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Background and objectives Circulating branched chain amino acids (BCAAs) increase the risk of type 2 diabetes (T2D). The genetic variants in the BCAA metabolic pathway influence the individual metabolic ability of BCAAs and may affect circulating BCAA levels together with dietary intakes. So, we investigated whether genetic predisposition to impaired BCAA metabolism interacts with dietary BCAA intakes on the risk of type 2 diabetes and related parameters. Methods We estimated dietary BCAA intakes among 434 incident T2D cases and 434 age-matched controls from The Harbin Cohort Study on Diet, Nutrition and Chronic Non-Communicable Diseases. The genetic risk score (GRS) was calculated on the basis of 5 variants having been identified in the BCAA metabolic pathway. Multivariate logistic regression models and general linear regression models were used to assess the interaction between dietary BCAAs and GRS on T2D risk and HbA1c. Results Dietary BCAAs significantly interact with metabolism related GRS on T2D risk and HbA1c (p for interaction = 0.038 and 0.015, respectively). A high intake of dietary BCAAs was positively associated with diabetes incidence only among high GRS (OR 2.40, 95% CI 1.39, 4.12, P for trend = 0.002). Dietary BCAAs were associated with 0.14% elevated HbA1c (p = 0.003) and this effect increased to 0.21% in high GRS (p = 0.003). Furthermore, GRS were associated with 9.19 μmol/L higher plasma BCAA levels (p = 0.006, P for interaction = 0.015) only among the highest BCAA intake individuals. Conclusions Our study suggests that genetic predisposition to BCAA metabolism disorder modifies the effect of dietary BCAA intakes on T2D risk as well as HbA1c and that higher BCAA intakes exert an unfavorable effect on type 2 diabetes risk and HbA1c only among those with high genetic susceptibility.

This experiment was conducted to investigate the effects of leucine (Leu) supplementation on performance and carcass traits of broilers along with the re-evaluation of standardized ileal digestible (SID) Leu requirement of broiler chicks on days 0-14. Birds were fed seven experimental diets with SID Leu levels of 16.3 (basal), 17.3, 18.3, 19.3, 20.3, 21.3, and 22.3 g/kg. Some 280 male broiler chicks were randomly assigned to the seven dietary treatments in a completely randomized design with five replicates. Dietary SID Leu levels had significant effects on body weight gain(BWG), feed conversion ratio(FCR), carcass, and breast percentages. BWG increased (p

Contains fulltext : 225492.pdf (Publisher’s version ) (Open Access) Aberrant fetal growth remains a leading cause of perinatal morbidity and mortality and is associated with a risk of developing non-communicable diseases later in life. We performed a systematic review and meta-analysis combining human and animal studies to assess whether prenatal amino acid (AA) supplementation could be a promising approach to promote healthy fetal growth. PubMed, Embase and Cochrane libraries were searched to identify studies orally supplementing the following AA groups during gestation: (1) arginine family; (2) branched chain (BCAA); (3) methyl donors. Primary outcome was fetal/birth weight. 22 human and 89 animal studies were included in the systematic review. The arginine family, and especially arginine itself, was studied most. Our meta-analysis showed beneficial effects of arginine and (N-Carbamyl) glutamate (NCG), but not aspartic acid and citrulline on fetal/birth weight. However, no effects were reported when isonitrogenous control diet was included. BCAA and methyl donor supplementation did not affect fetal/birth weight. Arginine family supplementation, in particular arginine and NCG, improves fetal growth in complicated pregnancies. BCAA and methyl donor supplementation do not seem to be as promising to target fetal growth. Well controlled research in complicated pregnancies is needed before ruling out AA supplements or preferring arginine above other AAs.

