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1.
Pathak M Singh B Sharma A Agrawal P Pasha SB Das HR Das RH 《Plant molecular biology》2006,62(4-5):529-545
Isolation and purification of a α-methyl-mannoside specific lectin (SL-I) of peanut was reported earlier [Singh and Das (1994) Glycoconj J 11:282–285]. Native SL-I is a glycoprotein having ∼31 kDa subunit molecular mass and forms dimer. The gene encoding this lectin is identified from a 6-day old peanut root cDNA library by anti-SL-I antibody and N-terminal amino acid sequence homology to the native lectin. Nucleotide sequence derived amino acid sequence of the re-SL-I shows amino acid sequence homology with the N-terminal and tryptic digests’ amino acid sequence of the native SL-I (nSL-I). Presence of a putative glycosylation (QNPS) site and a hydrophobic adenine-binding (VLVSYDANS) site is also identified in SL-I. Homology modeling of the lectin suggests it to be an archetype of legume lectins. It is expressed as a ~30 kDa apoprotein in E. coli and has the carbohydrate specificity and secondary structure identical to its natural counterpart. The lectin SL-I inhibits cytokinin 6-benzylaminopurine (BA)-induced “delayed leaf senescence” and “cotyledon expansion”. Equilibrium dialysis revealed a single high-affinity binding site for adenine (7.6 × 10−6 M) and BA (1.09 × 10−5 M) in the SL-I dimer and thus suggesting that the cytokinin antagonist effect of SL-I is mediated by the direct interaction of SL-I with BA.The nucleotide sequence data reported here are available in the DDBJ/EMBL/GenBank databases under the Accession No. AJ585523 相似文献
2.
Sclerotium rolfsii lectin (SRL), a secretory protein from the soil borne phytopathogenic fungus Sclerotium rolfsii, has shown in our previous studies to bind strongly to the oncofetal Thomson-Friedenreich carbohydrate (Galβ1-3GalNAc-ser/thr,
T or TF) antigen. TF antigen is widely expressed in many types of human cancers and the strong binding of SRL toward such
a cancer-associated carbohydrate structure led us to characterize the carbohydrate binding specificity of SRL. Glycan array
analysis, which included 285 glycans, shows exclusive binding of SRL to the O-linked mucin type but not N-linked glycans and
amongst the mucin type O-glycans, lectin recognizes only mucin core 1, core 2 and weakly core 8 but not to other mucin core
structures. It binds with high specificity to “α-anomers” but not the “β-anomers” of the TF structure. The axial C4-OH group
of GalNAc and C2-OH group of Gal is both essential for SRL interaction with TF disaccharide, and substitution on C3 of galactose
by sulfate or sialic acid or N-acetylglucosamine, significantly enhances the avidity of the lectin. SRL differs in its binding to TF structures compared
to other known TF-binding lectins such as the Arachis hypogea (peanut) agglutinin, Agaricus bisporus (mushroom) lectin, Jackfruit, Artocarpus integrifolia (jacalin) and Amaranthus caudatus (Amaranthin) lectin. Thus, SRL has unique carbohydrate-binding specificity toward TF-related O-linked carbohydrate structures.
Such a binding specificity will make this lectin a very useful tool in future structural as well as functional analysis of
the cellular glycans in cancer studies. 相似文献
3.
Jiřina Švachulová Eva Klozvá Věra Hadačová Věra Turková Daniela Přikrylová 《Biologia Plantarum》1984,26(5):349-357
Using biospecific chromatography on fetuin D-Glc-Separon H 1.000, lectins were isolated from the seeds of six representatives
of the speciesPhaseolus vulgaris ssp.aborigineus of different geographical origin. The lectins of all the six representatives exhibit the agglutinating activity against rabbit
erythrocytes (non-treated, tryp3in-treated and pronase-treated) as well as against human erythrocytes (irrespective of blood
group) but of different quantity. Lectins isolated from 4 seed types showed mitogenic activity against lymphocytes of murine
spleen, whereas in two seed types mitogenic activity was not proved. Isoelectric focusing in polyacrylamide gels revealed
in the different seed types 2 to 5 bands of lectins within the range of pI 4–6. Differences in the composition of lectin spectra
were proved by means of immunoelectrophoresis and double diffusion. The presence of α-D-galactosidase has not been established
in any isolated lectin. 相似文献
4.
