NUTRITION DES LARVES DE TRIBOLIUM CONFUSUM DUVAL: II. IMPORTANCE DES ACIDES AMINES

1951 ◽  
Vol 29 (2) ◽  
pp. 80-83 ◽  
Author(s):  
A. Lemonde ◽  
R. Bernard

The normal pupation period of Tribolium confusum on whole wheat diet averages 18 days. In presence of a purified diet containing 19 crystalline amino acids known to exist in casein, the pupation period is increased to 28 days. Removal of one of the amino acids considered as nonessential for growth in the rat from such a diet, results in pupation periods falling between 26 and 32 days. On the other hand, omission of lysine, threonine, phenylalanine, methionine, isoleucine, and arginine, one at a time, increases the pupation period from 61 to 70 days. If valine, tryptophane, histidine, or leucine are left out singly, pupation is prevented, though two-thirds of the larvae survive. It is concluded that the amino acids known to be essential for growth in the rat are also essential for growth and pupation of the larvae of T. confusum. Four of these essential amino acids appear to be connected with the phenomenon of pupation.

1948 ◽  
Vol 21 (4) ◽  
pp. 853-859
Author(s):  
R. F. A. Altman

Abstract As numerous investigators have shown, some of the nonrubber components of Hevea latex have a decided accelerating action on the process of vulcanization. A survey of the literature on this subject points to the validity of certain general facts. 1. Among the nonrubber components of latex which have been investigated, certain nitrogenous bases appear to be most important for accelerating the rate of vulcanization. 2. These nitrogen bases apparently occur partly naturally in fresh latex, and partly as the result of putrefaction, heating, and other decomposition processes. 3. The nitrogen bases naturally present in fresh latex at later stages have been identified by Altman to be trigonelline, stachhydrine, betonicine, choline, methylamine, trimethylamine, and ammonia. These bases are markedly active in vulcanization, as will be seen in the section on experimental results. 4. The nitrogenous substances formed by the decomposition processes have only partly been identified, on the one hand as tetra- and pentamethylene diamine and some amino acids, on the other hand as alkaloids, proline, diamino acids, etc. 5. It has been generally accepted that these nitrogenous substances are derived from the proteins of the latex. 6. Decomposition appears to be connected with the formation of a considerable amount of acids. 7. The production of volatile nitrogen bases as a rule accompanies the decomposition processes. These volatile products have not been identified. 8. The active nitrogen bases, either already formed or derived from complex nitrogenous substances, seem to be soluble in water but only slightly soluble in acetone.


1951 ◽  
Vol 29 (2) ◽  
pp. 71-79 ◽  
Author(s):  
A. Lemonde ◽  
R. Bernard

A purified diet suitable for the study of the qualitative amino acids requirements of the larvae of the Coleoptera Tribolium confusum is presented. The composition of the diet is as follows: amino acid mixture 20%, cornstarch 75.5%, cholesterol 1%, wheat germ oil 1.5%, salt mixture No. 2 U.S.P. XII 2%, yeast 0.5%, vitamin mixture M.V.–II. In presence of amino acids, glucose cannot be used as a source of hydrocarbon. The mixture is very hygroscopic, develops a brown color, and is apparently toxic to the larvae. The importance of choline as a growth factor is demonstrated. Wilson's Liver Fraction L or Liver Concentrate 1: 20 cannot replace this vitamin. Yeast appears to contain unknown factors for it improves growth when added to a diet already supplemented with vitamins known to be essential for the larvae. A mixture of 19 crystalline amino acids known to occur in casein satisfies the nitrogen requirements of the larvae of T. confusum equally as well as purified casein.


2011 ◽  
Vol 29 (No. 4) ◽  
pp. 373-381 ◽  
Author(s):  
J. Horníčková ◽  
R. Kubec ◽  
J. Velíšek ◽  
CejpekK ◽  
J. Ovesná ◽  
...  

The contents of three S-alk(en)ylcysteine sulfoxides (alliin, methiin, and isoalliin) were determined in the leaves, pseudostems, and bulbs of six garlic genotypes (two flowering plant morphotypes, two semi bolters, and two scape absent morphotypes) cultivated for five consecutive years at the same location. The average levels of alliin, methiin, and isoalliin were found to be as follows: 1.92, 0.44, and 0.07 mg/g fw in the leaves, 1.57, 0.27, and 0.08 mg/g fw in the pseudostems, and 1.71, 0.20 and 0.13 mg/g fw in the bulbs, respectively. No statistically significant year-to-year differences were observed between the samples. Furthermore, the total contents and relative proportions of S-alk(en)ylcysteine sulfoxides in various parts of the plants (leaves, pseudostems, bulbs and roots) were evaluated in detail during the whole vegetation period. It was observed that the total content of these amino acids gradually decreased in all parts except for the bulbs. In the bulbs, the total content initially decreased after planting but significantly increased in June and culminated before harvest. Analogous trends were also observed for alliin and methiin concentrations. On the other hand, isoalliin levels steadily decreased during the whole vegetation period in all parts of the plants.


