Covalent binding of peroxidized linoleic acid to protein and amino acids as models for lipofuscin formation

Lipids ◽  
1982 ◽  
Vol 17 (12) ◽  
pp. 878-883 ◽  
Author(s):  
Hiroyuki Shimasaki ◽  
Nobuo Ueta ◽  
O. S. Privett
Keyword(s):  
Amino Acids ◽  
Linoleic Acid ◽  
Covalent Binding

Common modifications of selenocysteine in selenoproteins

2019 ◽  
Vol 64 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elias S.J. Arnér
Keyword(s):  
Amino Acids ◽  
Covalent Binding ◽  
Physicochemical Characteristics ◽  
Redox Active

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.

scholarly journals Comparative Analysis on Essential Nutrient Compositions of 23 Wild Hazelnuts (Corylus heterophylla) Grown in Northeast China

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Liying Fan ◽  
Jun Ren ◽  
Yuting Yang ◽  
Limin Zhang
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Northeast China ◽  
Soluble Sugar ◽  
Corylus Avellana ◽  
Essential Nutrient ◽  
New Cultivars ◽  
Nutrient Compositions

The essential nutrients of 23 wild hazelnuts (Corylus heterophylla) grown in northeast China were analyzed in order to sieve good species and study the factors effected on nut quality. Hazelnut kernels contained 45.76–62.78% fat similar to Corylus avellana and main fatty acids were oleic acid (79.75%), linoleic acid (15.42%), palmitic acid (3.29%), and polyunsaturated fatty acids ranged between 10.37% and 25.88%. Average protein, soluble sugar, starch, and ash contents of hazelnut kernels were 25.12%, 4.98%, 2.03%, and 3.04%, respectively. The amount of amino acids, mostly as glutamic acid, arginine, and aspartic acid, was also determined by the hazelnut varieties. The abovementioned variation was explained by growing environmental differences. Among them, the 11th sample was highest in protein content (30.21%) and 18th sample highest in fat content, while the 5th and 14th samples had relatively balanced nutrients. So, when planning to select new cultivars, we primarily considered different hazelnut qualities.

scholarly journals Importance of Highly Conserved Peptide Sites of Human Cytomegalovirus gO for Formation of the gH/gL/gO Complex

2016 ◽  
Vol 91 (1) ◽  
Author(s):  
Cora Stegmann ◽  
Mohamed E. A. Abdellatif ◽  
Kerstin Laib Sampaio ◽  
Paul Walther ◽  
Christian Sinzger
Keyword(s):  
Amino Acids ◽  
Complex Formation ◽  
Human Cytomegalovirus ◽  
Covalent Binding ◽  
Viral Envelope ◽  
Intermediate Phenotype ◽  
Proper Function ◽  
Target Cells ◽  
Trimeric Complex ◽  
Conserved Amino Acids

ABSTRACT The glycoprotein O (gO) is betaherpesvirus specific. Together with the viral glycoproteins H and L, gO forms a covalent trimeric complex that is part of the viral envelope. This trimer is crucial for cell-free infectivity of human cytomegalovirus (HCMV) but dispensable for cell-associated spread. We hypothesized that the amino acids that are conserved among gOs of different cytomegaloviruses are important for the formation of the trimeric complex and hence for efficient virus spread. In a mutational approach, nine peptide sites, containing all 13 highly conserved amino acids, were analyzed in the context of HCMV strain TB40-BAC4 with regard to infection efficiency and formation of the gH/gL/gO complex. Mutation of amino acids (aa) 181 to 186 or aa 193 to 198 resulted in the loss of the trimer and a complete small-plaque phenotype, whereas mutation of aa 108 or aa 249 to 254 caused an intermediate phenotype. While individual mutations of the five conserved cysteines had little impact, their relevance was revealed in a combined mutation, which abrogated both complex formation and cell-free infectivity. C343 was unique, as it was sufficient and necessary for covalent binding of gO to gH/gL. Remarkably, however, C218 together with C167 rescued infectivity in the absence of detectable covalent complex formation. We conclude that all highly conserved amino acids contribute to the function of gO to some extent but that aa 181 to 198 and cysteines 343, 218, and 167 are particularly relevant. Surprisingly, covalent binding of gO to gH/gL is required neither for its incorporation into virions nor for proper function in cell-free infection. IMPORTANCE Like all herpesviruses, the widespread human pathogen HCMV depends on glycoproteins gB, gH, and gL for entry into target cells. Additionally, gH and gL have to bind gO in a trimeric complex for efficient cell-free infection. Homologs of gO are shared by all cytomegaloviruses, with 13 amino acids being highly conserved. In a mutational approach we analyzed these amino acids to elucidate their role in the function of gO. All conserved amino acids contributed either to formation of the trimeric complex or to cell-free infection. Notably, these two phenotypes were not inevitably linked as the mutation of a charged cluster in the center of gO abrogated cell-free infection while trimeric complexes were still being formed. Cysteine 343 was essential for covalent binding of gO to gH/gL; however, noncovalent complex formation in the absence of cysteine 343 also allowed for cell-free infectivity.

