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Essential amino acids

Abdalla Ahmed Elbashir, Hassan Y Aboul-Enein
Multidimensional gas chromatography (MDGC) is well-established GC method used for a diverse range of applications. Enantioselective MDGC (enantio-MDGC) has been suggested as the method of preference for the separation of extremely overlapping enantiomers. An extensive number of literatures describe enantio-MDGC of polychlorinated biphenyls, essential oils and flavor and fragrance and amino acids were reported. In this review, the applications of MDGC approaches both, heart cutting GC-GC and comprehensive GC × GC in chiral analysis is presented...
March 21, 2018: Critical Reviews in Analytical Chemistry
David Harrich, Hongping Jin
The HIV-1 tat gene encodes a small 86-104 amino acid protein depending on the HIV-1 strain. Tat is essential for HIV-1 replication through interactions with numerous cellular transcription factors. The interaction between Tat and P-TEFb, which is a cellular protein complex composed of cyclin T1 and CDK9, delivers P-TEFb to the newly transcribed viral mRNAs where phosphorylation of RNA polymerase II by CDK9 leads to highly efficient mRNA transcription. It has long been recognized that Tat is a potential anti-HIV-1 target and possibly a viral Achilles' heel...
March 20, 2018: Biochemical Journal
Catarina S H Jesus, Pedro Fernandes Cruz, Luis G Arnaut, Rui M M Brito, Carlos Serpa
The understanding of fast folding dynamics of single α-helices comes mostly from studies on rationally designed peptides displaying sequences with high helical propensity. The folding/unfolding dynamics and energetics of α-helix conformations in naturally occurring peptides remains largely unexplored. Here we report the study of a protein fragment analogue of the C-peptide from bovine pancreatic ribonuclease-A, RN80, a 13-amino acid residue peptide that adopts a highly populated helical conformation in aqueous solution...
March 20, 2018: Journal of Physical Chemistry. B
Yu Xue, Juanjuan Xie, Pan Fang, Jun Yao, Guoquan Yan, Huali Shen, Pengyuan Yang
Glycosylation is a crucial process in protein biosynthesis. However, the analysis of glycopeptides through MS remains challenging due to the microheterogeneity and macroheterogeneity of the glycoprotein. Selective enrichment of glycopeptides from complex samples prior to MS analysis is essential for successful glycoproteome research. In this work, we systematically investigated the behaviors and performances of boronic acid chemistry, ZIC-HILIC, and PGC of glycopeptide enrichment to promote understanding of these methods...
March 20, 2018: Analyst
Vikas C Ghattargi, Yogesh S Nimonkar, Shaunak A Burse, Dimple Davray, Shreyas V Kumbhare, Sudarshan A Shetty, Meghana A Gaikwad, Mangesh V Suryavanshi, Swapnil P Doijad, Bhimashankar Utage, Om Prakash Sharma, Yogesh S Shouche, Bharati S Meti, Shrikant P Pawar
The human gut microbiome plays a crucial role in human health and efforts need to be done for cultivation and characterisation of bacteria with potential health benefits. Here, we isolated a bacterium from a healthy Indian adult faeces and investigated its potential as probiotic. The cultured bacterial strain 17OM39 was identified as Enterococcus faecium by 16S rRNA gene sequencing. The strain 17OM39 exhibited tolerance to acidic pH, showed antimicrobial activity and displayed strong cell surface traits such as hydrophobicity and autoaggregation capacity...
March 19, 2018: Functional & Integrative Genomics
Martha A Zepeda-Rivera, Christina C Saak, Karine A Gibbs
The bacterium Proteus mirabilis can communicate identity through the secretion of the self-identity protein, IdsD, via the type VI secretion (T6S) system. IdsD secretion is essential for self versus non-self recognition behaviors in these populations. Here we provide an answer to the unresolved question of how the activity of a T6S substrate, such as IdsD, is regulated before secretion. We demonstrate that IdsD is found in clusters that form independently of the T6S machinery and activity. We show that the protein IdsC, which is a member of the proposed DUF4123 chaperone family, is essential for the maintenance of these clusters as well as the IdsD protein itself...
March 19, 2018: Journal of Bacteriology
Miljan Simonović, Anupama K Puppala
BACKGROUND: Selenium, an essential dietary micronutrient, is incorporated into proteins as the amino acid selenocysteine (Sec) in response to in-frame UGA codons. Complex machinery ensures accurate recoding of Sec codons in higher organisms. A specialized elongation factor eEFSec is central to the process. SCOPE OF REVIEW: Selenoprotein synthesis relies on selenocysteinyl-tRNASec (Sec-tRNASec ), selenocysteine inserting sequence (SECIS) and other selenoprotein mRNA elements, an in-trans SECIS binding protein 2 (SBP2) protein factor, and eEFSec...
