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This study used monoclonal antibodies to sheep MHC class II molecules as well as an L cell transfectant (T8.1) which expresses DRA and DRB genes to show that two distinct DRβ chains are expressed in the sheep. Two anti-β chain specific monoclonal antibodies VPM37 and VPM43 react with DR antigen but not DQ antigen by ELISA. These two antibodies do not react with the DRβ chain expressed in the T8.1 cell line. Two-dimensional immunoblotting shows that these antibodies recognize a subgroup of the spots recognized by the DR-specific monoclonal antibody VPM57 which does react with the T8.1 β chain. Amino-terminal sequence analysis of the α chain associated with VPM37β chain shows that this α chain is homologous to the human DRα chain strongly indicating that the β chain is DR-like. VPM37 and VPM43 are shown to be directed against different epitopes on sheep MHC class II molecules so it is highly unlikely that the data can be explained by the presence of posttranslational modifications or the existence of a very common allele. These data provide clear evidence for the expression of two distinct DRP chains in the sheep. 相似文献
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Evidence from morphology and anatomy (including embryology), as well as from palynology, chemistry and cytology, indicates
thatHydrastis is quite divergent from Ranunculaceae (in which the genus has been most often included) as well as from both Glaucidiaceae
and Berberidaceae. Distinctive features ofHydrastis, which demarcate it from Ranunculaceae but which are sometimes shared by Berberidaceae, are: the unique mode of origin of
the vascular supply to stamens and carpels; the micropyle being formed by both integuments; the xylem not V-shaped in cross
section; scalariform vessel perforations present; haploid chromosome number 13; pollen tectum consisting of a compound layer
of striae; leaf mesophyll not differentiated; the unique course of stem medullary bundles; D-galactose present. Its distinctive
higher haploid chromosome number, as well as its many less-specialized character states (in floral structure, leaf anatomy,
and xylem and vessel morphology), suggest thatHydrastis is a relictual primitive group which diverged early from a common ancestral stock of Ranunculaceae, Berberidaceae and probably
of Circaeasteraceae; at least some of the features shared byHydrastis and one or another of the families concerned seem to be a heritage from their common ancestor. We propose a reestablishment
of a monotypic family, Hydrastidaceae. 相似文献
5.
J. Keating L. Dratcu M. Lader R.A. Sherwood 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1993,615(2)
A reversed-phase high-performance liquid chromatographic method is described for the measurement of plasma serotonin concentrations. Sample preparation is by a simple solid-phase extraction using C18 columns. An isocratic separation is used with electrochemical detection. The application of the method to the measurement of plasma serotonin concentrations following the administration of fluvoxamine (a serotonin re-uptake inhibitor), maprotiline (a noradrenaline re-uptake inhibitor) and placebo to normal subjects for a seven-day period is reported. Fluvoxamine significantly decreases plasma serotonin over this time period in a linear fashion. No effect on plasma serotonin was seen for maprotiline or placebo. Plasma serotonin concentrations can be used to monitor compliance with fluvoxamine therapy. 相似文献
6.
T. Macedo C. A. Fontes Ribeiro D. Cotrim P. Tavares M. T. Morgadinho M. Caramona M. T. Nunes Vicente L. Rodrigues M. G. Cardoso M. L. Keating 《Molecular neurobiology》1995,11(1-3):21-29
This work evaluated in a population of heroin and heroin plus cocaine human addicts:
- Norepinephrine (NE), epinephrine (Epi), and 3-methoxy-4-hydroxyphenylglycol (MHPG) (the principal metabolite of brain NE) plasma levels;
- Monoamine oxidase (MAO) activity; and
- 3H-imipramine specific binding to the amine carrier in platelets.
7.
