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1.
A subgroup-specific antigenic site in the G protein of respiratory syncytial virus forms a disulfide-bonded loop. 下载免费PDF全文
B Akerlind-Stopner G Utter M A Mufson C Orvell R A Lerner E Norrby 《Journal of virology》1990,64(10):5143-5148
An antigenic site (represented by 15 amino acids, residues 174 to 188, designated peptide 12) of the large glycoprotein G of respiratory syncytial virus was demonstrated to be subgroup specific in peptide enzyme-linked immunosorbent assay tests with murine monoclonal antibodies and human postinfection sera. The role of individual amino acids in this subgroup-specific site was determined by use of single-amino-acid-deletion sets of peptides. When monoclonal antibodies were reacted with the deletion sets, a broad amino acid dependence of 11 or 12 residues, Cys-176 (Ile-175 in subgroup B) to Cys-186, was found. Human postinfection sera exhibited a narrower reaction profile (for subgroup A, Cys-182 to Trp-183; for subgroup B, Cys-176 to Lys-183). Reduction of peptides on microtiter plates by treatment with dithiothreitol completely destroyed their antigenic activity in tests with monoclonal antibodies and human postinfection sera of subgroup B. A variant of peptide 12 containing all four cysteines of the G protein (represented by 16 amino acids, residues 172 to 187, designated peptide 12var) also was subgroup specific. We concluded that the activity of the antigenic site in tests with monoclonal antibodies for subgroups A and B appears to depend on intrapeptide disulfide bonds. Reactions with postinfection sera of subgroup B also may depend on a disulfide bond. In contrast, postinfection sera of subgroup A appeared to have the capacity to identify a subgroup-specific site in a linear form of the selected 15-amino-acid-long peptide. Treatment of peptides with dithiothreitol had no effect on their antigenic activity in tests with human postinfection sera of subgroup A. These findings have relevance for molecular engineering of peptide antigens for use in respiratory syncytial virus subgroup-specific site-directed serology. 相似文献
2.
Carbohydrate and the cytokine response to 2.5h of running 总被引:10,自引:0,他引:10
Nehlsen-Cannarella S. L.; Fagoaga O. R.; Nieman D. C.; Henson D. A.; Butterworth D. E.; Schmitt R. L.; Bailey E. M.; Warren B. J.; Utter A.; Davis J. M. 《Journal of applied physiology》1997,82(5):1662-1667
Nehlsen-Cannarella, S. L., O. R. Fagoaga, D. C. Nieman, D. A. Henson, D. E. Butterworth, R. L. Schmitt, E. M. Bailey, B. J. Warren, A. Utter, and J. M. Davis. Carbohydrate and the cytokineresponse to 2.5 h of running. J. Appl.Physiol. 82(5): 1662-1667, 1997.This randomized,double-blind, placebo-controlled study was designed to determine theinfluence of 6% carbohydrate (C) vs. placebo (P) beverage ingestion oncytokine responses (5 total samples over 9 h) to 2.5 h ofhigh-intensity running (76.7 ± 0.4% maximalO2 uptake) by 30 experiencedmarathon runners. For interleukin-6 (IL-6), a difference in the patternof change between groups was found, highlighted by a greater increasein P vs. C immediately postrun (753 vs. 421%) and 1.5 h postrun (193 vs. 86%) [F(4,112) = 3.77, P = 0.006]. Forinterleukin-1-receptor antagonist (IL-1ra), a difference in the patternof change between groups was found, highlighted by a greater increasein P vs. C 1.5 h postrun (231 vs. 72%)[F(2,50) = 6.38, P = 0.003]. No significant interaction effects were seen for bioactive IL-6 or IL-1. The immediate postrun plasma glucose concentrations correlated negatively with those of plasma cortisol (r = 0.67, P < 0.001); postrun plasma cortisol (r = 0.70, P < 0.001) and IL-6 levels(r = 0.54, P = 0.003) correlated positively withlevels of IL-1ra. Taken together, the data indicate that carbohydrateingestion attenuates cytokine levels in the inflammatory cascade inresponse to heavy exertion. 相似文献
3.
