Pathways for the asymmetric amplification of protein amino acids in the Murchison meteorite

2010 ◽  
Author(s):  
Michael H. Engel ◽  
Stephen A. Macko
Keyword(s):  
Amino Acids ◽  
Murchison Meteorite ◽  
Protein Amino Acids

scholarly journals Nectar non-protein amino acids (NPAAs) do not change nectar palatability but enhance learning and memory in honey bees

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniele Carlesso ◽  
Stefania Smargiassi ◽  
Elisa Pasquini ◽  
Giacomo Bertelli ◽  
David Baracchi
Keyword(s):  
Amino Acids ◽  
Learning And Memory ◽  
Honey Bees ◽  
Feeding Preference ◽  
Memory Retention ◽  
Floral Nectar ◽  
Olfactory Conditioning ◽  
Specific Memory ◽  
Protein Amino Acids ◽  
Valuable Compounds

AbstractFloral nectar is a pivotal element of the intimate relationship between plants and pollinators. Nectars are composed of a plethora of nutritionally valuable compounds but also hundreds of secondary metabolites (SMs) whose function remains elusive. Here we performed a set of behavioural experiments to study whether five ubiquitous nectar non-protein amino acids (NPAAs: β-alanine, GABA, citrulline, ornithine and taurine) interact with gustation, feeding preference, and learning and memory in Apis mellifera. We showed that foragers were unable to discriminate NPAAs from water when only accessing antennal chemo-tactile information and that freely moving bees did not exhibit innate feeding preferences for NPAAs. Also, NPAAs did not alter food consumption or longevity in caged bees over 10 days. Taken together our data suggest that natural concentrations of NPAAs did not alter nectar palatability to bees. Olfactory conditioning assays showed that honey bees were more likely to learn a scent when it signalled a sucrose reward containing either β-alanine or GABA, and that GABA enhanced specific memory retention. Conversely, when ingested two hours prior to conditioning, GABA, β-alanine, and taurine weakened bees’ acquisition performances but not specific memory retention, which was enhanced in the case of β-alanine and taurine. Neither citrulline nor ornithine affected learning and memory. NPAAs in nectars may represent a cooperative strategy adopted by plants to attract beneficial pollinators.

Protection of Italian ryegrass (Lolium multiflorum L.) seedlings from salinity stress following seed priming with L-methionine and casein hydrolysate

2020 ◽  
pp. 1-9
Author(s):  
Keum-Ah Lee ◽  
Youngnam Kim ◽  
Hossein Alizadeh ◽  
David W.M. Leung
Keyword(s):  
Oxidative Stress ◽  
Amino Acids ◽  
Salinity Stress ◽  
Lolium Multiflorum ◽  
Casein Hydrolysate ◽  
Seed Priming ◽  
Germination Percentage ◽  
Italian Ryegrass ◽  
Significant Difference ◽  
Protein Amino Acids

Abstract Seed priming with water (hydropriming or HP) has been shown to be beneficial for seed germination and plant growth. However, there is little information on the effects of seed priming with amino acids and casein hydrolysate (CH) compared with HP, particularly in relation to early post-germinative seedling growth under salinity stress. In this study, Italian ryegrass seeds (Lolium multiflorum L.) were primed with 1 mM of each of the 20 protein amino acids and CH (200 mg l−1) before they were germinated in 0, 60 and 90 mM NaCl in Petri dishes for 4 d in darkness. Germination percentage (GP), radicle length (RL) and peroxidase (POD) activity in the root of 4-d-old Italian ryegrass seedlings were investigated. Generally, when the seeds were germinated in 0, 60 and 90 mM NaCl, there was no significant difference in GP of seeds among various priming treatments, except that a higher GP was observed in seeds of HP treatment compared with the non-primed seeds when incubated in 60 mM NaCl. When incubated in 60 and 90 mM NaCl, seedlings from seeds primed with L-methionine or CH exhibited greater RL (greater protection against salinity stress) and higher root POD activity than those from non-primed and hydro-primed seeds. Under salinity stress, there were higher levels of malondialdehyde (MDA) in the root of 4-d-old Italian ryegrass seedlings, a marker of oxidative stress, but seed priming with CH was effective in reducing the salinity-triggered increase in MDA content. These results suggest that priming with L-methionine or CH would be better than HP for the protection of seedling root growth under salinity stress and might be associated with enhanced antioxidative defence against salinity-induced oxidative stress.