The combination of exercise and nutritional intervention is widely used for stroke patients, as well as frail or sarcopenic older persons. As previously shown, supplemental branched chain amino acids (BCAAs) or protein to gain muscle mass has usually been given just after exercise. This study investigated the effect of the timing of supplemental BCAAs with exercise intervention on physical function in stroke patients. The participants were randomly assigned to two groups based on the timing of supplementation: breakfast (n = 23) and post-exercise (n = 23). The supplement in the breakfast group was provided at 08:00 with breakfast, and in the post-exercise group it was provided just after the exercise session in the afternoon at 14:00&ndash, 18:00. In both groups, the exercise intervention was performed with two sessions a day for two months. The main effects were observed in body fat mass (p = 0.02, confidence interval (CI): 13.2&ndash, 17.7), leg press strength (p = 0.04, CI: 94.5&ndash, 124.5), and Berg balance scale (p = 0.03, CI: 41.6&ndash, 52.6), but no interaction with intake timing was observed. Although the effect of the timing of supplementation on skeletal muscle mass was similar in both groups, BCAA intake with breakfast was effective for improving physical performance and decreasing body fat mass. The results suggest that a combination of BCAA intake with breakfast and an exercise program was effective for promoting rehabilitation of post-stroke patients.

The loss of fat-free mass (FFM) that occurs during weight loss secondary to low-calorie diet can lead to numerous and deleterious consequences. We performed a review to evaluate the state of the art on metabolic and nutritional correlates of loss of fat free mass during low calorie diet and treatment for maintaining fat free mass.This review included 44 eligible studies. There are various diet strategies to maintain FFM during a low-calorie diet, including adoption of a very low carbohydrate ketogenic diet (VLCKD) and taking an adequate amount of specific nutrients (vitamin D, leucine, whey protein).Regarding the numerous and various low-calorie diet proposals for achieving weight loss, the comparison of VLCKD with prudent low-calorie diet found that FFM was practically unaffected by VLCKD. There are numerous possible mechanisms for this, involving insulin and the insulin-like growth factor-1-growth hormone axis, which acts by stimulating protein synthesis.Considering protein and amino acids intake, an adequate daily intake of leucine (4 g/d) and whey protein (20 g/d) is recommended. Regarding vitamin D, if the blood vitamin D has low values (30 ng/mL), it is mandatory that adequate supplementation is provided, specifically calcifediol, because in the obese patient this form is recommended to avoid seizure in the adipose tissue; 3 to 4 drops/d or 20 to 30 drops/wk of calcifediol are generally adequate to restore normal 25(OH)D plasma levels in obese patients.

Traditional AA dose-response studies utilize many animals for evaluation of growth performance, and it is hypothesized that a new experimental design based on modem analytical techniques can reduce the number of used animals. The objective was to evaluate a short-term approach with a low number of pigs based on plasma metabolites as a method to determine the dietary Ile, Leu, and Val requirements. Three separate 6 x 6 Latin square experiments having 6 replicates per treatment were conducted with 6 diets containing increasing concentrations of Ile, Leu, and Val which were fed to 6 pigs (BW 8-9 kg) for 2 days, each without a wash-out period for a period of 12 days. The diets were prepared and used in 3 previous traditional-design dose-response studies and had been stored at 20 degrees C. Blood samples were collected at the end of each 2-day period, and plasma was analyzed for AA and other metabolites using a metabolomics approach. Out of the 18 analyzed plasma AA, 11, 16, and 3 AA for Ile, Leu, or Val, respectively, showed linear or quadratic responses (P < 0.05) which could be linked to animal growth. The same was found for 4 non-AA metabolites in the Ile, and for 7 non-AA metabolites in the Leu study. 3-Methyl-2-oxovaleric acid, ketohexanoic acid, and a-ketoisovaleric acid were discriminating metabolites for both Ile and Leu. It was possible to fit least squares means of 5, 14, and 2 metabolites in the Ile, Leu, and Val experiments to curvilinear-plateau, broken-line, or quadratic models and thereby estimate an optimum dietary BCAA level. The average optimum BCAA levels across metabolites and models were 0.54 standardized ileal digestible (SID) Ile:Lys, 1.04 SID Leu:Lys, and 0.68 SID Val:Lys which were close to optimums of 0.52, 0.93, and 0.70 found in the previous dose response studies based on animal growth performance. In conclusion, certain plasma metabolites could be used to estimate Ile, Leu, and Val requirements, and 2 days of adaptation to a new diet was sufficient to reflect relevant biological changes in the blood to different levels of dietary AA in the current study.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:21:43Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:39:58Z : No. of bitstreams: 1 2-s2.0-30844471131.pdf: 81696 bytes, checksum: 55111da65ac19e48a17d5b3eda002785 (MD5) Made available in DSpace on 2014-05-27T11:21:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Herbicides inhibit enzymatic systems of plants. Acetolactate synthase (ALS, EC = 4.1.3.18) and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, EC 2.5.1.19) are key enzymes for herbicide action. Hundreds of compounds inhibit ALS. This enzyme is highly variable, enabling the selective control of weeds in a number of crops. Glyphosate, the only commercial herbicide inhibiting EPSPS is widely used for non-selective control of weeds in many crops. Recently, transgenic crops resistant to glyphosate were developed and have been used by farmers. The aim of this study was the data mining of eucalypt expressed sequence tags (ESTs) in the FORESTs Genome Project database (https://forests.esalq.usp.br) related to these enzymes. Representative amino acid sequences from the NCBI database associated with ALS and EPSPS were blasted with ESTs from the FORESTs database using the tBLASTx option of the blast tool. The best blasting reads and clusters from FORESTs, represented as nucleotide sequences, were blasted back with the NCBI database to evaluate the level of similarity with available sequences from different species. One and seven clusters were identified as showing high similarity with EPSPS and ALS sequences from the literature, respectively. The alignment of EPSPS sequences allowed the identification of conserved regions that can be used to design specific primers for additional sequencings. Copyright by the Brazilian Society of Genetics. Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias Laboratório de Motologia, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências Laboratório de Xenobióticos, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências Laboratório de Genética, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Melhoramento Vegetal, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Fitopatologia, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Solos, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Entomologia, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agrárias Laboratório de Motologia, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências Laboratório de Xenobióticos, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências Laboratório de Genética, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Melhoramento Vegetal, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Fitopatologia, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Solos, 18603-970 Botucatu, SP Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade Ciências Agrárias Laboratório de Entomologia, 18603-970 Botucatu, SP