Physical-chemical studies of pyruvate carboxylase from Pseudomonas citronellolis demonstrate that the enzyme has an alpha 4 beta 4 structure. The individual polypeptides, alpha (Mr = 65,000) and beta (Mr = 54,000), were separated and isolated by preparative gel electrophoresis. Analysis of the relationship between Coomassie blue staining and protein quantity for each polypeptide indicated that the alpha and beta subunits are present in a 1:1 stoichiometry in the native enzyme. Determinations of the molecular weight of the protein by sedimentation equilibrium (Mr = 454,000), gel filtration analysis (Mr = 510,000), disc gel electrophoresis (Mr = 530,000), and mass measurement from the Scanning Transmission Electron Microscope (Mr = 530,000) are consistent with the proposed alpha 4 beta 4 structure. Disc gel electrophoresis studies revealed that under certain circumstances the enzyme may dissociate to a smaller molecular weight species (Mr = 228,000). This dissociation phenomenon could explain the earlier reported observation of Taylor et al. ((1972) J. Biol. Chem 22, 7388-8390) that the enzyme had a molecular weight of 265,000. Evidence from electron microscopic studies shows that the three-dimensional structure of this enzyme is quite distinct from other species of pyruvate carboxylase. The enzyme does not show the typical rhombic appearance which has been noted for chicken liver, sheep liver, and yeast pyruvate carboxylase. 相似文献
4.
Use of avidin-sepharose to isolate and idenify biotin polypeptides from crude extracts 总被引:4,自引:0,他引:4
A method of isolating and identifying biotin polypeptides from crude cellular extracts is described. Protein samples are run on small avidin-Sepharose columns. After washing away nonspecifically bound protein, the biotin enzymes are eluted using an SDS-urea solution. The inactive polypeptides are then electrophoresed on SDS-polyacrylamide gels. The biotin polypeptides in the gels are identified by using fluorescent avidin or by analyzing for radioactive biotin-labeled polypeptides. A sensitive method for assaying biotin using avidin-Sepharose is also described. 相似文献
5.
Given over 90 combined years in academic and professional activities related to genetics and fishery management (FU 57, JS 36—see Waples et al. 2008 ), we are pleased to provide an invited perspective generated by the interesting and useful article of McCusker & Bentzen (2010) . These authors reaffirm the apparent signature of neutrality of mitochondrial and microsatellite markers through an exhaustive analysis of archived genotypic data for 105 marine and freshwater fishes. They note that their conclusions are consistent with earlier and less comprehensive analyses and that they do not exclude the operation of some selective activity (e.g. genetic ‘draft’), which may be overwhelmed by Ne‐related stochastic processes. Here, we provide a complementary focus, recalling relevant issues related to neutrality and selection in applications of molecular variations in fishery management. 相似文献
6.
Numerical simulation of saccular aneurysm hemodynamics: influence of morphology on rupture risk 总被引:1,自引:0,他引:1
The governing equations for pulsatile fluid flow were solved in their finite volume formulation in order to simulate blood flow in a variety of three-dimensional aneurysm geometries. The influence of geometric factors on flow patterns and fluid mechanical forces was studied with the goal of identifying the risk of aneurysm rupture. Aneurysm morphology was characterized by quantitative shape indices reflecting the three dimensionality of the vasculature derived from clinical studies. Recirculation zones and secondary flows were observed in aneurysms and arteries. Regions of extreme and alternating shear stress were observed and identified as sites for potential aneurysm rupture. The ellipticity of an aneurysm was observed to be strongly correlated with wall shear stress at the aneurysm fundus, while its non-sphericity, volume, and degree of undulation were more weakly correlated. 相似文献
7.