1964 ◽  
Vol 42 (6) ◽  
pp. 757-762
Author(s):  
J. Leblanc ◽  
J. L. Villeneuve ◽  
A. Lemonde

Aminoguanidine, a histaminase inhibitor, was found to increase fecundity of Tribolium confusum (Coleoptera) when added as a supplement to the basal diet in concentrations of 0.01 and 0.5%. On the other hand alpha-methyl dopa, a decarboxylase inhibitor, had no effect on larval development except at a concentration of 1% where it was shown to be highly toxic. No catechol amines were found in adults of this species, but histamine was always detected and reached higher levels in insects fed higher concentrations of aminoguanidine. These results suggest a possible role for histamine in insect reproduction.


2001 ◽  
Vol 276 (15) ◽  
pp. 11705-11711 ◽  
Author(s):  
Jan B. Koenderink ◽  
Herman G. P. Swarts ◽  
H. Christiaan Stronks ◽  
Harm P. H. Hermsen ◽  
Peter H. G. M. Willems ◽  
...  

In this study we reveal regions of Na+,K+-ATPase and H+,K+-ATPase that are involved in cation selectivity. A chimeric enzyme in which transmembrane hairpin M5-M6 of H+,K+-ATPase was replaced by that of Na+,K+-ATPase was phosphorylated in the absence of Na+and showed no K+-dependent reactions. Next, the part originating from Na+,K+-ATPase was gradually increased in the N-terminal direction. We demonstrate that chimera HN16, containing the transmembrane segments one to six and intermediate loops of Na+,K+-ATPase, harbors the amino acids responsible for Na+specificity. Compared with Na+,K+-ATPase, this chimera displayed a similar apparent Na+affinity, a lower apparent K+affinity, a higher apparent ATP affinity, and a lower apparent vanadate affinity in the ATPase reaction. This indicates that theE2K form of this chimera is less stable than that of Na+,K+-ATPase, suggesting that it, like H+,K+-ATPase, de-occludes K+ions very rapidly. Comparison of the structures of these chimeras with those of the parent enzymes suggests that the C-terminal 187 amino acids and the β-subunit are involved in K+occlusion. Accordingly, chimera HN16 is not only a chimeric enzyme in structure, but also in function. On one hand it possesses the Na+-stimulated ATPase reaction of Na+,K+-ATPase, while on the other hand it has the K+occlusion properties of H+,K+-ATPase.


1945 ◽  
Vol 81 (5) ◽  
pp. 439-448 ◽  
Author(s):  
S. C. Madden ◽  
R. R. Woods ◽  
F. W. Shull ◽  
J. H. Remington ◽  
G. H. Whipple

Several synthetic mixtures of natural and racemic crystalline amino acids suitable for the daily nitrogen requirement are tested in dogs for their tolerance upon intravenous injection. Certain mixtures of the ten essential amino acids plus non-essential amino acids exclusive of glutamic acid are accepted without any obvious sign of disturbance even at rates above 10 mg. nitrogen per kilo per minute for quantities greater than 300 mg. per kilo. One such mixture consists in parts per 100 of dl-threonine 7, dl-valine 15, l(-)-leucine 10.9, dl-isoleucine 9.9, l(+)-lysine· HCl·H2O 10.9, dl-tryptophane 3, dl-phenylalanine 9.9, dl-methionine 6, l(+)-histidine·HCl·H2O 5, l(+)-arginine-HCl 5, glycine 9.9, dl-α-alanine 4, dl-serine 2, l(-)-cystine 0.5, and l(-)-tyrosine 1. In addition other well tolerated mixtures included the prolines. When glutamic acid, natural or racemic, is included in similar mixtures vomiting reactions frequently occur at nitrogen rates above 4 mg. per kilo per minute. Vomiting almost always occurs on the first daily injection containing glutamic acid and usually on any subsequent injection containing more than 100 mg. glutamic acid per kilo unless given very slowly. Upon the addition of glycine certain mixtures of the ten essential amino acids show an improved tolerance. Two casein digests tested usually produced vomiting at injection rates above 2 mg. nitrogen per kilo per minute, probably because of their glutamic acid content. No serious reaction has ever occurrred to any mixture of amino acids or casein digest tested. Elimination of minor reactions such as vomiting appears possible and desirable for greater usefulness of these solutions in parenteral feeding.


2007 ◽  
Vol 277 ◽  
pp. 1-3 ◽  

In a nutshellExercise increases oxidation of amino acids such as leucine.On the other hand, leucine is a powerful mediator of protein synthesis in muscle, promoting improved function, reduced fatigue and enhanced recovery from exertion. There is RCT evidence that leucine improves sports performance, particularly for endurance activity, but more evidence is still needed.