scholarly journals Rotavirus-Induced Diarrhea Changes the Proteins, Amino Acids and Fatty Acids Profiles in Fecal Samples of the Infants

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Peng Fei ◽  
Junliang Chen ◽  
Yichao Jiang ◽  
Hongjian Bai ◽  
Yanyan Wang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Linoleic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Docosapentaenoic Acid ◽  
Food Protein ◽  
Isoleucine Leucine ◽  
Automatic Amino Acid Analyzer ◽  
Fecal Samples

Background: Rotavirus-induced diarrhea (RD) could cause disorders in food protein and fat metabolism of infants the changes of which have not been clearly revealed; however, relevant studies are limited. Objectives: The aim was to investigate the changes of proteins, amino acids and fatty acids profiles in fecal samples of the infants caused by RD. Methods: A total of 30 fecal samples were collected from 15 RD infants and 15 healthy infants. The compositions of fecal proteins, amino acids and fatty acids profiles in all fecal samples were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), automatic amino acid analyzer and gas chromatography (GC), respectively. Results: Compared to H infants, the feces in RD infants had lower contents of proteins with 50 - 55, 79 - 80, and 84 - 85 KDa, meanwhile higher contents of proteins with 67 - 69 KDa. The levels of aspartic acid, threonine, serine, glutamic acid, glycinc, alanine, valine, methionine, isoleucine, leucine, lysine, phenylalanine, histidine, arginine, and proline in the feces from RD infants were significantly lower than that of H infants (P < 0.05). The relative proportions of butyric acid, elaidic acid, linoleic acid, cis-11, 14-icotenic acid, cis-11, 14, 17- epoxyeicosatrienoic acids, cis-13, 16-docosanoic acid, and cis-7, 10, 13, 16,19 docosapentaenoic acid in feces from RD infants decreased significantly compared to those of H infants (P < 0.05). On the contrary, significant increases in the relative proportions of caprylic acid, decanoic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, myristoleic acid, palmitic acid, cis-10-heptadecaenoic acid, oleic acid, and γ-linoleic acid were found in the; feces of RD infants (P < .05). Conclusions: RD changed the proteins, amino acids, and fatty acids profiles in infants feces, which improved the understanding of relationship between RD and fecal metabolites profile.

scholarly journals Evaluation of the chemical composition of dry dogfoods commercialized in Chile used for growing dogs

2008 ◽  
Vol 60 (1) ◽  
pp. 218-226 ◽  
Author(s):  
C.A. Alvarado ◽  
S.M. Hodgkinson ◽  
D. Alomar ◽  
D. Boroschek
Keyword(s):  
Amino Acids ◽  
Linoleic Acid ◽  
Crude Protein ◽  
Essential Amino Acids ◽  
High Energy ◽  
Metabolizable Energy ◽  
High Energy Density ◽  
Gross Energy ◽  
Total Fat ◽  
Nutrient Profiles

