ESSENTIAL AMINO ACIDS IN MICROORGANISMS

1957 ◽  
Vol 3 (5) ◽  
pp. 721-728 ◽  
Author(s):  
F. Reusser ◽  
J. F. T. Spencer ◽  
H. R. Sallans

The cells of 19 species of bacteria, actinomyces, and yeasts were analyzed for protein and essential amino acids. A rapid quantitative method for amino acid determination using one-dimensional paper chromatography was developed. The cellular protein from all species contained relatively high concentrations of lysine, somewhat lower concentrations of tryptophan and threonine, and very low concentrations of methionine. All of the 10 essential amino acids were found in each species tested, although individual differences in the relative and absolute amounts were observed.

2015 ◽  
Vol 7 (18) ◽  
pp. 7574-7581 ◽  
Author(s):  
Magdalena M. Dziągwa-Becker ◽  
Jose M. Marin Ramos ◽  
Jakub K. Topolski ◽  
Wiesław A. Oleszek

Free amino acid determination in plants by LC-MS/MS.


1971 ◽  
Vol 121 (2) ◽  
pp. 197-202 ◽  
Author(s):  
M. E. Grant ◽  
F. S. Steven ◽  
D. S. Jackson ◽  
L. B. Sandberg

1. Insoluble elastin has been prepared by several different methods from adult bovine and calf ligamentum nuchae. Highly purified tropoelastin has been prepared from copper-deficient porcine aorta. 2. Amino acid analyses indicated that all preparations, except that obtained from calf ligamentum nuchae by using an EDTA extraction followed by collagenase digestion (preparation E6), were typical of pure elastin having high concentrations of hydrophobic and low concentrations of hydrophilic amino acids. Preparation E6 was found to contain approx. 40% collagen. 3. The determination and composition of the carbohydrates associated with these preparations is reported. With the exception of preparation E6, the insoluble elastins contained only trace amounts of neutral sugars (0.13–0.35%, w/w) and amino sugars (0.01–0.06%, w/w). The porcine tropoelastin contained virtually no carbohydrate. 4. The results suggest that carbohydrate analyses can yield valuable information about the purity of elastin preparations.


2021 ◽  
Author(s):  
Stephen J Fairweather ◽  
Esther Rajendran ◽  
Martin Blume ◽  
Kiran Javed ◽  
Birte Steinhoefel ◽  
...  

Intracellular parasites of the phylum Apicomplexa are dependent on the scavenging of essential amino acids from their hosts. We previously identified a large family of apicomplexan-specific plasma membrane-localized amino acid transporters, the ApiATs, and showed that the Toxoplasma gondii transporter TgApiAT1 functions in the selective uptake of arginine. TgApiAT1 is essential for parasite virulence, but dispensable for parasite growth in medium containing high concentrations of arginine, indicating the presence of at least one other arginine transporter. Here we identify TgApiAT6-1 as the second arginine transporter. Using a combination of parasite assays and heterologous characterisation of TgApiAT6-1 in Xenopus laevis oocytes, we demonstrate that TgApiAT6-1 is a general cationic amino acid transporter that mediates both the high-affinity uptake of lysine and the low-affinity uptake of arginine. TgApiAT6-1 is the primary lysine transporter in the disease-causing tachyzoite stage of T. gondii and is essential for parasite proliferation. We demonstrate that the uptake of cationic amino acids by TgApiAT6-1 is "trans-stimulated" by cationic and neutral amino acids and is likely promoted by an inwardly negative membrane potential. These findings demonstrate that T. gondii has evolved overlapping transport mechanisms for the uptake of essential cationic amino acids, and we draw together our findings into a comprehensive model that highlights the finely-tuned, regulated processes that mediate cationic amino acid scavenging by these intracellular parasites.


1982 ◽  
Vol 54 (4) ◽  
pp. 279-285
Author(s):  
Matti Näsi ◽  
Lea Huida

The apparent faecal digestibilities of amino acids were determined in growing pigs on diets in which 50% or 100 % soybean meal supplement was replaced by Eurolysine bacterial protein or Pekilo protein. The trial was conducted as two 3X3 Latin squares with six castrated pigs. Compared with the soybean meal supplement, the Eurolysine diet had lower (P < 0.05) digestibilities of arginine, leucine, methionine, phenylalanine and tyrosine. Compared with the Pekilo diet the Eurolysine diet had lower digestibilities (P < 0.05) of alanine, aspartic acid, glutamic acid, glycine, leucine, proline and serine. Lysine digestibility was higher on the Eurolysine diet than on the Pekilo diet. A gas chromatographic method used in amino acid determination is described and evaluated.


1971 ◽  
Vol 25 (2) ◽  
pp. 253-258 ◽  
Author(s):  
R. F. Grimble ◽  
R. G. Whitehead

1. The mechanisms by which an oral dose of glucose can stimulate the uptake of essential amino acids from serum was found to be operative even in children with severe, untreated kwashiorkor.2. Although the percentage fall in the concentration of the essential amino acids in response to glucose was the same before and after treatment, the absolute fall was greater on discharge. The results indicated that the magnitude of this fall might depend on the initial fasting concentration of each individual amino acid.3. These results have been discussed on the basis of possible long-term pathological effects of a distorted serum amino acid pattern typified by low concentrations of valine, leucine and threonine. The protein-sparing action of carbohydrate, achieved by the preferential synthesis of muscle protein in response to insulin secretion, might be less effective because of substrate limitation.4. Of the non-essential amino acids, the concentrations of alanine and glycine also fell markedly before treatment, but this did not occur on discharge. The significance of this difference is also discussed.5. The results also indicate that slightly high, spurious amino acid ratios can be obtained if a child is given a drink containing sugar before a blood sample is taken.