A lectin was isolated fromCanavalia brasiliensis Mart. seeds by combining solubility fractionation with affinity chromatography on Sephadex G-50. The lectin showed a carbohydrate
specificity for D-mannose (D-glucose) binding and a requirement for Ca2+ and Mn2+. All the hemagglutinating activity was found in the cotyledons and the presence of the lectin was followed during the first
15 days of plant germination, through the activity against rabbit erythrocytes, the presence of the “lectin peak” in Sephadex
G-50 affinity chromatography, presence of the “lectin bands” in SDS-polyacrylamide gel electrophoresis and the “lectin arcs
and rockets” in immunoelectrophoresis in agarose gel. On application of all these methods the lectin showed a differentiated
metabolism, disappearing more slowly than the other high molecular weight proteins of the seed. 相似文献
5.
Xu HL Li CY He XM Niu KQ Peng H Li WW Zhou CC Bao JK 《Journal of molecular modeling》2012,18(1):27-37
The Galanthus nivalis agglutinin (GNA)-related lectin family exhibit significant anti-HIV and anti-HSV properties that are closely related to their
carbohydrate-binding activities. However, there is still no conclusive evidence that GNA-related lectins possess anti-influenza
properties. The hemagglutinin (HA) of influenza virus is a surface protein that is involved in binding host cell sialic acid
during the early stages of infection. Herein, we studied the 3D-QSARs (three-dimensional quantitative structure–activity relationships)
of lectin– and HA–sialic acid by molecular modeling. The affinities and stabilities of lectin– and HA–sialic acid complexes
were also assessed by molecular docking and molecular dynamics simulations. Finally, anti-influenza GNA-related lectins that
possess stable conformations and higher binding affinities for sialic acid than HAs of human influenza virus were screened,
and a possible mechanism was proposed. Accordingly, our results indicate that some GNA-related lectins, such as Yucca filamentosa lectin and Polygonatum cyrtonema lectin, could act as drugs that prevent influenza virus infection via competitive binding. In conclusion, the GNA-related
lectin family may be helpful in the design of novel candidate agents for preventing influenza A infection through the use
of competitive combination against sialic acid specific viral infection. 相似文献
6.
The home range of resident animals is considered as “familiar area” including a “foraging area.” It has been revealed that
the activity of an average animal unit in the “foraging area” could be approximated by normal distribution. Estimation of
activity distribution in the “familiar area” (beyond the “foraging area”) was impeded by means of marking since it might be
difficult to record distant movements, and the method does not provide an essential body of data. In the case of the common
shrew Sorex araneus, the “familiar area” was estimated using pitfall as animals evade them in the known areal. The “foraging area” radius of
the average shrew was taken to be 30 m (95% of the animal unit activity), the radius of “familiar area” was within the range
of 180–240 m. The “foraging area” was expected to provide the animal with vital resources, and the “familiar area” reflects
its need for exploratory activity. 相似文献
7.
Several aspects of the interaction of various lectins with the surface of Ehrlich ascites carcinoma cells are described. The order of agglutinating activity for various various lectins is Ricinuscommunis > wheat germ concanavalin A soybean >Limuluspolyphemus. No agglutination was noted for Ulex europaeus. Using 125I-labeled lectins it was determined that there are 1.6 and 7 times as many Ricinus communis lectin binding sites as sites for concanavalin A and soybean lectins. Sodium deoxy-cholate-solubilized plasma membrane material was subjected to lectin affinity chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The lectin receptors of the plasma membrane appeared to be heterogeneous and some qualitative differences could be discerned among the electrophoretically analyzed material, which bound to and was specifically eluted from the various lectin affinity colums. The characteristics of elution of bound material from individual lectin columns indicated secondary hydrophobic interactions between concanavalin A or wheat germ agglutinin and their respective lectin receptor molecules. 相似文献
8.
Disanthus cercidifolius Maxim. var. longipes H.T. Chang usually has two inflorescences growing in opposite directions in the axillae, but occasionally three inflorescences
grow paratactically. The typical flowering process could be divided into 4 periods: “Pre-dehiscence”, “Initial dehiscence”, “Full dehiscence” and “Withering”. Both the natural population and the planted population had a flowering peak of 15–35 days after the first flower bloomed.
There were significant differences between the time courses of flowering of the two populations. Out-crossing is the main
breeding system in this species. And autogamy decreases the risk of reproductive failure of this species. The main insect
pollinators of D. cercidifolius var. longipes are Episyrphus balteatus de Geer, Scaptodrosophila coracina Kikkawa and Peng, Polistes olivaceus de Geer, Apis cerana Fabricius, Nezara viridula L. and Coccinella septempunctata L., and so on. Among the insects, S. coracina and E. balteatus are the most important and efficient pollinators, but others are inefficient pollinators. Though wind pollination is not
efficient, it guarantees reproduction when insect pollinators are not available. “Mass flowering” is an adaptive behavior and reproductive strategy of this species, and “few fruiting” could be caused by the lack of pollinators. 相似文献
9.