Dumke CL McBride JM Nieman DC Gowin WD Utter AC McAnulty SR 《Journal of strength and conditioning research / National Strength & Conditioning Association》2007,21(4):1214-1219
The purpose of this investigation was to determine the effects of 2.5 hours of cycling with and without carbohydrate supplementation on gross efficiency (GE). Trained cyclists (N = 15) were tested for V(.-)O2max (53.6 + 2.2 ml x kg(-1) x min(-1)) and lactate threshold during incremental tests to exhaustion. On 2 separate visits, cyclists performed 2.5 hours of cycling on an indoor trainer. A carbohydrate (C) or placebo (P) beverage was randomly provided and counterbalanced for each of the trials. Gross efficiency, cycling economy, power output, V(.-)O2, lactate, and blood glucose were measured every 20 minutes during the 2.5-hour ride. Muscle glycogen was measured immediately before and after the ride from the vastus lateralis. Results indicated that power output and V(.-)O2 decreased over time (p < 0.05) but were not different between trials. Relative GE and cycling economy during C were greater than P at 40 and 150 minutes (p < 0.05). Blood glucose significantly decreased in P and was lower than C at all time points (p < 0.05). Respiratory exchange ratio decreased over time in both trials, with a significant treatment effect at 40 and 150 minutes (p < 0.05). Muscle glycogen decreased by 65% during both conditions (p < 0.05) but demonstrated no treatment effect. We conclude that carbohydrate supplementation during 2.5 hours of cycling attenuated the decrease in GE possibly by maintaining blood glucose levels. This suggests that the positive effect of carbohydrate supplementation on endurance performance may be through the maintenance of metabolic efficiency. 相似文献
8.
Melinda D. Chambers Glenn R. VanBlaricom Fred Utter 《Journal of experimental marine biology and ecology》2006,331(2):173-185
The genetic structure of black abalone populations in the southern California Islands and central California coast was investigated by protein electrophoresis. Detailed sampling of San Nicolas Island (SN) permitted investigation of microgeographic genetic differentiation among local geomorphological features. In addition, temporal genetic differentiation was assessed by comparing juveniles and adults at three islands, San Miguel (SM), Santa Cruz (SC) and San Nicolas (SN). Mainland and island locations were genetically differentiated based on allele frequency differences and the presence of private alleles in some island populations. Although microgeographic genetic structure among sites on SN was weak and not statistically significant, heterozygosity varied among sites, with diversity decreasing from west to east. In addition, investigation among cohorts showed that adults were genetically differentiated among island locations, whereas no differences among juveniles were detected. Genetic differentiation between adult and juvenile abalones was detected at SC but not SM or SN. These data are generally consistent with local recruitment augmented by relatively more gene flow among island populations than among island and mainland populations, and possible selection acting on immigrant recruits. 相似文献
9.
Utter AC McAnulty SR Riha BF Pratt BA Grose JM 《Journal of strength and conditioning research / National Strength & Conditioning Association》2012,26(1):9-15
The objective of this study was to examine the validity of multifrequency direct segmental bioelectrical impedance analysis (DSM-BIA) measures to detect changes in the hydration status of wrestlers after they underwent 3% acute dehydration and a 2-hour rehydration period. Fifty-six National Collegiate Athletic Association wrestlers: (mean ± SEM); age 19.5 ± 0.2 years, height 1.73 ± 0.01 m, and body mass (BM) 82.5 ± 2.3 kg were tested in euhydrated, dehydrated (-3.5%), and 2-hour rehydration conditions using DSM-BIA to detect the changes in hydration status. The hydration status was quantified by measuring the changes in plasma osmolality (P(osm)), urine osmolality (Uosm), urine specific gravity (U(sg)), BM, and weighted segmental impedance at frequencies of 5, 20, 50, 100, and 500 kHz. Weighted segmental impedance significantly increased after a 3.5% reduction in the body weight for all the 5 frequencies evaluated, but it did not return to baseline at 2-hour rehydration. P(osm) (303 ± 0.6 mOsm·L(-1)), Uosm (617 ± 47 mOsm·L(-1)), and U(sg) (1.017 ± 0.001) all significantly increased at postdehydration and returned to baseline at 2-hour rehydration. Estimations of extracellular water were significantly different throughout the trial, but there were no significant changes in the estimations of the total body water or intracellular water. The results of this study demonstrate the potential use of DSM-BIA as a field measure to assess the hydration status of wrestlers for the purpose of minimal weight certification before the competitive season. When employing DSM-BIA to assess the hydration status, the results indicated that the changes in weighted segmental impedance at the frequencies evaluated (5, 20, 50, 100, and 500 kHz) are sensitive to acute changes in dehydration but lag behind changes in the standard physiological (plasma and urinary) markers of hydration status after a 2-hour rehydration period. 相似文献
10.