2021 ◽  
Vol 17 (8) ◽  
pp. e1009835
Author(s):  
Stephen J. Fairweather ◽  
Esther Rajendran ◽  
Martin Blume ◽  
Kiran Javed ◽  
Birte Steinhöfel ◽  
...  

Intracellular parasites of the phylum Apicomplexa are dependent on the scavenging of essential amino acids from their hosts. We previously identified a large family of apicomplexan-specific plasma membrane-localized amino acid transporters, the ApiATs, and showed that the Toxoplasma gondii transporter TgApiAT1 functions in the selective uptake of arginine. TgApiAT1 is essential for parasite virulence, but dispensable for parasite growth in medium containing high concentrations of arginine, indicating the presence of at least one other arginine transporter. Here we identify TgApiAT6-1 as the second arginine transporter. Using a combination of parasite assays and heterologous characterisation of TgApiAT6-1 in Xenopus laevis oocytes, we demonstrate that TgApiAT6-1 is a general cationic amino acid transporter that mediates both the high-affinity uptake of lysine and the low-affinity uptake of arginine. TgApiAT6-1 is the primary lysine transporter in the disease-causing tachyzoite stage of T. gondii and is essential for parasite proliferation. We demonstrate that the uptake of cationic amino acids by TgApiAT6-1 is ‘trans-stimulated’ by cationic and neutral amino acids and is likely promoted by an inwardly negative membrane potential. These findings demonstrate that T. gondii has evolved overlapping transport mechanisms for the uptake of essential cationic amino acids, and we draw together our findings into a comprehensive model that highlights the finely-tuned, regulated processes that mediate cationic amino acid scavenging by these intracellular parasites.


1973 ◽  
Vol 74 (2) ◽  
pp. 226-236 ◽  
Author(s):  
Michel Chrétien ◽  
Claude Gilardeau

ABSTRACT A protein isolated from ovine pituitary glands has been purified, and its homogeneity assessed by NH2- and COOH-terminal amino acid determination, ultracentrifugation studies, and polyacrylamide gel electrophoresis after carboxymethylation. Its chemical and immunochemical properties are closely similar to those of beef and pork neurophysins, less similar to those of human neurophysins. It contains no tryptophan (like other neurophysins) or histidine (like all except bovine neurophysin-I and human neurophysins). It has alanine at the NH2-terminus and valine at the COOH-terminus. Its amino acid composition is similar to, but not identical with those of porcine and bovine neurophysins.


2016 ◽  
Vol 5 (10) ◽  
pp. 4972
Author(s):  
Lata Birlangi

The date palm (Phoenix dactylifera L.) is one of mankind’s oldest cultivated plants. The fruit of the date palm is an important crop of the hot arid and semi-arid regions of the world. It has always played a genuine economic and social part in the lives of the people of these areas. The present objective in examining the amino acid content of different varieties of date palm fruits from Middle-East region; is to determine whether its protein could effectively supplement the nutritional value and it is also aimed in finding which variety is rich in number of amino acids. The phytochemical screening revealed the presence of eight essential amino acids and five non-essential amino acids in the date fruits. Among all the date fruit varieties taken as samples for the study, Dabbas cultivar of United Arab Emirates found to exhibit eight types of amino acids which includes five as non-essential ones. Total of thirteen amino acids were detected in the seven date cultivars. Determination of amino acid can serve as a guide to the possible nutritional value.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonia Yun Liu ◽  
Shemil P. Macelline ◽  
Peter V. Chrystal ◽  
Peter H. Selle

AbstractThe prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein (CP) diets and sustainable chicken-meat production may be best achieved. Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions; moreover, they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents. The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed. The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids. Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine, this emphasises the value of so-called “non-essential” amino acids. Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed, although the functions of insulin in avian species require clarification. Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets; if so, the identification of the underlying reasons for this difference should be instructive. Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance. Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance. If progress in these directions can be realised, then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.


EvoDevo ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Celeste R. Banfill ◽  
Alex C. C. Wilson ◽  
Hsiao-ling Lu

Abstract Background Host/symbiont integration is a signature of evolutionarily ancient, obligate endosymbioses. However, little is known about the cellular and developmental mechanisms of host/symbiont integration at the molecular level. Many insects possess obligate bacterial endosymbionts that provide essential nutrients. To advance understanding of the developmental and metabolic integration of hosts and endosymbionts, we track the localization of a non-essential amino acid transporter, ApNEAAT1, across asexual embryogenesis in the aphid, Acyrthosiphon pisum. Previous work in adult bacteriomes revealed that ApNEAAT1 functions to exchange non-essential amino acids at the A. pisum/Buchnera aphidicola symbiotic interface. Driven by amino acid concentration gradients, ApNEAAT1 moves proline, serine, and alanine from A. pisum to Buchnera and cysteine from Buchnera to A. pisum. Here, we test the hypothesis that ApNEAAT1 is localized to the symbiotic interface during asexual embryogenesis. Results During A. pisum asexual embryogenesis, ApNEAAT1 does not localize to the symbiotic interface. We observed ApNEAAT1 localization to the maternal follicular epithelium, the germline, and, in late-stage embryos, to anterior neural structures and insect immune cells (hemocytes). We predict that ApNEAAT1 provisions non-essential amino acids to developing oocytes and embryos, as well as to the brain and related neural structures. Additionally, ApNEAAT1 may perform roles related to host immunity. Conclusions Our work provides further evidence that the embryonic and adult bacteriomes of asexual A. pisum are not equivalent. Future research is needed to elucidate the developmental time point at which the bacteriome reaches maturity.


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