10.
Jing Zhang Yan Liu Dan Yu Hongze Song Jingjin Cui Tao Liu 《Journal of applied phycology》2011,23(2):165-171
Hybridization of gametophytes, continuous self-crossing and targeted selection were utilized to breed a new Laminaria variety. After five-generation selection breeding, the new variety “Rongfu” was obtained. Its male parent “Yuanza No.10”
was the high-yield cultivation variety, and its female parent was variety “Fujian” which could tolerate relatively high seawater
temperature. “Yuanza No.10” and “Fujian” were different but complement in their morphological characteristics and biological
habits. Variety “Rongfu” was bred through their hybridization which exhibited high-yield potential and high seawater temperature
tolerance. The results of traits evaluation in consecutive years showed that “Rongfu” attained higher yields by 24–27% compared
to the control (widely used commercial variety) and also contained considerable amounts of iodine, mannitol, and algin. When
seawater temperature was 18–21°C, the blade growth of “Rongfu” was maintained and tissue loss by abrasion was significantly
lower than the control. Since the adoption of variety “Rongfu” in 2001, its cultivation areas have been extended to Shandong,
Fujian and Guangdong province and have reached 14,133 ha currently, i.e., almost one-tenth of the total cultivation areas
of Laminaria in China. The results of Random Amplified Polymorphic DNA analysis showed that the relationship between “Rongfu” and other
cultivation varieties in China was very close. 相似文献
11.
Orczyk-Pawiłowicz M Floriański J Zalewski J Katnik-Prastowska I 《Glycoconjugate journal》2005,22(7-9):433-442
The present knowledge concerning the glycan structures and role of glycoconjugates derived from amniotic fluid is fragmentary
and mainly focuses on the individual glycoproteins. The question has arisen as whether the general glycosylation pattern of
amniotic fluid glycoconjugates can change with the progression of a normal pregnancy. In the present work we have described
the dynamic, quantitative alterations in relative amounts of sialic acid and fucose linked by a variety of anomeric linkages
to subterminal oligosaccharide structures of amniotic fluid glycoconjugates in relation to pregnancy age. The analysis was
performed in the following groups of amniotic fluids derived from normal pregnancy by lectin dotting method: “2nd trimester”
(14–19 weeks), “3rd trimester” (29–37 weeks), “perinatal period” (38–40 weeks) , “delivery at term” (39–41 weeks) and “post date pregnancy” (41–43 weeks). In the “3rd trimester” the amniotic fluid glycoconjugates
contained higher relative amounts of glycans terminated by α2-6-linked sialic acid (p < 0.00002) and by α1-6 innermost fucose (p < 0.000001) than those in the 2nd trimester. In contrast, they showed the lower relative amount of fucose linked α1-3 (p < 0.02). At the perinatal period the relative amount of α2-6-linked sialic acid increased (p < 0.03), and it then decreased during delivery (p < 0.02) to the level found in the “3rd trimester” group. In the post date pregnancy all parameters studied increased. The
sialyl- and fucosyl-glycotopes of the amniotic fluid glycoconjugates may play an critical role in growth and tissue remodeling
of the foetus, as well as may might reflect maturation of a foetus. Additionally, a determination of the glycotope expressions
might be helpful in prenatal diagnosis as predictor factors for well being of mother and child. 相似文献
12.
A dense accumulation of the phototrophic consortium “Pelochromatium roseum” in a small, eutrophic, freshwater lake (Dagowsee, Brandenburg, Germany) was investigated. Within the chemocline, the number
of epibionts of the consortia represented up to 19% of the total number of bacteria. Per “P. roseum” a mean value of 20 epibionts was determined. Similar to other aquatic habitats, consortia in the Dagowsee were found only
at low light intensities (< 7 μmol quanta m–2 s–1) and low sulfide concentrations (0–100 μM). In dialysis cultures of “P. roseum”, bacterial cells remained in a stable association only when incubated at light intensities between 5 and 10 μmol quanta
m–2 s–1. Intact consortia from natural samples had a buoyant density of 1046.8 kg m–3, which was much higher than that of ambient chemocline water (995.8 kg m–3). Under environmental conditions and without motility, this density difference would result in rapid sedimentation of consortia
toward the lake bottom. Our results indicate that (1) consortia are adapted to a very narrow regime of light intensities and
sulfide concentrations, (2) motility and tactic responses must be of ecological significance for the colonization of the free
water column of lakes, and (3) phototrophic growth of consortia can be explained only by a cycling of sulfur species in the
chemocline, possibly within the consortia themselves.
