Differential geometry and protein conformation. V. Medium-range conformational influence of the individual amino acids

Biopolymers ◽  
1987 ◽  
Vol 26 (7) ◽  
pp. 1163-1187 ◽  
Author(s):  
S. Rackovsky ◽  
D. A. Goldstein
Keyword(s):  
Amino Acids ◽  
Differential Geometry ◽  
Protein Conformation ◽  
Medium Range ◽  
The Individual

scholarly journals Radical Hemithoracic Radiotherapy Induces Systemic Metabolomics Changes That Are Associated with the Clinical Outcome of Malignant Pleural Mesothelioma Patients

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 508
Author(s):  
Emanuela Di Gregorio ◽  
Gianmaria Miolo ◽  
Asia Saorin ◽  
Elena Muraro ◽  
Michela Cangemi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Overall Survival ◽  
Clinical Outcome ◽  
Malignant Pleural Mesothelioma ◽  
Therapeutic Option ◽  
Enrichment Analysis ◽  
Metabolic Effects ◽  
Pleural Mesothelioma ◽  
Polyamine Biosynthesis ◽  
The Individual

Radical hemithoracic radiotherapy (RHRT) represents an advanced therapeutic option able to improve overall survival of malignant pleural mesothelioma patients. This study aims to investigate the systemic effects of this radiotherapy modality on the serum metabolome and their potential implications in determining the individual clinical outcome. Nineteen patients undergoing RHRT at the dose of 50 Gy in 25 fractions were enrolled. Serum targeted metabolomics profiles were investigated at baseline and the end of radiotherapy by liquid chromatography and tandem mass spectrometry. Univariate and multivariate OPLS-DA analyses were applied to study the serum metabolomics changes induced by RHRT while PLS regression analysis to evaluate the association between such changes and overall survival. RHRT was found to affect almost all investigated metabolites classes, in particular, the amino acids citrulline and taurine, the C14, C18:1 and C18:2 acyl-carnitines as well as the unsaturated long chain phosphatidylcholines PC ae 42:5, PC ae 44:5 and PC ae 44:6 were significantly decreased. The enrichment analysis showed arginine metabolism and the polyamine biosynthesis as the most perturbed pathways. Moreover, specific metabolic changes encompassing the amino acids and acyl-carnitines resulted in association with the clinical outcome accounting for about 60% of the interpatients overall survival variability. This study highlighted that RHRT can induce profound systemic metabolic effects some of which may have a significant prognostic value. The integration of metabolomics in the clinical assessment of the malignant pleural mesothelioma could be useful to better identify the patients who can achieve the best benefit from the RHRT treatment.

scholarly journals Fluorescent Probes with Unnatural Amino Acids to Monitor Proteasome Activity in Real-Time

2020 ◽  
Author(s):  
Breanna L. Zerfas ◽  
Rachel A. Coleman ◽  
Andres Salazar Chaparro ◽  
Nathaniel J. Macatangay ◽  
Darci Trader
Keyword(s):  
Amino Acids ◽  
Small Molecule ◽  
Fluorescent Probes ◽  
Unnatural Amino Acids ◽  
Cell Types ◽  
Proteasome Activity ◽  
Live Cells ◽  
Fluorescent Substrate ◽  
The Individual ◽  
Small Molecule Modulators

<div> <div> <div> <p>The proteasome is an essential protein complex that, when dysregulated, can result in various diseases in eukaryotic cells. As such, understanding the enzymatic activity of the proteasome and what can alter it is crucial to elucidating its roles in these diseases. This can be done effectively by using activity-based fluorescent substrate probes, of which there are many commercially available that target the individual protease-like subunits in the 20S CP of the proteasome. Unfortunately, these probes have not displayed appropriate characteristics for their use in live cell-based assays. In the work presented here, we have developed a set of probes which have shown improved fluorescence properties and selectivity towards the proteasome compared to other cellular proteases. By including unnatural amino acids, we have found probes which can be utilized in various applications, including monitoring the effects of small molecule stimulators of the proteasome in live cells and comparing the relative proteasome activity across different cancer cell types. In future studies, we expect the fluorescent probes presented here will serve as tools to support the discovery and characterization of small molecule modulators of proteasome activity. </p> </div> </div> </div>

scholarly journals Neuronal-glial metabolism under depolarizing conditions. A 13C-n.m.r. study

