Leucine and sport

2007 ◽  
Vol 277 ◽  
pp. 1-3 ◽  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Enhanced Recovery ◽  
The Other ◽  
Sports Performance ◽  
Other Hand ◽  
Improved Function ◽  
Endurance Activity

In a nutshellExercise increases oxidation of amino acids such as leucine.On the other hand, leucine is a powerful mediator of protein synthesis in muscle, promoting improved function, reduced fatigue and enhanced recovery from exertion. There is RCT evidence that leucine improves sports performance, particularly for endurance activity, but more evidence is still needed.

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Natural Vulcanization Accelerators in Hevea Latex

1948 ◽  
Vol 21 (4) ◽  
pp. 853-859
Author(s):  
R. F. A. Altman
Keyword(s):  
Amino Acids ◽  
Experimental Results ◽  
The Other ◽  
Active Nitrogen ◽  
Nitrogen Bases ◽  
Other Hand ◽  
Decomposition Processes ◽  
Volatile Products ◽  
Nitrogenous Substances ◽  
The One

Abstract As numerous investigators have shown, some of the nonrubber components of Hevea latex have a decided accelerating action on the process of vulcanization. A survey of the literature on this subject points to the validity of certain general facts. 1. Among the nonrubber components of latex which have been investigated, certain nitrogenous bases appear to be most important for accelerating the rate of vulcanization. 2. These nitrogen bases apparently occur partly naturally in fresh latex, and partly as the result of putrefaction, heating, and other decomposition processes. 3. The nitrogen bases naturally present in fresh latex at later stages have been identified by Altman to be trigonelline, stachhydrine, betonicine, choline, methylamine, trimethylamine, and ammonia. These bases are markedly active in vulcanization, as will be seen in the section on experimental results. 4. The nitrogenous substances formed by the decomposition processes have only partly been identified, on the one hand as tetra- and pentamethylene diamine and some amino acids, on the other hand as alkaloids, proline, diamino acids, etc. 5. It has been generally accepted that these nitrogenous substances are derived from the proteins of the latex. 6. Decomposition appears to be connected with the formation of a considerable amount of acids. 7. The production of volatile nitrogen bases as a rule accompanies the decomposition processes. These volatile products have not been identified. 8. The active nitrogen bases, either already formed or derived from complex nitrogenous substances, seem to be soluble in water but only slightly soluble in acetone.

Polysomal organization in growing and resting cultures and its relation to protein synthesis in Tetrahymena

1983 ◽  
Vol 59 (1) ◽  
pp. 121-131
Author(s):  
P. Isberner ◽  
G. Cleffmann
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Growth Conditions ◽  
The Other ◽  
Protein Accumulation ◽  
Resting Cells ◽  
Amino Acid Incorporation ◽  
Total Rna ◽  
Acid Incorporation ◽  
Other Hand

Cytosol from Tetrahymena cells growing at different rates was isolated and separated by centrifugation into polysomal and non-polysomal fractions. The RNAs of either fraction were separated chromatographically into poly(A)+ RNA and poly(A)-RNA. It was found that in resting cultures the total RNA per cell is only about half of that of rapidly growing cultures. All fractions of RNA were reduced proportionally. Thus, the percentage of polysomally bound total RNA (70% of cytosol RNA) and polysomally bound poly(A)+ RNA (72% of cytosol poly(A)+ RNA) is the same in growing and resting cultures. Differences, however, were found in the polysomal structure. Polysomes from resting cultures contained significantly fewer ribosomes. The amounts of RNA bound to polysomes were related to the rate of protein synthesis under different growth conditions. The decrease in cellular RNA corresponded well with the reduction in amino acid incorporation in resting cells. The rate of protein accumulation in resting cells, on the other hand, was considerably less, suggesting that polypeptides in resting cultures are less stable.

scholarly journals Changes of S-alk(en)ylcysteine sulfoxide levels during the growth of different garlic morphotypes

2011 ◽  
Vol 29 (No. 4) ◽  
pp. 373-381 ◽  
Author(s):  
J. Horníčková ◽  
R. Kubec ◽  
J. Velíšek ◽  
CejpekK ◽  
J. Ovesná ◽  
...  
Keyword(s):  
Amino Acids ◽  
Total Content ◽  
Vegetation Period ◽  
The Other ◽  
Flowering Plant ◽  
Other Hand

