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11.
Maslov L. N. Naryzhnaya N. V. Sementsov A. S. Derkachev I. A. Gusakova S. V. Sarybaev Akpay 《Journal of Evolutionary Biochemistry and Physiology》2022,58(4):1174-1179
Journal of Evolutionary Biochemistry and Physiology - The study was carried out in male Wistar rats. Animals were randomly divided into normoxic control groups and groups exposed to normobaric... 相似文献
12.
Thomas GH; Newbern EC; Korte CC; Bales MA; Muse SV; Clark AG; Kiehart DP 《Molecular biology and evolution》1997,14(12):1285-1295
Many structural, signaling, and adhesion molecules contain tandemly
repeated amino acid motifs. The alpha-actinin/spectrin/dystrophin
superfamily of F-actin-crosslinking proteins contains an array of triple
alpha-helical motifs (spectrin repeats). We present here the complete
sequence of the novel beta-spectrin isoform beta(Heavy)- spectrin (beta H).
The sequence of beta H supports the origin of alpha- and beta-spectrins
from a common ancestor, and we present a novel model for the origin of the
spectrins from a homodimeric actin-crosslinking precursor. The pattern of
similarity between the spectrin repeat units indicates that they have
evolved by a series of nested, nonuniform duplications. Furthermore, the
spectrins and dystrophins clearly have common ancestry, yet the repeat unit
is of a different length in each family. Together, these observations
suggest a dynamic period of increase in repeat number accompanied by
homogenization within each array by concerted evolution. However, today,
there is greater similarity of homologous repeats between species than
there is across repeats within species, suggesting that concerted evolution
ceased some time before the arthropod/vertebrate split. We propose a
two-phase model for the evolution of the spectrin repeat arrays in which an
initial phase of concerted evolution is subsequently retarded as each new
protein becomes constrained to a specific length and the repeats diverge at
the DNA level. This evolutionary model has general applicability to the
origins of the many other proteins that have tandemly repeated motifs.
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13.
Comparisons of the molecular evolutionary process at rbcL and ndhF in the grass family (Poaceae) 总被引:1,自引:1,他引:1
We examine rate heterogeneity among evolutionary lineages of the grass
family at two plasmid loci, ndhF and rbcL, and we introduce a method to
determine whether patterns of rate heterogeneity are correlated between
loci. We show both that rates of synonymous evolution are heterogeneous
among grass lineages and that are heterogeneity is correlated between loci
at synonymous sites. At nonsynonymous sites, the pattern of rate
heterogeneity is not correlated between loci, primarily due to an aberrant
pattern of rate heterogeneity at nonsynonymous sites of rbcL. We compare
patterns of synonymous rate heterogeneity to predictors based on the
generation time effect and the speciation rate hypotheses. Although there
is some evidence for generation time effects, neither generation time
effects nor speciation rates appear to be sufficient to explain patterns of
rate heterogeneity in the grass plastid sequences.
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14.
Petrova I. V. Birulina Yu. G. Belyaeva S. N. Trubacheva O. A. Sidekhmenova A. V. Smagliy L. V. Kovalev I. V. Gusakova S. V. 《Biophysics》2020,65(4):614-618
Biophysics - We investigated the effects of the H2S and CO gasomediators on Ca2+-dependent potassium channels and an anion exchanger, which participate in the induction of the hyperpolarization... 相似文献
15.
G V Gusakova G S Denisov A L Smolianski? A D Kuzovkov Iu V Zhdanovich 《Antibiotiki i khimioterapii͡a》1988,33(2):102-105
IR spectra of rosamycin and its solutions in inert (CCl4 and C2Cl4), proton acceptor (tetrahydrofuran, hexametapol and diethylamine) and proton donor (CHCl3 and CH3OD) solvents were studied at various concentrations (0.1 to 0.001 mol/l) and temperatures (20 to 100 degrees C) in the region of the vC = O and vOH absorption bands (1600-1800 and 3200 3650 sm 1). It was found that the absorption bands at 3480 and 3560 sm-1 observed in the spectra of rosamycin diluted solutions in the inert solvents referred to variations of vOH...N of the aminosugar fragment and to vOH...O = C of the ester group of the macrocycle. Bands at 1697 and 1717 sm-1 referred to vC = O of the ketone and aldehyde carbonyl groups and band at 1728 sm-1 referred to vC = O of the ester group whose carbonyl was involved in the C = H...HO intramolecular hydrogen bond. Intensity of vC = O band (1745 sm-1) of the free ester group was nought. However, it increased with using the proton acceptor solvents. OH...N and OH...O = C intramolecular hydrogen bonds stabilized rosamycin molecule conformation. Mechanism of rosamycin interaction with the proton donor and acceptor molecules was elucidated. It was shown that tertiary nitrogen was the center of rosamycin molecule protonation. 相似文献
16.
