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91.
Results in this study are consistent with those of Murdock and his colleagues who clearly demonstrated that clonidine, an agonist of octopaminergic receptors in some insects, significantly increases sucrose feeding. Their studies, however, did not examine the effect of clonidine on protein feeding. Injection of a 20 microg/microl/fly dose of clonidine significantly reduces protein feeding in both sexes of Phormia regina, instead of stimulating feeding as is observed with carbohydrate feeding. The manner in which the flies are fed prior to starvation and the method of testing influences the amounts of diet consumed. It is proposed that the biogenic amines influence the state of hunger (i.e., protein versus carbohydrates) while other chemicals and neural mechanisms (i.e., such as sulfakinins and stretch receptors, respectively) affect satiety. 相似文献
92.
To determine the salivary secretory immunoglobulin A (sIgA) response to repeated bouts of unaccustomed, downhill running (eccentrically biased) and examine potential protective immunological adaption from a repeated bout effect. Eleven active but untrained males (age: 19.7±0.4 years; VO2peak: 47.8± 3.6 ml · kg−1 · min −1) performed two 60 min bouts (Run 1 and Run 2) of downhill running (−13.5% gradient), separated by 14 days, at a speed eliciting 75% of their VO2peak on a level grade. Saliva samples were collected before (baseline), immediately post exercise (IPE), and every hour for 12 h and every 24 h for 6 days after each run. Salivary sIgA concentration was measured and sIgA secretion rate was calculated. Results were analysed using repeated measures ANOVA (12 h period: 2x14; 24 h intervals: 2x7; p ≤ 0.05) with Tukey post-hoc tests where appropriate. Results are reported as means ± SE. There was a significant (p < 0.0001) interaction effect for sIgA secretion rate, IPE, with higher values after Run 2, as well as a significant (p < 0.01) time effect with elevated levels IPE and between 24 h and 144 h. There was a run effect (p < 0.0001), with the sIgA secretion rate significantly higher after Run 2. Repeated bouts of unaccustomed, eccentrically biased exercise induced alterations in the salivary sIgA secretion rate. This may serve as a protective mucosal adaptation to exercise-induced tissue damage. 相似文献
93.
Genes essential for the production of a linear, bacterial (1-->3)-beta-
glucan, curdlan, have been cloned for the first time from Agrobacterium sp.
ATCC31749. The genes occurred in two, nonoverlapping, genomic fragments
that complemented different sets of curdlan( crd )-deficient
transposon-insertion mutations. These were detected as colonies that failed
to stain with aniline blue, a (1-->3)-beta-glucan specific dye. One
fragment carried a biosynthetic gene cluster (locus I) containing the
putative curdlan synthase gene, crdS, and at least two other crd genes. The
second fragment may contain only a single crd gene (locus II).
Determination of the DNA sequence adjacent to several locus I mutations
revealed homology to known sequences only in the cases of crdS mutations.
Complete sequencing of the 1623 bp crdS gene revealed highest similarities
between the predicted CrdS protein (540 amino acids) and glycosyl
transferases with repetitive action patterns. These include bacterial
cellulose synthases (and their homologs), which form
(1-->4)-beta-glucans. No similarity was detected with putative
(1-->3)- beta-glucan synthases from yeasts and filamentous fungi.
Whatever the determinants of the linkage specificity of these beta-glucan
synthases might be, these results raise the possibility that
(1-->3)-beta-glucans and (1-->4)-beta-glucans are formed by related
catalytic polypeptides.
相似文献
94.
Greg J Poet Ojore BV Oka Marcel van Lith Zhenbo Cao Philip J Robinson Marie Anne Pringle Elias SJ Arnér Neil J Bulleid 《The EMBO journal》2017,36(5):693-702
Folding of proteins entering the secretory pathway in mammalian cells frequently requires the insertion of disulfide bonds. Disulfide insertion can result in covalent linkages found in the native structure as well as those that are not, so‐called non‐native disulfides. The pathways for disulfide formation are well characterized, but our understanding of how non‐native disulfides are reduced so that the correct or native disulfides can form is poor. Here, we use a novel assay to demonstrate that the reduction in non‐native disulfides requires NADPH as the ultimate electron donor, and a robust cytosolic thioredoxin system, driven by thioredoxin reductase 1 (TrxR1 or TXNRD1). Inhibition of this reductive pathway prevents the correct folding and secretion of proteins that are known to form non‐native disulfides during their folding. Hence, we have shown for the first time that mammalian cells have a pathway for transferring reducing equivalents from the cytosol to the ER, which is required to ensure correct disulfide formation in proteins entering the secretory pathway. 相似文献
95.