The contents of three S-alk(en)ylcysteine sulfoxides (alliin, methiin, and isoalliin) were determined in the leaves, pseudostems, and bulbs of six garlic genotypes (two flowering plant morphotypes, two semi bolters, and two scape absent morphotypes) cultivated for five consecutive years at the same location. The average levels of alliin, methiin, and isoalliin were found to be as follows: 1.92, 0.44, and 0.07 mg/g fw in the leaves, 1.57, 0.27, and 0.08 mg/g fw in the pseudostems, and 1.71, 0.20 and 0.13 mg/g fw in the bulbs, respectively. No statistically significant year-to-year differences were observed between the samples. Furthermore, the total contents and relative proportions of S-alk(en)ylcysteine sulfoxides in various parts of the plants (leaves, pseudostems, bulbs and roots) were evaluated in detail during the whole vegetation period. It was observed that the total content of these amino acids gradually decreased in all parts except for the bulbs. In the bulbs, the total content initially decreased after planting but significantly increased in June and culminated before harvest. Analogous trends were also observed for alliin and methiin concentrations. On the other hand, isoalliin levels steadily decreased during the whole vegetation period in all parts of the plants.

scholarly journals Chimeras of X+,K+-ATPases

2001 ◽  
Vol 276 (15) ◽  
pp. 11705-11711 ◽  
Author(s):  
Jan B. Koenderink ◽  
Herman G. P. Swarts ◽  
H. Christiaan Stronks ◽  
Harm P. H. Hermsen ◽  
Peter H. G. M. Willems ◽  
...  
Keyword(s):  
Amino Acids ◽  
The Other ◽  
Β Subunit ◽  
Chimeric Enzyme ◽  
Transmembrane Segments ◽  
Cation Selectivity ◽  
Other Hand ◽  
Atpase Reaction

In this study we reveal regions of Na+,K+-ATPase and H+,K+-ATPase that are involved in cation selectivity. A chimeric enzyme in which transmembrane hairpin M5-M6 of H+,K+-ATPase was replaced by that of Na+,K+-ATPase was phosphorylated in the absence of Na+and showed no K+-dependent reactions. Next, the part originating from Na+,K+-ATPase was gradually increased in the N-terminal direction. We demonstrate that chimera HN16, containing the transmembrane segments one to six and intermediate loops of Na+,K+-ATPase, harbors the amino acids responsible for Na+specificity. Compared with Na+,K+-ATPase, this chimera displayed a similar apparent Na+affinity, a lower apparent K+affinity, a higher apparent ATP affinity, and a lower apparent vanadate affinity in the ATPase reaction. This indicates that theE2K form of this chimera is less stable than that of Na+,K+-ATPase, suggesting that it, like H+,K+-ATPase, de-occludes K+ions very rapidly. Comparison of the structures of these chimeras with those of the parent enzymes suggests that the C-terminal 187 amino acids and the β-subunit are involved in K+occlusion. Accordingly, chimera HN16 is not only a chimeric enzyme in structure, but also in function. On one hand it possesses the Na+-stimulated ATPase reaction of Na+,K+-ATPase, while on the other hand it has the K+occlusion properties of H+,K+-ATPase.

Effect of different oxygen concentrations in the gas phase on biochemical activities of goat mammary tissue in organ culture

1989 ◽  
Vol 56 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Josef Škarda ◽  
Eva Urbanová
Keyword(s):  
Protein Synthesis ◽  
Organ Culture ◽  
Gas Phase ◽  
The Other ◽  
Mammary Tissue ◽  
Relative Response ◽  
Other Hand ◽  
Rna And Protein Synthesis ◽  
Casein Synthesis ◽  
Oxygen Concentrations

SummaryNon-secretory mammary expiants from virgin goats showed higher RNA and protein synthesis in a low O2 gas phase (air) than in high O2 (95% O2). Lipid and casein synthesis was not affected significantly by the concentration of O2 in the atmosphere during culture. on the other hand, the more developed mammary tissue from primigravid goats showed higher lipid, casein and protein synthesis in 95% O2. The relative response of mammary tissue to hormones was not substantially different when cultured in the presence of a low or high O2 gas phase. As Hepes-buffered medium was found not to need a supply of CO2 to maintain the correct pH and as Hepes did not interfere with biochemical activities of cells, it is recommended to use it for cultures in a low O2 gas phase.

scholarly journals Structural and Functional Changes of Reconstituted High-Density Lipoprotein (HDL) by Incorporation of α-synuclein: A Potent Antioxidant and Anti-Glycation Activity of α-synuclein and apoA-I in HDL at High Molar Ratio of α-synuclein

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7485
Author(s):  
Kyung-Hyun Cho
Keyword(s):  
Amino Acids ◽  
Secondary Structure ◽  
Expression System ◽  
Lipoprotein Metabolism ◽  
The Other ◽  
Ldl Oxidation ◽  
Molar Ratio ◽  
Binding Ability ◽  
Functional Changes ◽  
Other Hand

