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31.
Nagano CS Moreno FB Bloch C Prates MV Calvete JJ Saker-Sampaio S Farias WR Tavares TD Nascimento KS Grangeiro TB Cavada BS Sampaio AH 《Protein and peptide letters》2002,9(2):159-166
A lectin from the red marine alga Hypnea musciformis (HML) was purified by extraction with 20 mM PBS, precipitation with 70% saturated ammonium sulphate, ion-exchange DEAE-Cellulose chromatography and RP-HPLC. The 9.3 kDa polypeptide agglutinates erythrocytes from various sources and shows oligomerization tendencies under certain MALDI-TOF/MS conditions. Preliminary N-terminal sequencing and biological assays strongly suggest that the HML may belong to a new class of algae lectins. 相似文献
32.
Stanfill AA Jackson K Farias M Barlow M Deo S Johnson S Caffrey JL 《Experimental biology and medicine (Maywood, N.J.)》2003,228(8):898-906
This study examined the role of leucine-enkephalin (LE) in the sympathetic regulation of the cardiac pacemaker. LE was administered by microdialysis into the interstitium of the canine sinoatrial node during either sympathetic nerve stimulation or norepinephrine infusion. In study one, the right cardiac sympathetic nerves were isolated as they exit the stellate ganglion and were stimulated to produce graded (low, 20-30 bpm; high 40-50 bpm) increases in heart rate (HR). LE (1.5 nmoles/min) was added to the dialysis inflow and the sympathetic stimulations were repeated after 5 and 20 min of LE infusion. After 5 min, LE reduced the tachycardia during sympathetic stimulation at both low (18.2 +/- 1.3 bpm to 11.4 +/- 1.4 bpm) and high (45 +/- 1.5 bpm to 22.8 +/- 1.5 bpm) frequency stimulations. The inhibition was maintained during 20 min of continuous LE exposure with no evidence of opioid desensitization. The delta-opioid antagonist, naltrindole (1.1 nmoles/min), restored only 30% of the sympathetic tachycardia. Nodal delta-receptors are vagolytic and vagal stimulations were included in the protocol as positive controls. LE reduced vagal bradycardia by 50% and naltrindole completely restored the vagal bradycardia. In Study 2, additional opioid antagonists were used to determine if alternative opioid receptors might be implicated in the sympatholytic response. Increasing doses of the kappa-antagonist, norbinaltorphimine (norBNI), were combined with LE during sympathetic stimulation. NorBNI completely restored the sympathetic tachycardia with an ED50 of 0.01 nmoles/min. A single dose of the micro -antagonist, CTAP (1.0 nmoles/min), failed to alter the sympatholytic effect of LE. Study 3 was conducted to determine if the sympatholytic effect was prejunctional or postjunctional in character. Norepinephrine was added to the dialysis inflow at a rate (30-45 pmoles/min) sufficient to produce intermediate increases (35.2 +/- 1.8 bpm) in HR. LE was then combined with norepinephrine and responses were recorded at 5-min intervals for 20 min. The tachycardia mediated by added norepinephrine was unaltered by LE or LE plus naltrindole. At the same 5-min intervals, LE reduced vagal bradycardia by more than 50%. This vagolytic effect was again completely reversed by naltrindole. Collectively, these observations support the hypothesis that the local nodal sympatholytic effect of LE was mediated by kappa-opioid receptors that reduced the effective interstitial concentration of norepinephrine and not the result of a postjunctional interaction between LE and norepinephrine. 相似文献
33.