A variety of sodium-substrate cotransport systems are known in bacteria. Sodium enters the cell down an electrochemical concentration gradient. There is obligatory coupling between the entry of the ion and the entry of substrate with a stoichiometry (in the cases studied) of 1:1. Thus, the downhill movement of sodium ion into the cell leads to the accumulation of substrate within the cell. The melibiose carrier of Escherichia coli is perhaps the most carefully studied of the sodium cotransport systems in bacteria. This carrier is of special interest because it can also use protons or lithium ions for cotransport. Other sodium cotransport carriers that have been studied recently are for proline, glutamate, serine-threonine, citrate and branched chain amino acids.

In the brain, metabolism of the essential branched chain amino acids (BCAAs) leucine, isoleucine, and valine, is regulated in part by protein synthesis requirements. Excess BCAAs are catabolized or excreted. The first step in BCAA catabolism is catalyzed by the branched chain aminotransferase (BCAT) isozymes, mitochondrial BCATm and cytosolic BCATc. A product of this reaction, glutamate, is the major excitatory neurotransmitter and precursor of the major inhibitory neurotransmitter γ-aminobutyric acid (GABA). The BCATs are thought to participate in a α-keto-acid nitrogen shuttle that provides nitrogen for synthesis of glutamate from α-ketoglutarate. The branched-chain α-keto acid dehydrogenase enzyme complex (BCKDC) catalyzes the second, irreversible step in BCAA metabolism, which is oxidative decarboxylation of the branched-chain α-keto acid (BCKA) products of the BCAT reaction. Maple Syrup Urine Disease (MSUD) results from genetic defects in BCKDC, which leads to accumulation of toxic levels of BCAAs and BCKAs that result in brain swelling. Immunolocalization of BCATm and BCKDC in rats revealed that BCATm is present in astrocytes in white matter and in neuropil, while BCKDC is expressed only in neurons. BCATm appears uniformly distributed in astrocyte cell bodies throughout the brain. The segregation of BCATm to astrocytes and BCKDC to neurons provides further support for the existence of a BCAA-dependent glial-neuronal nitrogen shuttle since the data show that BCKAs produced by glial BCATm must be exported to neurons. Additionally, the neuronal localization of BCKDC suggests that MSUD is a neuronal defect involving insufficient oxidation of BCKAs, with secondary effects extending beyond the neuron. This work was supported by NIH NS-38641 (Susan M. Hutson). Grant sponsor: National Institutes of Health/National Institute of Neurological Disorders and Stroke. Grant Number NS 38641 (Susan M. Hutson).