1992 ◽  
Vol 282 (1) ◽  
pp. 225-230 ◽  
Author(s):  
R S Badar-Goffer ◽  
O Ben-Yoseph ◽  
H S Bachelard ◽  
P G Morris
Keyword(s):  
Amino Acids ◽  
Glial Cells ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Maximum Percentage ◽  
Theoretical Maximum ◽  
Metabolic Pool ◽  
Time Courses ◽  
The Individual

Time courses of incorporation of 13C from 13C-labelled glucose and/or acetate into the individual carbon atoms of amino acids, citrate and lactate in depolarized cerebral tissues were monitored by using 13C-n.m.r. spectroscopy. There was no change in the maximum percentage of 13C enrichments of the amino acids on depolarization, but the maxima were reached more rapidly, indicating that rates of metabolism in both glycolysis and the tricarboxylic acid cycle were accelerated. Although labelling of lactate and of citrate approached the theoretical maximum of 50%, labelling of the amino acids was always below 20%, suggesting that there is a metabolic pool or compartment that is inaccessible to exogenous substrates. Under resting conditions labelling of citrate and of glutamine from [1-13C]glucose was not detected, whereas both were labelled from [2-13C]acetate, which is considered to reflect glial metabolism. In contrast, considerable labelling of these two metabolites from [1-13C]glucose was observed in depolarized tissues, suggesting that the increased metabolism may be due to increased consumption of glucose by glial cells. The labelling patterns on depolarization from [1-13C]glucose alone and from both precursors [( 1-13C]glucose plus [2-13C]acetate) were similar, which also indicates that the changes are due to increased consumption of glucose rather than acetate.

scholarly journals Comparison of the isotope dilution method for determination of the ileal endogenous amino acid losses with labelled diet and labelled pigs

2000 ◽  
Vol 83 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Vincent Hess ◽  
Philippe Ganier ◽  
Jean-Noel Thibault ◽  
Bernard Sève
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Latin Square ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
First Case ◽  
Endogenous Protein ◽  
The Individual ◽  
Protein Free Diet

The aims of the present study were first to compare the amino acid dilution method performed using labelled animals with that using labelled diets, and second to determine real digestibilities and total ileal endogenous losses of N and amino acids. Two diets containing pea cultivars (Solara and Amino) and a protein-free diet were compared in a 3 × 3 Latin-square experiment. The three pigs were each prepared with an ileo-rectal anastomosis and were continuously infused with [1-13C]leucine. For each cultivar,15N-labelled and unlabelled diets were formulated. The real digestibility and endogenous losses of leucine were higher when obtained by labelling the pig than by labelling the foodstuff. This was due either to the inadequate estimation of the endogenous protein enrichment in the first case or to the importance of dietary N recycling in the second case. However, in both cases the ileal endogenous losses of N and amino acids were higher than the basal losses determined with the protein-free diet. There were significant differences between the two pea cultivars in terms of phenylalanine and leucine when measured with labelled diets. It is suggested that, although ileal endogenous losses may be underestimated, using labelled feedstuffs is of great interest due to the direct estimation of the individual amounts of amino acids.

scholarly journals The effect of hypermethylation on the functional properties of transfer ribonucleic acid. Formation of aminoacyl-transfer-ribonucleic acid

1969 ◽  
Vol 114 (2) ◽  
pp. 429-435 ◽  
Author(s):  
David J. Pillinger ◽  
John Hay ◽  
Ernest Borek
Keyword(s):  
Amino Acids ◽  
Ribonucleic Acid ◽  
Control Sample ◽  
Transfer Rna ◽  
E Coli ◽  
Functional Sites ◽  
The Individual ◽  
Almost All ◽  
Aminoacyl Transfer ◽  
Kinetics Of

1. The ability of chemically hypermethylated Escherichia coli B transfer RNA to accept 19 amino acids was studied and the results were compared with those obtained with a control sample of E. coli B transfer RNA incubated under similar conditions in the absence of methylating agent. 2. There is a marked decrease in the ability of the modified transfer RNA to accept amino acids in almost all instances. 3. The acceptance of cysteine appears to be unique in that it is enhanced in the hypermethylated transfer RNA. 4. More detailed studies on the kinetics of acceptance for six amino acids is presented, emphasizing the variation in response of the individual amino acids. 5. Increasing hypermethylation causes a progressive decrease in the amino acid acceptance. 6. The results are discussed in terms of methylation at functional sites within the transfer RNA and possible conformational alterations to the structure of the macromolecule.