α-synuclein (α-syn) is a major culprit of Parkinson’s disease (PD), although lipoprotein metabolism is very important in the pathogenesis of PD. α-syn was expressed and purified using the pET30a expression vector from an E. coli expression system to elucidate the physiological effects of α-syn on lipoprotein metabolism. The human α-syn protein (140 amino acids) with His-tag (8 amino acids) was expressed and purified to at least 95% purity. Isoelectric focusing gel electrophoresis showed that the isoelectric point (pI) of α-syn and apoA-I were pI = 4.5 and pI = 6.4, respectively. The lipid-free α-syn showed almost no phospholipid-binding ability, while apoA-I showed rapid binding ability with a half-time (T1/2) = 8 ± 0.7 min. The α-syn and apoA-I could be incorporated into the reconstituted HDL (rHDL, molar ratio 95:5:1:1, palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC):cholesterol:apoA-I:α-syn with the production of larger particles (92 Å) than apoA-I-rHDL (86 and 78 Å) and α-syn-rHDL (65 Å). An rHDL containing both apoA-I and α-syn showed lower α-helicity around 45% with a red shift of the Trp wavelength maximum fluorescence (WMF) from 339 nm, while apoA-I-HDL showed 76% α-helicity and 337 nm of WMF. The denaturation by urea addition showed that the incorporation of α-syn in rHDL caused a larger increase in the WMF than apoA-I-rHDL, suggesting that the destabilization of the secondary structure of apoA-I by the addition of α-syn. On the other hand, the addition of α-syn induced two-times higher resistance to rHDL glycation at apoA-I:α-syn molar ratios of 1:1 and 1:2. Interestingly, low α-syn in rHDL concentrations, molar ratio of 1:0.5 (apoA-I:α-syn), did not prevent glycation with more multimerization of apoA-I. In the lipid-free and lipid-bound state, α-syn showed more potent antioxidant activity than apoA-I against cupric ion-mediated LDL oxidation. On the other hand, microinjection of α-syn (final 2 μM) resulted in 10% less survival of zebrafish embryos than apoA-I. A subcutaneous injection of α-syn (final 34 μM) resulted in less tail fin regeneration than apoA-I. Interestingly, incorporation of α-syn at a low molar ratio (apoA-I:α-syn, 1:0.5) in rHDL resulted destabilization of the secondary structure and impairment of apoA-I functionality via more oxidation and glycation. However, at a higher molar ratio of α-syn in rHDL (apoA-I:α-syn = 1:1 or 1:2) exhibited potent antioxidant and anti-glycation activity without aggregation. In conclusion, there might be a critical concentration of α-syn and apoA-I in HDL-like complex to prevent the aggregation of apoA-I via structural and functional enhancement.

scholarly journals Coach-athlete dyad: perception of psychosocial and environmental factors in the relationship - a case study (Pareja entrenador-atleta: percepción de los factores psicosociales y ambientales en la relación – un estudio de caso)

Retos ◽  
2019 ◽  
pp. 666-672
Author(s):  
Pedro Vigário ◽  
Armando Teixeira ◽  
Felício Mendes
Keyword(s):  
Environmental Factors ◽  
Common Factors ◽  
The Other ◽  
Sports Performance ◽  
Other Hand ◽  
Self Knowledge ◽  
The Relationship ◽  
Estudio De Caso

Abstract. In this study, we intended to identify psychosocial and environmental factors common to both, coach and athlete, in a situation of relational dyad, perceived by themselves, in a context of individual sport. In the same way, to perceive which factors were considered most preponderant in the sports performance by the two elements of the dyad. Two interviews were conducted individually, to both coach and athlete, and identified the variables present in this dyad by the coding of the interviews. In the analysis of the collected data, the method used was qualitative. Ten common factors were identified: environment, confidence, empathy, mental exigency, motivation, objectives, perfectionism, resilience, overcoming and values. However, there were significant differences in the relative frequencies of each of these factors, depending on whether they came from the coach or the athlete. It was concluded that, despite the existence of factors common to both subjects, the perception of their significance for the relationship, is not the same. The results also suggest that coaches have a significant focus on the variables of competence. On the other hand, the athletes, in addition to the competence variables, also focus on bond factors such as confidence, or self-knowledge factors such as overcoming.Resumen. En este estudio pretendemos identificar factores psicosociales y ambientales comunes a ambos, entrenador y atleta en situación de pareja relacional, percibidos por los propios, en contexto de modalidad individual. De igual modo, percibir cuáles los factores juzgados más preponderantes en el rendimiento deportivo por los dos elementos de la pareja. Fueron realizadas dos entrevistas, individualmente, a ambos, entrenador y atleta, identificadas las variables presentes en esta pareja a través de la codificación de las entrevistas. En el análisis de los datos recogidos, el método utilizado fue cualitativo. Se identificaron diez factores comunes: ambiente, confianza, empatía, exigencia mental, motivación, objetivos, perfeccionismo, resiliencia, superación y valores. Sin embargo, se verificaron diferencias significativas, en cuanto a las frecuencias relativas de cada uno de estos factores, dependiendo se provenían del entrenador o del atleta. Se concluyó que, a pesar de la existencia de factores comunes a ambos sujetos, la percepción de su significancia para la relación no es igual. Los resultados sugieren que los entrenadores tienen un foco significativo en las variables de cualificaciones. Por otro lado, los atletas, más allá de las variables de cualificación, también tienen foco en factores de vínculo como la confianza, o de autoconocimiento, como la superación.

