational space

2015 ◽  
Vol 113 (2) ◽  
pp. 326-331 ◽  
Author(s):  
William H. Hudson ◽  
Bradley R. Kossmann ◽  
Ian Mitchelle S. de Vera ◽  
Shih-Wei Chuo ◽  
Emily R. Weikum ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Amino Acid ◽  
Dna Binding ◽  
Glucocorticoid Receptor ◽  
Binding Specificity ◽  
Conformational Space ◽  
Amino Acid Substitutions ◽  
Ancestral Gene ◽  
Response Elements ◽  
Binding Interface

Many genomes contain families of paralogs—proteins with divergent function that evolved from a common ancestral gene after a duplication event. To understand how paralogous transcription factors evolve divergent DNA specificities, we examined how the glucocorticoid receptor and its paralogs evolved to bind activating response elements [(+)GREs] and negative glucocorticoid response elements (nGREs). We show that binding to nGREs is a property of the glucocorticoid receptor (GR) DNA-binding domain (DBD) not shared by other members of the steroid receptor family. Using phylogenetic, structural, biochemical, and molecular dynamics techniques, we show that the ancestral DBD from which GR and its paralogs evolved was capable of binding both nGRE and (+)GRE sequences because of the ancestral DBD’s ability to assume multiple DNA-bound conformations. Subsequent amino acid substitutions in duplicated daughter genes selectively restricted protein conformational space, causing this dual DNA-binding specificity to be selectively enhanced in the GR lineage and lost in all others. Key substitutions that determined the receptors’ response element-binding specificity were far from the proteins’ DNA-binding interface and interacted epistatically to change the DBD’s function through DNA-induced allosteric mechanisms. These amino acid substitutions subdivided both the conformational and functional space of the ancestral DBD among the present-day receptors, allowing a paralogous family of transcription factors to control disparate transcriptional programs despite high sequence identity.

scholarly journals The effects of solution additives and gas‐phase modifiers on the molecular environment and conformational space of common heme proteins

2019 ◽  
Vol 33 (5) ◽  
pp. 399-404 ◽  
Author(s):  
David Butcher ◽  
Jaroslava Miksovska ◽  
Mark E. Ridgeway ◽  
Melvin A. Park ◽  
Francisco Fernandez‐Lima
Keyword(s):  
Gas Phase ◽  
Heme Proteins ◽  
Conformational Space

scholarly journals Molecular characterization of Prunus necrotic ringspot virus isolated from rose in Brazil

2015 ◽  
Vol 45 (12) ◽  
pp. 2197-2200 ◽  
Author(s):  
Thor Vinícius Martins Fajardo ◽  
Monique Bezerra Nascimento ◽  
Marcelo Eiras ◽  
Osmar Nickel ◽  
Gilvan Pio-Ribeiro
Keyword(s):  
Amino Acid ◽  
Molecular Characterization ◽  
Molecular Analysis ◽  
Nucleotide Sequences ◽  
Amino Acid Sequences ◽  
Causal Agent ◽  
Ringspot Virus ◽  
Prunus Necrotic Ringspot Virus ◽  
First Time

ABSTRACT: There is no molecular characterization of Brazilian isolates of Prunus necrotic ringspot virus (PNRSV), except for those infecting peach. In this research, the causal agent of rose mosaic was determined and the movement (MP) and coat (CP) protein genes of a PNRSV isolate from rose were molecularly characterized for the first time in Brazil. The nucleotide and deduced amino acid sequences of MP and CP complete genes were aligned and compared with other isolates. Molecular analysis of the MP and CP nucleotide sequences of a Brazilian PNRSV isolate from rose and others from this same host showed highest identities of 96.7% and 98.6%, respectively, and Rose-Br isolate was classified in PV32 group.

Analysis of chlorinated hydrocarbons in gas phase using a portable membrane inlet mass spectrometer

2016 ◽  
Vol 8 (36) ◽  
pp. 6607-6615 ◽  
Author(s):  
Stamatios Giannoukos ◽  
Boris Brkić ◽  
Stephen Taylor
Keyword(s):  
Gas Phase ◽  
Mass Spectrometer ◽  
Gaseous Phase ◽  
Chlorinated Hydrocarbons ◽  
Volatile Chlorinated Hydrocarbons ◽  
First Time

A compact portable membrane inlet mass spectrometer (MIMS) has been used for the first time to detect and monitor, both qualitatively and quantitatively, volatile chlorinated hydrocarbons in the gaseous phase.

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