scholarly journals The key amino acids of E protein involved in early flavivirus infection: viral entry

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tao Hu ◽  
Zhen Wu ◽  
Shaoxiong Wu ◽  
Shun Chen ◽  
Anchun Cheng
Keyword(s):  
Amino Acids ◽  
Conformational Changes ◽  
Viral Entry ◽  
Envelope Protein ◽  
Cell Attachment ◽  
Envelope Proteins ◽  
Infection Process ◽  
Early Infection ◽  
Protein Amino Acids ◽  
Α Helix

AbstractFlaviviruses are enveloped viruses that infect multiple hosts. Envelope proteins are the outermost proteins in the structure of flaviviruses and mediate viral infection. Studies indicate that flaviviruses mainly use envelope proteins to bind to cell attachment receptors and endocytic receptors for the entry step. Here, we present current findings regarding key envelope protein amino acids that participate in the flavivirus early infection process. Among these sites, most are located in special positions of the protein structure, such as the α-helix in the stem region and the hinge region between domains I and II, motifs that potentially affect the interaction between different domains. Some of these sites are located in positions involved in conformational changes in envelope proteins. In summary, we summarize and discuss the key envelope protein residues that affect the entry process of flaviviruses, including the process of their discovery and the mechanisms that affect early infection.

Ileal digestibility of protein and amino acids of feed peas with different trypsin inhibitor activity in pigs

2000 ◽  
Vol 80 (4) ◽  
pp. 643-652 ◽  
Author(s):  
F. Grosjean ◽  
C. Jondreville ◽  
I. Williatte-Hazouard ◽  
F. Skiba ◽  
B. Carrouée ◽  
...  
Keyword(s):  
Amino Acids ◽  
Trypsin Inhibitor ◽  
Crude Protein ◽  
Trypsin Inhibitor Activity ◽  
Rectal Anastomosis ◽  
Inhibitor Activity ◽  
Ileal Digestibility ◽  
Physical Chemical ◽  
Protein Amino Acids ◽  
Weight Proportion

Ileal digestibility of protein and amino acids was measured in pigs fed 13 round, tannin-free peas samples and related to the following physical, chemical and biological characteristics of these samples: thousand-seed weight, proportion of hulls, starch, fibre, crude protein, ether extract and ash contents, trypsin inhibitor activity and trypsin inhibitor activity per unit of crude protein (TIAP). Each pea sample was included in a diet containing starch, sucrose, minerals and vitamins and fed to four barrows (50 to 100 kg) fitted with an end-to-end ileo-rectal anastomosis. Standardised ileal protein and amino acid digestibilities, except for alanine of peas decreased linearly with increasing TIAP (P < 0.01) and was not affected by fiber content. For example standardized ileal digestibilities values (%) decreased by −0.1975, −0.1617, −0.2171, −0.2630, −0.2029 and −0.3536 per unit of TIAP (expressed in unit of trypsin inhibited per milligram crude protein), respectively, for crude protein and lysine, threonine, methionine, cystine and tryptophan. Key words: Peas, trypsin inhibitor activity, standardised ileal digestibilities, protein, amino acids, pig