1933 ◽  
Vol 5 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Samuel Morris ◽  
Norman C. Wright

The results of the present experiments and of those reported in the previous paper(1) may be summarised as follows:1. When minimal quantities of protein are fed in the production rations of milking cows, a deficiency of either lysine or tryptophane will lead to a marked reduction in milk yield. There is, however, some evidence of the storage of reserve N, which can be utilised when the food protein is inadequate.2. The feeding of a lysine- or tryptophane-deficient ration causes a marked increase in urinary N, indicating a poor utilisation of food protein. On the other hand, the feeding of a ration containing adequate quantities of these essential amino acids reduces the urinary N, indicating efficient protein utilisation.3. The utilisation of body tissue in an attempt to maintain normal milk production on a deficient protein ration is shown by the high creatine excretion. The fact that the S: N ratio of the excess sulphur and nitrogen excreted during the deficient protein periods approximates that of body tissue (circa 1: 15·7) confirms this conclusion.


2021 ◽  
Vol 8 (11) ◽  
Author(s):  
Mazarin Akami ◽  
Ousman Tamgue ◽  
Xueming Ren ◽  
Yaohui Wang ◽  
Xuewei Qi ◽  
...  

In order to understand the role of symbionts for their insect hosts, it is customary to treat them with antibiotics or to sterilize eggs (treatments), resulting in aposymbiotic and axenic insects, respectively. Such axenic insects can then be compared with untreated controls. Fruit flies often bear complex communities which are greatly reduced by such treatments. However, the bacterial community is not completely eliminated. Here, we examine the effect of these procedures on the structure of the remaining bacterial communities in Bactrocera dorsalis (Diptera: Tephritidae) and on the insect longevity. The antibiotics (Norfloxacin and Ceftazedime) were administered to 1-day-old adult flies through sugar meal for 7 days, and eggs were surface sterilized and dechorionated to produce axenic lines. The flies were starved of protein before they were offered full diets or diets containing non-essential amino acids only. Antibiotic and egg disinfection treatments resulted in a significant reduction of the vast majority of gut bacterial populations, especially Proteobacteria, Firmicutes and Bacteroidetes. On the other hand, antibiotic allowed the persistence of Actinobacteria, Cyanobacteria and Acidobacteria populations. In untreated control flies, longevity was extended irrespective of diet quality in comparison to treated flies. Conversely, when gut bacteria were largely reduced (aposymbiotic and axenic flies), longevity was reduced in the non-essential amino acids diet treatment versus slightly improved in the presence of a protein diet. We discuss these results in an ecological–life-history perspective.


Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7485
Author(s):  
Kyung-Hyun Cho

α-synuclein (α-syn) is a major culprit of Parkinson’s disease (PD), although lipoprotein metabolism is very important in the pathogenesis of PD. α-syn was expressed and purified using the pET30a expression vector from an E. coli expression system to elucidate the physiological effects of α-syn on lipoprotein metabolism. The human α-syn protein (140 amino acids) with His-tag (8 amino acids) was expressed and purified to at least 95% purity. Isoelectric focusing gel electrophoresis showed that the isoelectric point (pI) of α-syn and apoA-I were pI = 4.5 and pI = 6.4, respectively. The lipid-free α-syn showed almost no phospholipid-binding ability, while apoA-I showed rapid binding ability with a half-time (T1/2) = 8 ± 0.7 min. The α-syn and apoA-I could be incorporated into the reconstituted HDL (rHDL, molar ratio 95:5:1:1, palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC):cholesterol:apoA-I:α-syn with the production of larger particles (92 Å) than apoA-I-rHDL (86 and 78 Å) and α-syn-rHDL (65 Å). An rHDL containing both apoA-I and α-syn showed lower α-helicity around 45% with a red shift of the Trp wavelength maximum fluorescence (WMF) from 339 nm, while apoA-I-HDL showed 76% α-helicity and 337 nm of WMF. The denaturation by urea addition showed that the incorporation of α-syn in rHDL caused a larger increase in the WMF than apoA-I-rHDL, suggesting that the destabilization of the secondary structure of apoA-I by the addition of α-syn. On the other hand, the addition of α-syn induced two-times higher resistance to rHDL glycation at apoA-I:α-syn molar ratios of 1:1 and 1:2. Interestingly, low α-syn in rHDL concentrations, molar ratio of 1:0.5 (apoA-I:α-syn), did not prevent glycation with more multimerization of apoA-I. In the lipid-free and lipid-bound state, α-syn showed more potent antioxidant activity than apoA-I against cupric ion-mediated LDL oxidation. On the other hand, microinjection of α-syn (final 2 μM) resulted in 10% less survival of zebrafish embryos than apoA-I. A subcutaneous injection of α-syn (final 34 μM) resulted in less tail fin regeneration than apoA-I. Interestingly, incorporation of α-syn at a low molar ratio (apoA-I:α-syn, 1:0.5) in rHDL resulted destabilization of the secondary structure and impairment of apoA-I functionality via more oxidation and glycation. However, at a higher molar ratio of α-syn in rHDL (apoA-I:α-syn = 1:1 or 1:2) exhibited potent antioxidant and anti-glycation activity without aggregation. In conclusion, there might be a critical concentration of α-syn and apoA-I in HDL-like complex to prevent the aggregation of apoA-I via structural and functional enhancement.


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