96.
97.
Hydrogen exchange studies of rhodopsin in disc membranes demonstrated that photolysis induces changes in the protein itself. Two different altered forms were detected. A late photointermediate in the bleaching sequence, which can be identified with metarhodopsin II, displays accelerated exchange. Subsequently, at the stage of fully bleached opsin, exchange becomes even slower than in rhodopsin. These changes involve only a small fraction of the protein's internally hydrogen-bonded peptide groups. The unusually large fraction of exposed peptide hydrogens observed previously for rhodopsin is unaltered in the photolyzed forms. 相似文献
98.
Background
Combining data from different ethnic populations in a study can increase efficacy of methods designed to identify expression quantitative trait loci (eQTL) compared to analyzing each population independently. In such studies, however, the genetic diversity of minor allele frequencies among populations has rarely been taken into account. Due to the fact that allele frequency diversity and population-level expression differences are present in populations, a consensus regarding the optimal statistical approach for analysis of eQTL in data combining different populations remains inconclusive. 相似文献99.
Molecular Ecology Resources Primer Development Consortium Anderson CM Aparicio GJ Atangana AR Beaulieu J Bruford MW Cain F Campos T Cariani A Carvalho MA Chen N Chen PP Clamens AL Clark AM Coeur D'Acier A Connolly P Cordero-Rivera A Coughlan JP Cross TS David B DE Bruyn C DE Meyer M DE Ridder C Delatte H Dettori MT Downer SJ Dubreuil C Evans KJ Fan B Ferrara G Gagné A Gaillard M Gigliarelli L Giovinazzi J Gomez DR Grünwald NJ Hansson B Huotari T Jank L Jousselin E Jungmann L Kaczmarek ME 《Molecular ecology resources》2010,10(3):576-579
This article documents the addition of 220 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Allanblackia floribunda, Amblyraja radiata, Bactrocera cucurbitae, Brachycaudus helichrysi, Calopogonium mucunoides, Dissodactylus primitivus, Elodea canadensis, Ephydatia fluviatilis, Galapaganus howdenae howdenae, Hoplostethus atlanticus, Ischnura elegans, Larimichthys polyactis, Opheodrys vernalis, Pelteobagrus fulvidraco, Phragmidium violaceum, Pistacia vera, and Thunnus thynnus. These loci were cross-tested on the following species: Allanblackia gabonensis, Allanblackia stanerana, Neoceratitis cyanescens, Dacus ciliatus, Dacus demmerezi, Bactrocera zonata, Ceratitis capitata, Ceratitis rosa, Ceratits catoirii, Dacus punctatifrons, Ephydatia mülleri, Spongilla lacustris, Geodia cydonium, Axinella sp., Ischnura graellsii, Ischnura ramburii, Ischnura pumilio, Pistacia integerrima and Pistacia terebinthus. 相似文献
100.
C Nageswara Raju S Sailaja S Pavan Kumari SJ Dhoble V Ramesh Kumar MV Ramanaiah B Sudhakar Reddy 《Luminescence》2013,28(2):162-168
This article reports on the optical properties of 0.5% mol of Sm3+, Dy3+ ion‐doped B2O3‐TeO2‐Li2O‐AlF3 (LiAlFBT) glasses. The glass samples were characterized by optical absorption and emission spectra. Judd‐Ofelt theory was applied to analyze the optical absorption spectra and calculate the intensity parameters and radiative properties of the emission transitions. The emission spectra of Sm3+ and Dy3+:LiAlFBT glasses showed a bright reddish‐orange emission at 598 nm (4G5/2 → 6H7/2) and an intense yellow emission at 574 nm (4F9/2 → 6H13/2), respectively. Full width at half maximum (FWHM), stimulated emission cross section, gain bandwidth and optical gain values were also calculated to extend the applications of the Sm3+ and Dy3+:LiAlFBT glasses. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献