Twenty-two amino acid substitutions at seven conserved amino acid residues in the acetohydroxyacid synthase (AHAS) gene have been identified to date that confer target-site resistance to AHAS-inhibiting herbicides in biotypes of field-evolved resistant weed species. However, the effect of resistance mutations on AHAS functionality and plant growth has been investigated for only a very few mutations. This research investigates the effect of various AHAS resistance mutations in Lolium rigidum on AHAS functionality and plant growth. The enzyme kinetics of AHAS from five purified L. rigidum populations, each homozygous for the resistance mutations Pro-197-Ala, Pro-197-Arg, Pro-197-Gln, Pro-197-Ser or Trp-574-Leu, were characterized and the pleiotropic effect of three mutations on plant growth was assessed via relative growth rate analysis. All these resistance mutations endowed a herbicide-resistant AHAS and most resulted in higher extractable AHAS activity, with no-to-minor changes in AHAS kinetics. The Pro-197-Arg mutation slightly (but significantly) increased the Km for pyruvate and remarkably increased sensitivity to feedback inhibition by branched chain amino acids. Whereas the Pro-197-Ser and Trp-574-Leu mutations exhibited no significant effects on plant growth, the Pro-197-Arg mutation resulted in lower growth rates. It is clear that, at least in L. rigidum, these five AHAS resistance mutations have no major impact on AHAS functionality and hence probably no plant resistance costs. These results, in part, explain why so many Pro-197 AHAS resistance mutations in AHAS have evolved and why the Pro-197-Ser and the Trp-574-Leu AHAS resistance mutations are frequently found in many weed species. Fil: Yu, Qin. University of Western Australia; Australia Fil: Han, Heping. University of Western Australia; Australia Fil: Vila Aiub, Martin Miguel. University of Western Australia; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Powles, Stephen B.. University of Western Australia; Australia

International audience; Branched-chain amino acids and purine biosynthesis: two pathways essential for optimal growth of Streptococcus thermophilus in milk. Slowing down and delays in Streptococcus thermophilus growth in milk have negative effects for dairy technology. Our objectives are to understand the reasons for those delays, and to identify some of the functions essential for optimal growth of S. thermophilus in milk. To reach this goal, a random insertional mutagenesis was performed on a S. thermophilus strain chosen for its ability to grow rapidly in milk. We obtained 14 different mutants, affected in their capacity to grow quickly in milk. Four of them were further characterized: two were mutated in the branched-chain amino acids biosynthesis operon and two others were mutated in the purine nucleotides biosynthesis operon. Consequently, branched-chain amino acids and purine biosynthesis pathways are functional in S. thermophilus. Our results suggested that the amount of both branched-chain amino acids and purine nucleotides, present in milk, and directly consumable is not sufficient for an optimal growth. Moreover, we identified the branched-chain amino acids and purine biosynthesis pathways as essential functions for optimal growth of S. thermophilus in milk.; Les retards ou ralentissements de croissance de Streptococcus thermophilus, parfois observés dans le lait, ont des conséquences négatives importantes sur le plan technologique. Notre objectif est de comprendre les raisons de ces retards et d'identifier les fonctions qui, chez S. thermophilus, sont essentielles à la croissance optimale dans le lait. Pour atteindre cet objectif, une mutagenèse insertionnelle au hasard a été réalisée sur une souche de S. thermophilus choisie pour sa capacité à se développer rapidement dans le lait. Les mutants pour lesquels la croissance n'est plus optimale dans le lait ont été sélectionnés. Nous avons obtenu 14 mutants distincts affectés dans leur capacité à se développer rapidement dans le lait. Ceux-ci ont été classés en trois groupes selon leur comportement dans différents milieux de culture. Quatre mutants ont été mieux caractérisés : 2 sont atteints dans l'opéron de la biosynthèse des acides aminés à chaîne branchée et les 2 autres dans l'opéron de la biosynthèse des bases puriques. Les voies de biosynthèse des acides aminés à chaîne branchée et des bases puriques sont donc fonctionnelles chez S. thermophilus. Nos résultats suggèrent que les quantités d'acides aminés à chaîne branchée et de bases puriques, assimilables dans le lait par S. thermophilus, ne suffisent pas à une croissance optimale. Ils mettent de plus en évidence que les voies de biosynthèse des acides aminés à chaîne branchée et des purines sont deux fonctions essentielles à la croissance de S. thermophilus dans le lait.