March 16, 2018: Biochimica et Biophysica Acta
Wen-Jia Yang, Kang-Kang Xu, Xin Yan, Chun-Xu Chen, Yu Cao, Yong-Lu Meng, Can Li
Chitin deacetylases (CDAs) are chitin degradation enzymes that strictly regulate growth and development in insects. In this study, we identified and characterized a full-length cDNA of the CDA gene (SpCDA1) in the drugstore beetle, Stegobium paniceum. The open reading frame of SpCDA1 (1614 bp) encoded a 537 amino acid protein, which possessed typical domain structures of CDAs. Phylogenetic comparison to other insect CDAs revealed that SpCDA1 belongs to Group Ib CDAs. Quantitative real-time PCR analyses showed that SpCDA1 was highly expressed in late larval stages...
March 16, 2018: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
Xue-Peng Li, Heng Chi, Jian Zhang
In mammals, beclin-1 is a key player that regulates autophagic activity. In fish, the immune function of beclin-1 is essentially unknown. In this study, we analyzed the involvement of tongue sole (Cynoglossus semilaevis) beclin-1 (named CsBECN1) in antibacterial immunity. CsBECN1 is composed of 451 amino acid residues and shares 84.5-95.1% overall sequence identities with other teleost beclin-1. CsBECN1 possesses a typical Bcl-2 homology domain 3 and an Atg6 domain. Expression of CsBECN1 occurred in multiple tissues and was upregulated during bacterial infection...
March 15, 2018: Fish & Shellfish Immunology
X Dong, Z Zhou, L Wang, B Saremi, A Helmbrecht, Z Wang, J J Loor
Amino acids not only serve as precursors for protein synthesis but also function as signaling molecules that can regulate the mammalian target of rapamycin (mTOR) pathway. Methionine and Lys are the most-limiting AA for milk production and a ratio of ∼3:1 Lys:Met in the metabolizable protein has been determined to be ideal. Besides Met and Lys, recent studies have evaluated Ile, Leu, Val, and Thr as potentially limiting for milk protein synthesis. The objective of this experiment was to determine if varying the ratio of Lys:Thr, Lys:Ile, Lys:Val, and Lys:Leu while maintaining an ideal ratio of Lys:Met and fixed ratio of other essential AA (IPAA) elicits changes in intracellular metabolites, gene transcription related to protein synthesis, and phosphorylation status of mTOR pathway proteins...
March 14, 2018: Journal of Dairy Science
Jinqian Li, Shengjun Feng, Xi Liu, Mingzhe Guo, Mingxiao Chen, Yiyi Chen, Liang Rong, Jinyu Xia, Yuanping Zhou, Jin Zhong, Yi-Ping Li
Genotype 1b strain Con1 represents an important reference in the study of hepatitis C virus (HCV). Here, we aimed to develop an advanced infectious Con1 recombinant. We found that previously identified mutations A1226G/F1464L/A1672S/Q1773H permitted culture adaption of Con1 Core-NS5A (C-5A) recombinant containing 5'UTR and NS5B-3'UTR from JFH1 (genotype 2a), thus acquired additional mutations L725H/F886L/D2415G. C-5A containing all seven mutations (C-5A_7m) replicated efficiently in Huh7.5 and Huh7.5.1 cells and had an increased infectivity in SEC14L2-expressing Huh7...
March 14, 2018: Virology
Mery Munoz-Persy, Alfredo J Lucendo
Eosinophilic esophagitis (EoE) is a unique form of non-IgE-mediated food allergy characterized by esophageal eosinophilic infiltration that commonly causes dysphagia and food impaction in children and adolescents. Assessing the efficacy of dietary restrictions or drug therapies to achieve clinical and histologic resolution of EoE through randomized controlled trials and meta-analyses has resulted in new evidence-based guidelines. Avoiding food triggers is the only therapy targeting the cause of the disease...
March 17, 2018: European Journal of Pediatrics
Julia Karmann, Benedikt Müller, Ulrich Z Hammes
Pathways for assimilates. During their life cycle, plants alternate between a haploid stage, the gametophyte, and a diploid stage, the sporophyte. In higher plants, meiosis generates the gametophyte deeply embedded in the maternal tissue of the flower. The megaspore mother cell undergoes meiosis, and then, the surviving megaspore of the four megaspores produced undergoes mitotic divisions and finally gives rise to the female gametophyte, consisting of the egg cell, two synergids, the central cell, which due to the fusion of two nuclei is diploid (double haploid) in Arabidopsis and most angiosperms and the antipods, whose number is not fixed and varies significantly between species (Yadegari and Drews in Plant Cell 16(Suppl):S133-S141, 2004)...