Received: 27 May 1997 / Accepted: 16 September 1997 相似文献
13.
Christian Herbst Jirada Herbst Michela Carella Jörg Leppert Oliver Ohlenschläger Matthias Görlach Ramadurai Ramachandran 《Journal of biomolecular NMR》2010,47(1):7-17
An approach for generating efficient RNnnS, nk {\rm{RN}}_{n}^{\nu_{\rm{S}}, {\nu_{\rm{k}}}} symmetry-based dual channel RF pulse schemes for γ-encoded broadband 15N–13C dipolar recoupling at high magic angle spinning frequencies is presented. The method involves the numerical optimisation
of the RF phase-modulation profile of the basic “R” element so as to obtain heteronuclear double quantum dipolar recoupling sequences with satisfactory magnetisation transfer
characteristics. The basic “R” element was implemented as a sandwich of a small number of short pulses of equal duration with each pulse characterised
by a RF phase and amplitude values. The performance characteristics of the sequences were evaluated via numerical simulations
and 15N–13C chemical shift correlation experiments. Employing such 13C–15N double-quantum recoupling sequences and the multiple receiver capabilities available in the current generation of NMR spectrometers,
the possibility to simultaneously acquire 3D NCC and CNH chemical shift correlation spectra is also demonstrated. 相似文献
14.
Monoclonal antibodies (mAbs) W6/32, HC10, and 4E were used to precipitate class I antigens from 21 selected individuals with
at least oneHLA-C “blank” allele. In 19 of these individuals, characteristicHLA-C banding patterns which could be precipitated by all three HLA class I mAbs were observed on one-dimensional isoelectric focusing
gels-obviously the gene products ofHLA-C “blank”. At least four allelic HLA-C “blank” gene products with different isoelectric points could be discerned. All of them
segregated withHLA-C “blank” haplotypes in informative families; two of them were associated withHLA-B51, one withHLA-B38, and one withHLA-B18. Reactivity of the HLA-C “blank” heavy chains with mAb W6/32 indicates that they are able to associated with beta-2 microglobulin,
and hence are most probably expressed at the cell surface. 相似文献
15.
The spikemoss is marked by the unique root-producing pleurogeous rhizophore as well as the lycophytic microphyll. Imaichi
and Kato (Bot Mag Tokyo 102:369–380, 1989; Am J Bot 78:1694–1703, 1991) revealed that the exogenous developmental process in the rhizophore is clearly distinguishable from the developmental process
in the endogenous root, argued that the axial organ could be coordinate with other fundamental organs including the root and
stem, and demonstrated the “rhizophore concept.” In this paper, we report on the expression pattern of the spikemoss Selaginella class 1 KNOX gene, SuKNOX1, in the rhizophore. We show that the SuKNOX1 mRNA is specifically accumulated at the tip of the rhizophore as well as the shoot apical apex, but not in the root tip.
This result supports the “rhizophore concept” at the molecular level. 相似文献
16.
Ram Sarup Singh Ranjeeta Bhari Jatinder Singh Ashok Kumar Tiwary 《World journal of microbiology & biotechnology》2011,27(3):547-554
Mucin-specific lectin from mycelium of Aspergillus nidulans was purified using anion exchange and gel filtration chromatographic techniques with an overall recovery of 32% and 21.97-fold
purification. The purified lectin migrated as a single band in SDS–PAGE with an apparent molecular mass of 34 kDa. Carbohydrate
analysis revealed that it is a glycoprotein with total sugar content of 2.54%. Optimal agglutination was observed when serially
diluted lectin was incubated with human type O erythrocyte suspension at pH 7.0–8.0 and temperature 20–30°C. Lectin was found
to be completely stable within pH 5.0–8.0 and temperature at or below 40°C. Demetallization by extensive dialysis against
EDTA did not alter its haemagglutination activity. Lectin activity was reduced to half after 24 h incubation with urea and
thiourea, with no such effect of guanidine HCl. The lectin showed potent mitogenic response towards mouse splenocytes, attaining
a maximum at 200 μg/ml as compared to untreated control cells. Mitogenic lectins are invaluable tools to assess the functioning
of immune cells. None of the microfungal lectin has yet been investigated for mitogenic activity. This is the first report
on mitogenic activity of lectin from Aspergillus sp. 相似文献
17.