The nutritional quality of dry dogfood commercialized in Chile for growing dogs was studied. Samples from at least three different batches of 26 dogfood brands were mixed. The resultant samples (n=26) were chemically analyzed to determine their concentrations of dry matter (DM), gross energy, fiber, ash, crude protein, essential amino acids, total fat, linoleic acid and minerals. The metabolizable energy (ME) content of each sample was estimated using modified atwater factors. The results from the chemical analyses were compared with the nutrient profiles published by the American Association of Feed Control Officials (AAFCO). Dogfoods that were found to contain an estimated ME of over 4,000kcal/kg DM were corrected for their high energy density before comparison. All of the dogfoods contained adequate levels of protein, total fat, linoleic acid, iron, copper, manganese and selenium. The concentration of tryptophan was adequate in 92.3% of the samples. All of the other essential amino acids were present in adequate quantities. However, the situation was different for many of the minerals. Only 92.3% of the dogfoods contained an adequate Ca:P ratio. A total of 96.2% of the dogfoods contained an adequate level of Ca, 96.2% for P, 96.2% for Mg, 92.3% for I, 88.5% for Cl, 80.8% for Na, 80.8% for Zn and only 34.6% were adequate for K content. Overall, only 23% of the dogfoods evaluated in this study fulfilled all of the requirements established by the AAFCO in terms of their content of crude protein, amino acids, total fat, linoleic acid, and minerals. It appears that the majority of the dogfoods evaluated in this study (77%) would not satisfy all nutritional requirements of the growing dog.

Duodenal nutrient infusions differentially affect sham feeding and Fos expression in rat brain stem

1998 ◽  
Vol 274 (6) ◽  
pp. R1725-R1733 ◽  
Author(s):  
Curtis B. Phifer ◽  
Hans-Rudolf Berthoud
Keyword(s):  
Amino Acids ◽  
Linoleic Acid ◽  
Area Postrema ◽  
Gastric Distension ◽  
Acid Mixture ◽  
Neural Pathways ◽  
Solitary Tract ◽  
Sham Feeding ◽  
Caloric Value ◽  
Fos Expression

Duodenal infusions of macronutrients inhibit sham and normal feeding. Neural substrates of this response were studied by infusing glucose, linoleic acid, an amino acid mixture, saline, or water into the duodenum of unanesthetized rats and then measuring sham feeding of 30% sucrose or Fos expression in the dorsal vagal complex. Linoleic acid and amino acids (both 1.5 kcal) and glucose (4.5 kcal) suppressed sham feeding relative to control infusions, and all three macronutrients triggered Fos expression in the nucleus of the solitary tract and area postrema. Although there were significant quantitative differences, the subnuclear distribution pattern of Fos-expressing neurons was not different for the three macronutrients and was largely localized to the medial, dorsomedial, and commissural subnuclei of the nucleus of the solitary tract and the area postrema. Linoleic acid suppressed intake and stimulated Fos expression similarly to glucose infusions of three times the caloric value. Amino acids strongly suppressed sham feeding but triggered relatively little Fos expression. These results indicate that the intake-suppressing potency of duodenal macronutrients is dependent on nutrient type, rather than simply caloric value, and that amino acids, although potent inducers of satiety, affect ingestion by processes different from those subserving lipids and carbohydrates. Furthermore, the similar patterns of neuronal activation after different duodenal infusions may indicate a large degree of convergence at the level of primary and second-order sensory neurons, whereas the distinctly different pattern obtained earlier with gastric distension indicates partially separate neural pathways for satiety signals generated by duodenal nutrients and gastric mechanoreceptors.

Linoleic acid oxidation catalyzed by various amino acids and cupric ions in aqueous media

1978 ◽  
Vol 55 (10) ◽  
pp. 703-707 ◽  
Author(s):  
R. S. Farag ◽  
S. A. Osman ◽  
S. A. S. Hallabo ◽  
A. A. Nasr
Keyword(s):  
Amino Acids ◽  
Linoleic Acid ◽  
Aqueous Media ◽  
Acid Oxidation ◽  
Linoleic Acid Oxidation

Revealing the antiaging effects of cereal and food oil derived active substances by Caenorhabditis elegans model

2021 ◽  
Author(s):  
Danling Xu ◽  
Qinlu Lin ◽  
Wei Wu ◽  
Yixin Wu ◽  
Ying Liang
Keyword(s):  
Amino Acids ◽  
Linoleic Acid ◽  
Caenorhabditis Elegans ◽  
Dietary Fiber ◽  
Biological Activities ◽  
Cereal Grains ◽  
Functional Ingredients ◽  
Natural Pigments ◽  
Active Substances

Cereal grains and oils contain various functional ingredients, such as amino acids, peptides, polyphenols, dietary fiber, linoleic acid, and natural pigments. Their biological activities are of great significance. Benefiting from...

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