scholarly journals Behavioral Responses of Phormia regina (Meigen) to Labellar Stimulation with Amino Acids

1973 ◽  
Vol 61 (1) ◽  
pp. 74-88 ◽  
Author(s):  
Nancy R. Goldrich

Behavioral responses to labellar stimulation with 19 L-amino acids were predicted on the basis of electrophysiological responses of largest labellar hairs. With the exceptions alanine, aspartic and glutamic acids, and valine tests of these predictions confirmed that Phormia can discriminate amino acids, and that these acids may be grouped according to their effects. Electrophysiological investigation of the four exceptions was repeated and results were consistent with the behavioral data. In particular, these acids elicited previously unreported responses from the salt receptor. The discrepancies between this and earlier studies may be explainable, in part, on methodological grounds. There was evidence for response differences among hairs of different sizes and among the largest labellar hairs themselves. The significance of amino acid discrimination for the problem of protein recognition can only be speculated upon until more complete electrophysiological and nutritional information is available.

1956 ◽  
Vol 34 (6) ◽  
pp. 527-532 ◽  
Author(s):  
Ernest Hodgson ◽  
Vernon H. Cheldelin ◽  
R. W. Newburgh

Phormia regina grown on a chemically defined diet under sterile conditions has been shown to have a specific dietary requirement for choline. The present work shows that carnitine and 2,2-dimethylaminoethanol can completely replace this in the diet whereas betaine is ineffective in this respect. Deletion of single amino acids from a mixture of 18 adequate for growth has previously shown the following 10 amino acids to be essential: arginine, histidine, leucine, lysine, phenylalanine, threonine, tryptophan, valine, proline, and isoleucine. The present work: shows by the inability of the organism to grow on these essential amino acids that this method is not adequate to detect amino acid combinations for which alternate requirements exist. By the deletion of groups of two or more amino acids it has been shown that P. regina has a dietary requirement for either methionine or cystine and for either glutamic acid or aspartic acid. Growth on the 10 essential amino acids is stimulated by yeast extract. This is apparently not due to a simple replacement of missing amino acids, since the addition of yeast creates an increased requirement for thiamine.


1972 ◽  
Vol 50 (6) ◽  
pp. 855-860 ◽  
Author(s):  
D. G. S. Wright ◽  
K. Ronald

Behavioral responses of miracidia of Schistosomatium douthitti to chemicals were tested using amino acids similar to those excreted by the schistosome intermediate host, Lymnaea palustris. Amino acids suspended in agar plugs were placed in one or more arms of a four-arm test chamber and responses of miracidia placed in the center well were recorded. Under optimum conditions (20C and 10 000 lux) 84% of the miracidia were found in side arms containing an amino acid mixture after 120 min. Miracidia moved towards glycine, leucine, and valine.The combined effects of amino acids and light on the response of miracidia were tested. After 120 min at 20C with illuminance from 4800 to 32 000 lux, 93 to 100% of the miracidia were found in side arms containing 0.83 μM/ml of amino acids exposed to light.


1970 ◽  
Vol 56 (6) ◽  
pp. 768-782 ◽  
Author(s):  
Akio Shiraishi ◽  
Mastaro Kuwabara

The effects of amino acids on the labellar hair chemosensory cells were examined with two kinds of flies (the fleshfly, Boettcherisca peregrina, and the blowfly, Phormia regina). As a result of this examination, the effects of amino acids were divided into four main classes. Amino acids in class 1 did not stimulate any chemoreceptor cell. Amino acids in class 2 inhibited nonspecifically the discharges from three kinds of chemosensory cells. Amino acids in class 3 stimulated the salt receptor cell. Amino acids in class 4 stimulated the sugar receptor cell. A possibility that a fourth neuron in the labellar hair chemosensory cell might be a protein or an amino acid receptor cell was eliminated.


Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.


1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.


1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.


2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.


Sign in / Sign up

Export Citation Format

Share Document