scholarly journals A versatile and efficient approach for the synthesis of chiral 1,3-nitroamines and 1,3-diamines via conjugate addition to new (S,E)-γ-aminated nitroalkenes derived from L-α-amino acids

2013 ◽  
Vol 9 ◽  
pp. 832-837 ◽  
Author(s):  
Vera Lúcia Patrocinio Pereira ◽  
André Luiz da Silva Moura ◽  
Daniel Pais Pires Vieira ◽  
Leandro Lara de Carvalho ◽  
Eliz Regina Bueno Torres ◽  
...  
Keyword(s):  
Amino Acids ◽  
Direct Reduction ◽  
Conjugate Addition ◽  
The Other ◽  
Triazole Derivative ◽  
Cyanide Anion ◽  
Efficient Approach ◽  
Azide Anion ◽  
Other Hand

New chiral (S,E)-γ-N,N-dibenzylated nitroalkenes 2a–c were synthesized from natural L-(α)-amino acids in five steps with overall yields of 68–88%. The conjugate addition of hydride, methoxide, nitronate and azide nucleophiles to 2a–c led to the corresponding chiral 1,3-nitroamines in 74–90% yield. The conjugate addition of cyanide anion to 2a,b was followed by HNO2 elimination affording chiral aminated acrylonitriles (73–98%). On the other hand, the azide anion reacted with 2a, in acetonitrile, via a [3 + 2]-cycloaddition in which HNO2 was lost, providing the corresponding 1,2,3-triazole derivative. Direct reduction of 1,3-nitroamine derivatives 9a,b produced the corresponding 1,3-diamines in good yields.

The mitochondrial tyrosyl-tRNA synthetase of Podospora anserina is a bifunctional enzyme active in protein synthesis and RNA splicing

1992 ◽  
Vol 12 (2) ◽  
pp. 499-511
Author(s):  
U Kämper ◽  
U Kück ◽  
A D Cherniack ◽  
A M Lambowitz
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Nuclear Gene ◽  
Trna Synthetase ◽  
Podospora Anserina ◽  
The Other ◽  
Group I Introns ◽  
Hybridization Probe ◽  
Significant Similarity ◽  
Group I

The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (mt tyrRS), which is encoded by the nuclear gene cyt-18, functions not only in aminoacylation but also in the splicing of group I introns. Here, we isolated the cognate Podospora anserina mt tyrRS gene, designated yts1, by using the N. crassa cyt-18 gene as a hybridization probe. DNA sequencing of the P. anserina gene revealed an open reading frame (ORF) of 641 amino acids which has significant similarity to other tyrRSs. The yts1 ORF is interrupted by two introns, one near its N terminus at the same position as the single intron in the cyt-18 gene and the other downstream in a region corresponding to the nucleotide-binding fold. The P. anserina yts1+ gene transformed the N. crassa cyt-18-2 mutant at a high frequency and rescued both the splicing and protein synthesis defects. Furthermore, the YTS1 protein synthesized in Escherichia coli was capable of splicing the N. crassa mt large rRNA intron in vitro. Together, these results indicate that YTS1 is a bifunctional protein active in both splicing and protein synthesis. The P. anserina YTS1 and N. crassa CYT-18 proteins share three blocks of amino acids that are not conserved in bacterial or yeast mt tyrRSs which do not function in splicing. One of these blocks corresponds to the idiosyncratic N-terminal domain shown previously to be required for splicing activity of the CYT-18 protein. The other two are located in the putative tRNA-binding domain toward the C terminus of the protein and also appear to be required for splicing. Since the E. coli and yeast mt tyrRSs do not function in splicing, the adaptation of the Neurospora and Podospora spp. mt tyrRSs to function in splicing most likely occurred after the divergence of their common ancestor from yeast.

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