Free protein amino acids of some Mediterranean Siphonales

1984 ◽  
Vol 12 (1) ◽  
pp. 19-21
Author(s):  
Lorenzo de Napoli ◽  
Ernesto Fattorusso ◽  
Luciano Mayol ◽  
Ettore Novellino
Keyword(s):  
Amino Acids ◽  
Free Protein ◽  
Protein Amino Acids

scholarly journals BIOSYNTHESIS IN ISOLATED ACETABULARIA CHLOROPLASTS

1972 ◽  
Vol 54 (2) ◽  
pp. 279-294 ◽  
Author(s):  
David C. Shephard ◽  
Wendy B. Levin
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Technical Problems ◽  
Hydrolyzed Protein ◽  
Protein Amino Acids ◽  
Amino Acid Labeling ◽  
Labeling Pattern

The ability of chloroplasts isolated from Acetabulana mediterranea to synthesize the protein amino acids has been investigated. When this chloroplast isolate was presented with 14CO2 for periods of 6–8 hr, tracer was found in essentially all amino acid species of their hydrolyzed protein Phenylalanine labeling was not detected, probably due to technical problems, and hydroxyproline labeling was not tested for The incorporation of 14CO2 into the amino acids is driven by light and, as indicated by the amount of radioactivity lost during ninhydrin decarboxylation on the chromatograms, the amino acids appear to be uniformly labeled. The amino acid labeling pattern of the isolate is similar to that found in plastids labeled with 14CO2 in vivo. The chloroplast isolate did not utilize detectable amounts of externally supplied amino acids in light or, with added adenosine triphosphate (ATP), in darkness. It is concluded that these chloroplasts are a tight cytoplasmic compartment that is independent in supplying the amino acids used for its own protein synthesis. These results are discussed in terms of the role of contaminants in the observed synthesis, the "normalcy" of Acetabularia chloroplasts, the synthetic pathways for amino acids in plastids, and the implications of these observations for cell compartmentation and chloroplast autonomy.

Analysis of all protein amino acids as their tert.-butyldimethylsilyl derivatives by gas-liquid chromatography

1987 ◽  
Vol 163 (1) ◽  
pp. 175-181 ◽  
Author(s):  
Chin-Joo Goh ◽  
Kenneth G. Craven ◽  
James R. Lepock ◽  
Erwin B. Dumbroff
Keyword(s):  
Amino Acids ◽  
Liquid Chromatography ◽  
Gas Liquid Chromatography ◽  
Protein Amino Acids

Inter-annual and seasonal dynamics of amino acid, mineral and vitamin composition of silver belly Leiognathus splendens

2014 ◽  
Vol 95 (4) ◽  
pp. 817-828 ◽  
Author(s):  
Kajal Chakraborty ◽  
Deepu Joseph
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Content ◽  
West Coast ◽  
Sensor Data ◽  
The South ◽  
Post Monsoon ◽  
South West ◽  
South West Coast ◽  
Protein Amino Acids

Silver bellies, Leiognathus splendens were studied for their spatial (south-west and south-east coasts of India), annual (2008–2011) and seasonal (pre-monsoon, monsoon and post-monsoon) variations of protein, amino acids, vitamins and minerals. The monthly mean Sea Viewing Wide Field-of-view Sensor data for the period from January 2008 to December 2011 were taken into account to indicate the distribution of the photosynthetic pigment chlorophyll-a to test the hypothesis that surface productivity might be related to nutritional biochemistry of this species. The four year average total protein content and chlorophyll-a showed good correlation during monsoon on the south-west coast and monsoon/post-monsoon on the south-east coast, suggesting that the protein content is prejudiced by the chlorophyll-a concentration. Amino acid scores observed monsoon maxima along the south-west and south-east coasts. Significant seasonal variations in vitamin content were observed at the study locations with high content of vitamins D3, E, K1 and C on the south-west coast. Na content was maximal during pre-monsoon on the south-west coast, while post-monsoon maxima of Ca and K content were observed. The Fe, Mn and Zn were abundant in the samples collected from the south-west coast. The concentration of Se exhibited maximum values post-monsoon along the south-west and south-east coasts. The present study demonstrated L. splendens as a valuable source of the protein, amino acids, minerals and vitamins, showing that this low-value species is a good source of well balanced proteins with high biological value to be qualified as a preferred healthy food for human consumption.

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