March 16, 2018: Plant Reproduction
Margherita Ruoppolo, Marianna Caterino, Lucia Albano, Rita Pecce, Maria Grazia Di Girolamo, Daniela Crisci, Michele Costanzo, Luigi Milella, Flavia Franconi, Ilaria Campesi
Sex differences affect several diseases and are organ-and parameter-specific. In humans and animals, sex differences also influence the metabolism and homeostasis of amino acids and fatty acids, which are linked to the onset of diseases. Thus, the use of targeted metabolite profiles in tissues represents a powerful approach to examine the intermediary metabolism and evidence for any sex differences. To clarify the sex-specific activities of liver, heart and kidney tissues, we used targeted metabolomics, linear discriminant analysis (LDA), principal component analysis (PCA), cluster analysis and linear correlation models to evaluate sex and organ-specific differences in amino acids, free carnitine and acylcarnitine levels in male and female Sprague-Dawley rats...
March 16, 2018: Scientific Reports
Teresa Daraio, Ismael Valladolid-Acebes, Kerstin Brismar, Christina Bark
SNAP-25 is a protein involved in regulated membrane fusion and part of the SNARE complex. It exists as two splicing variants, SNAP-25a and SNAP-25b, which differ in 9 out of 206 amino acids. SNAP-25 together with Syntaxin 1 and VAMP-2 forms the ternary SNARE complex essential for mediating activity-dependent release of hormones and neurotransmitters. The functional difference between SNAP-25a and SNAP-25b is poorly understood as both can participate in SNARE complexes and mediate membrane fusion. However, we recently demonstrated that SNAP-25b-deficiency results in metabolic disease and increased insulin secretion...
March 13, 2018: Neuroscience Letters
Renyu Zhang, Michelle J Yoo, Jessica Gathercole, Mariza Gomes Reis, Mustafa M Farouk
Bresaola made from New Zealand mutton and lamb, were compared in quality attributes. Mutton bresaola had slightly lower protein and higher moisture contents, and similar amount of intramuscular fat and instrumental colour compared to that of the lamb. 36 and 80 unique endogenous peptides were observed in mutton and lamb, respectively. Proteolysis during dry-curing was affected by the age of the animal and has resulted in softer and easier to chew textural properties to the mutton bresaola. Significantly higher amounts of total free amino acids and higher proportion of essential amino acids were detected in the mutton bresaola from digestion simulation compared to that from lamb...
July 15, 2018: Food Chemistry
Veronika Dill, Bernd Hoffmann, Aline Zimmer, Martin Beer, Michael Eschbaumer
BACKGROUND: Suspension culture of BHK cells allows large-scale virus propagation and cost-efficient vaccine production, while the shift to animal-component-free cell culture media without serum is beneficial for the quality and downstream processing of the product. Foot-and-mouth disease virus is still endemic in many parts of the world and high-quality vaccines are essential for the eradication of this highly contagious and economically devastating disease. METHODS: Changes to the viral genome sequence during passaging in an adherent and a suspension cell culture system were compared and the impact of amino acid substitutions on receptor tropism, antigenicity and particle stability was examined...
March 16, 2018: Virology Journal
Lokesh K Narnoliya, Rajender S Sangwan, Sudhir P Singh
Rose-scented geranium (Pelargonium sp.) is widely known as aromatic and medicinal herb, accumulating specialized metabolites of high economic importance, such as essential oils, ascorbic acid, and tartaric acid. Ascorbic acid and tartaric acid are multifunctional metabolites of human value to be used as vital antioxidants and flavor enhancing agents in food products. No information is available related to the structural and functional properties of the enzymes involved in ascorbic acid and tartaric acid biosynthesis in rose-scented geranium...
March 15, 2018: Molecular Biology Reports
Dorothy W Gietzen, Sarah H Lindström, James W Sharp, Pok Swee Teh, Michael J Donovan
Background: Low protein amounts are used in ketogenic diets (KDs), where an essential (indispensable) amino acid (IAA) can become limiting. Because the chemically sensitive, seizurogenic, anterior piriform cortex (APC) is excited by IAA limitation, an imbalanced KD could exacerbate seizure activity. Objective: We questioned whether dietary IAA depletion worsens seizure activity in rodents fed KDs. Methods: In a series of 6 trials, male rats or gerbils of both sexes (6-8/group) were given either control diets (CDs) appropriate for each trial, a KD, or a threonine-devoid (ThrDev) diet for ≥7 d, and tested for seizures using various stimuli...
March 1, 2018: Journal of Nutrition
Audrius Gegeckas, Aistė Šimkutė, Renata Gudiukaitė, Donaldas Jonas Čitavičius
Solid keratin-rich waste management is one of essential research area in nowadays. Conventional chemical and high thermal keratin waste decomposition methods are fully explored and not enough effective for future biotechnology perspectives. However, traditional keratin-rich waste decomposition methods could be replaced by environmentally-friendly and economical microbial keratin waste biodegradation methods without energy wastage and essential amino acids and nutrition elements loss. In this study BPKer and BAKer keratinolytic peptidases from Bacillus sp...
March 12, 2018: International Journal of Biological Macromolecules
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