Citores Luca; de Benito Fernando M.; Iglesias Rosario; Ferreras J. Miguel; Jimnez Pilar; Argeso Pablo; Farias Gustavo; Mndez Enrique; Girbs Toms 《Journal of experimental botany》1996,47(10):1577-1585
Sambucus (Caprifoliaceae) species contain nigrin b and ebulinI, which are two-chain ribosomeinactivating proteins (RIPs)belonging to a new type of RIPS which are non-toxic to miceand cultured human cells. In this work the presence in fruitsof elder (S. nigra L.) of a new non-toxic type 2 RIP (nigrinf) that co-exists with a lectin known as SNA IV is described.Nigrin f strongly inhibited protein synthesis in mammalian,but not in plant, ribosomes, promoting the depurination of sensitiveribosomes and thus allowing the release of the RIP diagnosticRNA fragment. Nigrin f is composed of two dissimilar subunitslinked by disulphide bridges with apparent Mr values of 31 600and 26 300. The N-terminal amino acid sequence revealed closehomology of the catalytic A chain with type 1 RIPs, especiallythose from Cucurbitaceae, and the B chain with several lectinspreviously isolated from Sambucus species. Nigrin f was nottoxic to mice when injected intraperitoneally up to 2 mg kg1.In addition, NHC human cells were also insensitive to nigrinf up to 60 µg ml1. Anti-nigrin b rabbit polyclonalantibodies reacted with nigrin f, indicating that nigrin b andnigrin f are proteins with similar structures. Key words: Sambucus nigra, elder fruits, nigrin f, ribosomeinactivating protein, characterization 相似文献
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Tiago Collares Vinicius Farias Campos Fabiana Kömmling Seixas Paulo V. Cavalcanti Odir A. Dellagostin Heden Luiz M. Moreira João Carlos Deschamps 《Journal of biosciences》2010,35(1):39-47
The silver catfish (Rhamdia quelen) is an endemic American fish species. The sperm of each species has its own peculiarities and biological characteristics,
which influence the success of mass DNA transfer methods. Our objective in this study was to evaluate different sperm-mediated
gene transfer (SMGT) methods to obtain transgenic silver catfish. Different treatments for the incorporation of a foreign
pEGFP plasmid group were used: (1) dehydrated/rehydrated (DR), (2) dehydrated/rehydrated/electroporated (DRE), (3) electroporated
(E), (4) incubated with seminal plasma (INC); and (5) incubated in the absence of seminal plasma (INCSP). Sperm motility,
time of activity duration (TAD), fertilization rate (FR), hatching rate (HR) and sperm morphology were also evaluated. The
polymerase chain reaction (PCR) positivity rates for the presence of the transgene were: DRE 60%; DR 40%; E 25%; INC 5% and
INCSP 25%. The rates of embryo EGFP expression were: DRE 63%; DR 44%; E 34%; INC 8% and INCSP 38%. The fertilization rate
in the control and DRE treatments groups were higher than in the DR group, but the E, INC and INCSP treatment groups had the
lowest rate. The hatching rates of the DRE, DR and control groups were higher than in the INCSP, INC and E treatment groups
(P>0.05). There were no differences among the DRE and DR, E and DR, E and INCSP groups in expression and PCR positivity rates
of enhanced green fluorescent protein (EGFP) in embryos. Scanning electron microscopy also did not show any change in sperm
morphology among treatment groups. To the best of our knowledge, this is the first report on transgene transmission of exogenous
DNA into silver catfish larvae through SMGT technology. 相似文献
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39.
Toyama MH Toyama DO Torres VM Pontes GC Farias WR Melo FR Oliveira SC Fagundes FH Diz Filho EB Cavada BS 《The protein journal》2010,29(8):567-571
Low molecular weight fragments of sulfated galactans (Boc-5 and Boc-10) from the red algae Botryocladia occidentalis significantly inhibited Crotalus durissus cascavella sPLA2 enzymatic activity. Equimolar ratios of sPLA2 to Boc-5 or Boc-10 resulted in allosteric inhibition of sPLA2. Under
the conditions tested, we observed that both Boc-5 and Boc-10 strongly decreased edema, myonecrosis, and neurotoxicity induced
by native sPLA2. 相似文献
40.
Stolf-Moreira R Medri ME Neumaier N Lemos NG Pimenta JA Tobita S Brogin RL Marcelino-Guimarães FC Oliveira MC Farias JR Abdelnoor RV Nepomuceno AL 《Genetics and molecular research : GMR》2010,9(4):1946-1956
Soybean genotypes MG/BR46 (Conquista) and BR16, drought-tolerant and -sensitive, respectively, were compared in terms of morphophysiological and gene-expression responses to water stress during two stages of development. Gene-expression analysis showed differential responses in Gmdreb1a and Gmpip1b mRNA expression within 30 days of water-deficit initiation in MG/BR46 (Conquista) plants. Within 45 days of initiating stress, Gmp5cs and Gmpip1b had relatively higher expression. Initially, BR16 showed increased expression only for Gmdreb1a, and later (45 days) for Gmp5cs, Gmdefensin and Gmpip1b. Only BR16 presented down-regulated expression of genes, such as Gmp5cs and Gmpip1b, 30 days after the onset of moisture stress, and Gmgols after 45 days of stress. The faster perception of water stress in MG/BR46 (Conquista) and the better maintenance of up-regulated gene expression than in the sensitive BR16 genotype imply mechanisms by which the former is better adapted to tolerate moisture deficiency. 相似文献