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排序方式: 共有452条查询结果,搜索用时 15 毫秒
371.
Detection of desamido forms of purified bovine growth hormone 总被引:1,自引:0,他引:1
C Secchi P A Biondi A Negri R Borroni S Ronchi 《International journal of peptide and protein research》1986,28(3):298-306
Tryptic peptide mapping and amino acid sequencing were used for the identification of desamido forms of bovine growth hormone. The major desamido forms of bovine growth hormone resulted from deamidation of asparagine in position 13, 148 and glutamine 140. These forms did not seem to be produced by prolonged treatment of bovine growth hormone in tryptic hydrolysis. 相似文献
372.
Using inbreeding theory as applied to neutral alleles inherited maternally,
we generate expected probability distributions of times to identity by
descent for random pairs of mitochondrial genotypes within a population or
within an entire species characterized by high gene flow. For comparisons
with these expectations, empirical distributions of times to most recent
common ancestry were calculated (by conventional mtDNA clock calibrations)
from mtDNA haplotype distances observed within each of three vertebrate
species--American eels, hardhead catfish, and redwinged blackbirds. These
species were chosen for analysis because census population size in each is
currently large and because both genetic and life-history data are
consistent with the postulate that historical gene flow within these
species has been high. The observed molecular distances among mtDNA
lineages were two to three orders of magnitude lower than predicted from
census sizes of breeding females, suggesting that rate of mtDNA evolution
is decelerated in these species and/or that long-term effective population
size is vastly smaller than present-day population size. Several
considerations point to the latter possibility as most likely. The genetic
structure of any species is greatly influenced by historical demography;
even for species that are currently abundant, mtDNA gene lineages appear to
have been channeled through fairly small numbers of ancestors.
相似文献
373.
O Rickards G Biondi M Fuciarelli E Capucci H Walter G F De Stefano 《Human heredity》1988,38(6):332-336
Acid phosphatase (ACP1), esterase D (ESD) and phosphoglucomutase 1 (PGM1) polymorphisms have been studied in Sardinia and the following gene frequencies have been found: ACP1*A = 0.235, ACP1*B = 0.684 and ACP1*C = 0.081; ESD*2 = 0.118 and PGM1*2 = 0.233. These findings confirm the genetic uniqueness of Sardinians compared to the other Italian and European populations. 相似文献
374.
Genomic variability and alternative splicing generate multiple PML/RAR alpha transcripts that encode aberrant PML proteins and PML/RAR alpha isoforms in acute promyelocytic leukaemia. 总被引:5,自引:0,他引:5
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P P Pandolfi M Alcalay M Fagioli D Zangrilli A Mencarelli D Diverio A Biondi F Lo Coco A Rambaldi F Grignani et al. 《The EMBO journal》1992,11(4):1397-1407
375.
Elena Fabbri Maria Enrica Ferretti Marco Buzzi Roberta Cavallaro Giancarlo Vesce Prof. Carla Biondi 《Neurochemical research》1995,20(6):719-725
The enzyme adenylyl cyclase from sheep olfactory epithelium is dually regulated by GTP and is highly sensitive to the nucleotide analogues GTPS and GppNHp, as well as to fluoride ions and forskolin. Many, but not all, odorants tested are able to stimulate adenylyl cyclase in a dose-dependent manner and with different potencies. Such an effect is detectable only in the presence of GTP. The odorants belonging to the putrid class are the least effective in stimulating adenylyl cyclase activity, and only furfuryl mercaptan significantly increases cAMP biosynthesis. Mixtures of two odorants, chosen among those able to activate adenylyl cyclase, induce additive or supra-additive effects, suggesting the presence of many different receptor types. The presence of an alternative olfactory signal transduction process, i.e. the inositol phospholipid second messenger system, has been evaluated. Triethylamine, a putrid odorant completely ineffective on cAMP levels, is able to significantly increase inositol phosphate accumulation, indicating the coexistence of both cAMP- and InsP3-mediated signalling pathways in sheep olfactory epithelium. 相似文献
376.
C Bordignon F Villa P Allavena M Introna A Biondi R Avallone A Mantovani 《Journal of immunology (Baltimore, Md. : 1950)》1982,129(2):587-591
Mononuclear phagocytes were isolated by adherence from peripheral blood, peritoneal exudates, early lactation milk, ovarian carcinomatous ascites and bronchoalveolar lavages. Their capacity to modulate natural killer (NK) activity was assessed by mixing them with blood lymphocytes and by measuring lysis of 51Cr-labeled K562 cells. Unlike other mononuclear phagocyte populations, alveolar macrophages caused a marked dose-dependent inhibition of NK activity. Significant inhibition (40%) of the expression of cytotoxicity was evident at a ratio of alveolar macrophages to lymphoid cells of 0.12:1, and more than 80% suppression was usually observed at a ratio of 0.5:1. Blood monocytes, peritoneal and milk macrophages were consistently inactive up to the highest ratio tested, 2:1. Inhibition of the expression of NK activity by alveolar macrophages was observed at lymphocyte to K562 ratios ranging from 6:1 to 100:1 and over a 4 h or 20 h 51Cr release assay. Alveolar macrophages also inhibited interferon-stimulated cytotoxicity. Alveolar macrophages are unique among the mononuclear phagocyte populations studied in their capacity to inhibit the expression of NK activity effectively, and they could play a role in determining the low levels of NK activity associated with human pulmonary tissue. 相似文献
377.