Hannah Gardener Della David Morte Mitchell SV Elkind Ralph L Sacco Tatjana Rundek 《BMC cardiovascular disorders》2009,9(1):1-8
Background
Heterogeneity in B-type natriuretic peptide (BNP) levels, especially among individuals with acute heart failure with normal left ventricular ejection fraction (HFNEF), can cause confusion in interpreting results. We investigated the characteristics of cases of acute HFNEF with only modestly elevated BNP.Methods
One hundred forty-two patients with acute or acute exacerbation of chronic HFNEF were divided into two groups by BNP level: BNP < 100 pg/ml (NB group, n = 45) and BNP ≥ 100 pg/ml (B group, n = 97). We compared clinical findings, echocardiography results, and neurohormonal factors between these two groups.Results
In the NB group, a history of open-heart surgery (OHS) was more frequent (71% vs. 22%, p < 0.0001) and hypertension was less frequent (p = 0.0005). Left atrial diameter (LAd) was higher (p = 0.0026), while interventricular septal thickness, posterior wall thickness, relative wall thickness, left ventricular mass index were lower (p = 0.0005, p = 0.0225, p = 0.0114, p = 0.0051, respectively) in the NB group. In patients with HFNEF, a history of OHS remained an independent predictor of BNP level (< 100 pg/ml) after adjustment for hypertension, age, LAd, and interventricular septal thickness (odds ratio 3.6, p = 0.0252).Conclusion
We found associations between acute HFNEF with less elevated BNP and a history of OHS. In a patient suspected of HFNEF, a history of OHS is considered diagnostic evidence of presence of diastolic heart failure when plasma levels of BNP are less elevated. 相似文献17.
Diaz-Perez, S. V., Crouch, V. W., and Orbach, M. J. 1996. Construction and characterization of a Magnaporthe grisea bacterial artificial chromosome library. Fungal Genet. Biol. 20, 280-288. A bacterial artificial chromosome (BAC) library of Magnaporthe grisea containing 4128 clones with an average insert size of 66-kb has been constructed. This library represents seven genome equivalents of M. grisea and has been demonstrated to be representative of the genome by screening for the presence of several single-copy genes and DNA markers. The utility of the library for use in map-based cloning projects was shown by the spanning of a nine-cosmid, 207-kb DNA contig with only 3 BAC clones. In addition, using a lys1-3 auxotroph, we have shown that BAC clones at least 113 kb can be transformed into M. grisea to screen for complementation of mutations. Thus, BACs isolated in chromosome walks can be rapidly screened for the presence of the sought after gene. The ease of construction of BAC libraries and of isolation and manipulation of BAC clones makes the BAC system an ideal one for physical analyses of fungal genomes. 相似文献
18.
Kshitiz?GuptaEmail author Dina?Thomas SV?Vidya KV?VenkateshEmail author S?Ramakumar 《BMC bioinformatics》2005,6(1):105
Background
The chemical property and biological function of a protein is a direct consequence of its primary structure. Several algorithms have been developed which determine alignment and similarity of primary protein sequences. However, character based similarity cannot provide insight into the structural aspects of a protein. We present a method based on spectral similarity to compare subsequences of amino acids that behave similarly but are not aligned well by considering amino acids as mere characters. This approach finds a similarity score between sequences based on any given attribute, like hydrophobicity of amino acids, on the basis of spectral information after partial conversion to the frequency domain. 相似文献19.
Kovalev IV Baskakov MB Medvedev MA Minochenko IL Kilin AA Anfinogenova IaD Borodin IuV Gusakova SV Popov AG Kapilevich LV Orlov SN 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2007,93(3):306-317
Influence of Na+,K+,2Cl(-)-cotransport and chloride permeability of the cell membrane on electrically-induced action potential and contraction of smooth muscle cells from guinea pig ureter was examined with the methods of the double sucrose gap junction. Mesatone (10 microM) and histamine (10 microM) induced prolongation of the action potential and elevation of smooth muscle cell contraction, whereas hyperosmic medium (+150 mM sucrose), and recovery of solution osmolality in hyposmic condition (70 mM NaCl) after a single contraction. Inhibitor Na+,K+,2Cl(-)-cotransport bumetanide (10 microM) and chloride permeability blockers niflumic acid (10-100 microM) and SITS (10-500 microM) attenuated stimulating effects of mesatone, histamine and hyperosmic medium. In opposite to adenylate cyclase activation with forskolin (1 microM), guanylate cyclase activation with sodium nitroprusside (SN, 100 microM) decreased both inhibitory action of bumetanide, niflumic acid and activating effects of mesatone, histamine on action potential and elevation contraction of smooth muscle cells. Influence of forskolin rather and not SN on AP and SMC C was inhibited with tetraethylammonium (5 mM). These results suggest that influence of Na+,K+,2Cl(-)-cotransport on electrical and contractil properties of ureter smooth muscle cells is mediated by stimulation of Ca(2+)-activated chloride permeability of the cell membrane and modulated by intracellular cGMP, but not triggered by Ca2+ release from sarcoplasmic reticulum. 相似文献
20.
Estimating synonymous and nonsynonymous substitution rates 总被引:8,自引:4,他引:4
Partitioning the total substitution rate into synnonymous and nonsynonymous
components is a key aspect of many analyses in molecular evolution.
Numerous methods exist for estimating these rates. However, until recently
none of the estimation procedures were based on a sound statistical
footing. In this paper, the evolutionary model of Muse and Gaut (1994) is
used as the basis for two sets of parameters quantifying silent and
replacement substitution rates. The parameters are shown to be equal when
the four nucleotides are equally frequent and unequal otherwise.
Maximum-likelihood estimation of these parameters is described, and the
performance of these estimates is compared to that of existing estimation
procedures. It is shown that the estimates of Nei and Gojobori (1986) are
not unbiased for either set of parameters, although they provide very good
estimates for one set as long as sequence divergence is not too high.
However, some disturbing properties are found for the Nei and Gojobori
estimates. In particular, it is shown that the expected value of the Nei
and Gojobori estimate of silent substitution rate is a function of both the
silent and replacement substitution rates. The maximum-likelihood estimates
have no such problems.
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