Hongyan Dai Zhihong Zhang Xiuwu Guo 《In vitro cellular & developmental biology. Plant》2007,43(1):2-8
Hawthorn (Crataegus spp.) is an important plant with a long history as an ornamental and a source of medicine. A protocol is outlined for adventitious
bud regeneration from leaf and cotyledon explants of Chinese hawthorn (C. pinnatifida Bge. var. major N.E.Br.). Adventitious buds were induced on both the leaves of sprouting winter buds and the leaves of in vitro plants, but the percentage of bud regeneration from leaves of in vitro plants was very low—less than 6%. On N6 medium supplemented with 31.08 μM BA and 9.67 μM NAA, the percentages of bud regeneration
from leaves of sprouting winter buds of cultivars “Liaohong” and “Qiujinxing” were 31.4% and 17.6%, respectively. The regeneration
abilities of three kinds of cotyledon explants, immature cotyledon, mature cotyledon, and cotyledon leaf, were compared. The
percentage of bud regeneration from cotyledon leaves was higher. On MS media supplemented with 4.44 μM BA and 4.54–9.08 μM
TDZ, the percentages of bud regeneration from cotyledon leaves of cultivars “Qiujinxing” and “Xiajinxing” were 27.7 ± 7.8%
and 20.1 ± 4.7%, respectively, and the numbers of buds per explant were 5.9 ± 1.6 and 3.2 ± 0.7, respectively. On B5 medium
supplemented with 2.22 μM BA, 2.32 μM Kn, and 0.57 μM IAA, adventitious buds grew quickly and 80–100% of buds developed into
shoots. The shoots rooted successfully with the two-step rooting method. Ninety days after transplantation, more than 80%
plants were survived. This system of adventitious bud regeneration from leaf and cotyledon explants could be useful for the
genetic transformation and polyploidization of Chinese hawthorn. 相似文献
18.
Saba Ambreen Memon Xilin Hou Bo Zhu Joseph N. Wolukau 《Acta Physiologiae Plantarum》2009,31(6):1191-1196
The objective of the present work was selection of cultivar and suitable medium for regenerating shoots from leaf segments
of non-heading Chinese cabbage. We evaluated six types of supplemented media with 2.0, 5.0 and 10.0 mg l−1 6-BA; 1.0 and 2.0 mg l−1 TDZ; 0.1, 0.3, 0.5, 0.8 and 1.0 mg l−1NAA; 3.0, 5.0 and 7.5 mg l−1AgNO3; 0.01 mg l−1 2–4, D and 4.0 mg l−1 KT for shoot regeneration and six cultivars “Sanchidaye”, “Liuchuandasuomian”, “Qingyou 4”, “Liangbaiye”, “AiKang 5” and
“Hanxiao F3”, furthermore for root formation three types of supplemented media with 0.2, 0.3, 0.5 mg l−1 NAA, and for survival rate two types of base media: turf + vermiculite + manure (1:2:0.2) and soil + vermiculite (1:2). Culturing
leaf segments on MS medium supplemented with 2 mg l−1 TDZ; 0.5 mg l−1 NAA and 7.5 mg l−1 AgNO3 gave the highest number of shoots per leaf segment (66) while roots were best formed on the medium supplemented with 0.2 mg l−1 NAA. Survival rate was highest (61.6%) in the turf: vermiculite: manure (1:2:0.2) medium. The highest percentage of responding
leaf segments, number of shoots per leaf segment, rooting percentage and survival rate were observed in “Liuchuandasuomian”.
The plantlets were transferred to the soil and grown into mature plants in pots. These results could be used for preliminary
selections of cultivars to transfer disease resistance (Bt) gene through agrobacterium in non-heading Chinese cabbage. 相似文献
19.
N. Rashevsky 《Bulletin of mathematical biology》1967,29(3):643-648
In continuation of previous studies (Bull. Math. Biophysics,28, 283–308; 655–661, 1966;29, 139–152, 1967) it is shown that the difference between the “metric” aspects of physics and the “relational” aspects of biological
and social sciences disappear by accepting the broader definition of “relation”, such as that given in mathematics and logic.
A conceptual superstructure then becomes possible from which all three branches of knowledge may be derived, though none of
them can be derived from the others. 相似文献
20.
Orosomucoid (ORM) typing by print lectinofixation: a new technique for isoelectric focusing. Two common alleles in Japan 总被引:2,自引:0,他引:2
Summary The genetic types of orosomucoid (ORM) were analyzed by isoelectric focusing (IEF) on polyacrylamide gels and subsequent print
lectinofixation with a lectin from the beetle, allo A. In this paper, the newly devised print lectinofixation for ORM typing
is described. This technique is faster, easier to perform, and has been found to be a useful tool in population genetics and
forensic medicine. The results of typing for two alleles, ORM
*1 and ORM
*2 are described for a population of Northern Japan (n=500).
We use the designation “lectinofixation” to denote the method using lectin in place of monospecific antibody in the immunofixation 相似文献