Mutual effects between aromatic amino acids and guanosine upon vitamin B2 photosensitization in the presence of visible light

2013 ◽  
Vol 91 (8) ◽  
pp. 684-690
Author(s):  
M. Paulina Montaña ◽  
Gabriela Ferrari ◽  
Eduardo Gatica ◽  
José Natera ◽  
Walter Massad ◽  
...  
Keyword(s):  
Amino Acids ◽  
Visible Light ◽  
Superoxide Radical ◽  
Marked Decrease ◽  
Aromatic Amino Acids ◽  
Quantum Yields ◽  
Vitamin B2 ◽  
Singlet Molecular Oxygen ◽  
Superoxide Radical Anion ◽  
The Individual

Considering the importance of the visible-light-induced photodynamic effect in complex bioenvironments, mutual effects between the individual aromatic amino acids (AAs) tyrosine (Tyr), tryptophan (Trp), and histidine (His) and the nucleoside guanosine (GUO) were investigated in pH 7 aqueous solution with vitamin B2 (riboflavin (Rf)) as a dye sensitizer. The quantum yields of oxygen uptake (Φ–O2) for most of the AA−GUO mixtures studied, taken as a measure of overall photooxidation susceptibility, are not straightforwardly predictable from the individual behaviour of the components of the mixture. The final result depends on several connected factors, such as the respective abilities of the substrates as quenchers of the long-lived Rf triplet excited state and the generated reactive oxygen species singlet molecular oxygen (O2(1Δg)) and superoxide radical anion ([Formula: see text]). A mechanistic interpretation of the Rf-sensitized results can be roughly resumed as follows: Tyr at pH 7 exerts a protective effect on the photooxidation of the mixture Tyr−GUO due to the O2(1Δg) physical quenching by the AA. The same effect was observed for Trp−GUO and His−GUO at pH 7. In these cases, it is attributed to the quenching of 3Rf* by GUO in detriment of the Type II route. For the system Tyr−GUO at pH 9, a marked decrease in the Φ–O2 occurred for the mixture as compared with the respective Φ–O2 for the individual components. It was ascribed to the participation of a radical-mediated mechanism without oxygen consumption in a competitive pathway with the [Formula: see text]-mediated route.

scholarly journals Macronutrients in Parenteral Nutrition: Amino Acids

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 772
Author(s):  
Roberto Iacone ◽  
Clelia Scanzano ◽  
Lidia Santarpia ◽  
Iolanda Cioffi ◽  
Franco Contaldo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Parenteral Nutrition ◽  
Hospital Pharmacy ◽  
Energy Requirements ◽  
Clinical Benefits ◽  
Nutritional Needs ◽  
Muscle Mass Loss ◽  
The Individual ◽  
The Right

The right amount and quality of amino acids (AAs) supplied to patients on parenteral nutrition (PN) reduces muscle mass loss, may preserve or even increase it, with significant clinical benefits. Several industrial PN mixtures are available so that nutrition specialists can choose the product closest to the patient’s needs. In selected cases, there is the possibility of personalizing compounded mixtures in a hospital pharmacy that completely meets the individual nutritional needs of PN patients. This narrative review deals with the AA solutions used in PN mixtures. The physiology, the methods to calculate the AA needs, and the AA and energy requirements suggested by scientific guidelines for each patient type are also reported.

The Renal Aminoacidurias

1963 ◽  
Vol 9 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Harold A Harper ◽  
Paul D Doolan
Keyword(s):  
Amino Acids ◽  
Glomerular Filtration ◽  
Maximum Rate ◽  
Renal Tubule ◽  
Renal Tubules ◽  
Naturally Occurring ◽  
Clinical Interest ◽  
The Individual ◽  
Filtered Load ◽  
Metabolic Significance

Abstract The normal mechanisms whereby the renal tubules handle amino acids are reviewed as a basis for interpretation of the physiologic causes of the renal aminoacidurias. Under normal circumstances, the renal tubules reabsorb in excess of 93% of the amino acids filtered from the plasma. When the filtered load of amino acids is increased, as by intravenous injection of amino acids, there is an increase in both the amounts reabsorbed and those excreted, but the ability of the renal tubule to respond to an increased filtered load of amino acids is so great that a maximum rate of reabsorption has not been found in the human. However, the tubule does exhibit selectivity with respect to the reabsorption of each of the naturally occurring L-amino acids; furthermore, there is a much greater efficiency of reabsorption of the L as compared to the D isomers of the individual amino acids. The excretion of amino acids is influenced to an important degree by the glomerular filtration rate, as exemplified by studies in pregnant subjects as well as patients with renal disease affecting glomerular filtration. Several renal aminoacidurias of clinical interest are discussed with special reference to their diagnostic and metabolic significance.

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