L Banci L B Dugad G N La Mar K A Keating C Luchinat R Pierattelli 《Biophysical journal》1992,63(2):530-543
The structure of ClO4 and NO3 adducts of cobalt(II) substituted bovine carbonic anhydrase have been investigated through 1D NOE and 2D 1H nuclear magnetic resonance (NMR) spectroscopy. For the first time two-dimensional NMR techniques are applied to paramagnetic metalloproteins other than iron-containing proteins. Several active site signals have been assigned to specific protons on the grounds of their scalar and dipolar connectivities and T1 values. The experimental dipolar shifts for the protons belonging to noncoordinated residues have allowed the identification of a plausible orientation of the magnetic susceptibility tensor around the cobalt ion as well as of the magnitude and the anisotropy of the principal susceptibility values. In turn, a few more signals have been tentatively assigned on the grounds of their predicted dipolar shifts. The two inhibitor derivatives have a very similar orientation but a different magnitude of the chi tensor, and the protein structure around the active site is highly maintained. The results encourage a more extensive use of the two-dimensional techniques for obtaining selective structural information on the active site of metalloenzymes. With this information at hand, comparisons within homologous series of adducts with various inhibitors and/or mutants of the same enzyme of known structure should be possible using limited sets of NMR data. 相似文献
8.
Sebastian Swanson Venkatesh Sivaraman Gevorg Grigoryan Amy E. Keating 《Protein science : a publication of the Protein Society》2022,31(6)
Despite advances in protein engineering, the de novo design of small proteins or peptides that bind to a desired target remains a difficult task. Most computational methods search for binder structures in a library of candidate scaffolds, which can lead to designs with poor target complementarity and low success rates. Instead of choosing from pre‐defined scaffolds, we propose that custom peptide structures can be constructed to complement a target surface. Our method mines tertiary motifs (TERMs) from known structures to identify surface‐complementing fragments or “seeds.” We combine seeds that satisfy geometric overlap criteria to generate peptide backbones and score the backbones to identify the most likely binding structures. We found that TERM‐based seeds can describe known binding structures with high resolution: the vast majority of peptide binders from 486 peptide‐protein complexes can be covered by seeds generated from single‐chain structures. Furthermore, we demonstrate that known peptide structures can be reconstructed with high accuracy from peptide‐covering seeds. As a proof of concept, we used our method to design 100 peptide binders of TRAF6, seven of which were predicted by Rosetta to form higher‐quality interfaces than a native binder. The designed peptides interact with distinct sites on TRAF6, including the native peptide‐binding site. These results demonstrate that known peptide‐binding structures can be constructed from TERMs in single‐chain structures and suggest that TERM information can be applied to efficiently design novel target‐complementing binders. 相似文献
9.
Kathleen M. Maloney Jenny Ancca‐Juarez Renzo Salazar Katty Borrini‐Mayori Malwina Niemierko Joshua O. Yukich Cesar Naquira Joseph A. Keating Michael Z. Levy 《Journal of vector ecology》2013,38(1):6-11
The vector of Chagas disease, Triatoma infestans, is largely controlled by the household application of pyrethroid insecticides. Because effective, large‐scale insecticide application is costly and necessitates numerous trained personnel, alternative control techniques are badly needed. We compared the residual effect of organophosphate‐based insecticidal paint (Inesfly 5A IGR? (I5A)) to standard deltamethrin, and a negative control, against T. infestans in a simulated natural environment. We evaluated mortality, knockdown, and ability to take a blood meal among 5th instar nymphs. I5A paint caused significantly greater mortality at time points up to nine months compared to deltamethrin (Fisher's Exact Test, p < 0.01 in all instances). A year following application, mortality among nymphs in the I5A was similar to those in the deltamethrin (χ2 = 0.76, df=1, p < 0.76). At months 0 and 1 after application, fewer nymphs exposed to deltamethrin took a blood meal compared to insects exposed to paint (Fisher's Exact Tests, p < 0.01 and p < 0.01, respectively). Insecticidal paint may provide an easily‐applied means of protection against vectors of Chagas disease. 相似文献
10.
Joseph M Mwangangi Charles M Mbogo Benedict O Orindi Ephantus J Muturi Janet T Midega Joseph Nzovu Hellen Gatakaa John Githure Christian Borgemeister Joseph Keating John C Beier 《Malaria journal》2013,12(1):1-9