Marina Gobbo Laura Biondi Fernando Filira Fernando Formaggio Marco Crisma Raniero Rocchi Claudio Toniolo Quirinus B. Broxterman Johan Kamphuis 《Letters in Peptide Science》1998,5(2-3):105-107
A series of longer analogues of the C-peptide of RNAse A has been synthesized with the aim of assessing the helix induction potential in water of -methyl, -amino acids at the N-terminus of the chain. The circular dichroism data indicate that one isovaline residue is effective in increasing the helix content of the 13-residue peptide by about 7%. 相似文献
378.
Developmental and wound-, cold-, desiccation-, ultraviolet-B-stress-induced modulations in the expression of the petunia zinc finger transcription factor gene ZPT2-2
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van Der Krol AR van Poecke RM Vorst OF Voogt C van Leeuwen W Borst-Vrensen TW Takatsuji H van Der Plas LH 《Plant physiology》1999,121(4):1153-1162
The ZPT2-2 gene belongs to the EPF gene family in petunia (Petunia hybrida), which encodes proteins with TFIIIA-type zinc-finger DNA-binding motifs. To elucidate a possible function for ZPT2-2, we analyzed its pattern of expression in relation to different developmental and physiological stress signals. The activity of the ZPT2-2 promoter was analyzed using a firefly luciferase (LUC) reporter gene, allowing for continuous measurements of transgene activity in planta. We show that ZPT2-2::LUC is active in all plant tissues, but is strongly modulated in cotyledons upon germination, in leaves in response to desiccation, cold treatment, wounding, or ultraviolet-B light, and in petal tissue in response to pollination of the stigma. Analysis of mRNA levels indicated that the modulations in ZPT2-2::LUC expression reflect modulations in endogenous ZPT2-2 gene expression. The change in ZPT2-2::LUC activity by cold treatment, wounding, desiccation, and ultraviolet-B light suggest that the phytohormones ethylene and jasmonic acid are involved in regulating the expression of ZPT2-2. Although up-regulation of expression of ZPT2-2 can be blocked by inhibitors of ethylene perception, expression in plants is not induced by exogenously applied ethylene. The application of jasmonic acid does result in an up-regulation of gene activity and, thus, ZPT2-2 may play a role in the realization of the jasmonic acid hormonal responses in petunia. 相似文献
379.
Laura Biondi Elisa Giannini Fernando Filira Marina Gobbo Mauro Marastoni Lucia Negri Barbara Scolaro Roberto Tomatisc Raniero Rocchi 《Journal of peptide science》2003,9(10):638-648
Syntheses are described of new dermorphin and [D-Ala2]deltorphin I analogues in which the phenylalanine, the tyrosine or the valine residues have been substituted by the corresponding N-alkylglycine residues. Structural investigations by CD measurements in different solvents and preliminary pharmacological experiments were carried out on the resulting peptide-peptoid hybrids. The contribution from aromatic side chain residues is prominent in the CD spectra of dermorphin analogues and the assignment of a prevailing secondary structure could be questionable. In the CD spectra of deltorphin analogues the aromatic contribution is lower and the dichroic curves indicate the predominance of random conformer populations. The disappearance of the aromatic contribution in the [Ntyr1,D-Ala2]-deltorphin spectrum could be explained in terms of high conformational freedom of the N-terminal residue. The kinetics of degradation of the synthetic peptoids digestion by rat and human plasma enzymes were compared with that of [Leu5]-enkephalin. The binding to opioid receptors was tested on crude membrane preparations from CHO cells stably transfected with the mu- and delta-opioid receptors. The biological potency of peptoids was compared with that of dermorphin in GPI preparations and with that of deltorphin I in MVD preparations. All the substitutions produced a dramatic decrease in the affinity of the peptide-peptoid hybrids for both the mu- and delta-opioid receptors. Nval5 and/or Nval6 containing hybrids behaved as mu-opioid receptor agonists and elicit a dose-dependent analgesia (tail-flick test) when injected i.c.v. in rats. 相似文献
380.
Abstract The Pepila fuscomaculata species-group from Australia, including P. fuscomaculata ( Baly 1877 ), P. hypocrita ( Blackburn 1896 ), P. submetallescens ( Baly 1877 ), P. tumbyensis ( Blackburn 1896 ), P. blackburni sp. n., P. brittoni sp. n., P. nikitini sp. n. and P. reidi sp. n., is analysed. A key to all the species is presented. Line drawings of male and female genitalia of all species are included. Brief ecological and zoogeographical data are also reported. 相似文献