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1.
C. L. Díaz M. Hosselet G. J. J. Logman E. van Driessche B. J. J. Lugtenberg J. W. Kijne 《Planta》1990,181(4):451-461
We report on the distribution and initial characterization of glucose/mannose-specific isolectins of 4- and 7-d-old pea (Pisum sativum L.) seedlings grown with or without nitrate supply. Particular attention was payed to root lectin, which probably functions as a determinant of host-plant specificity during the infection of pea roots by Rhizobium leguminosarum bv. viciae. A pair of seedling cotyledons yielded 545±49 g of affinity-purified lectin, approx. 25% more lectin than did dry seeds. Shoots and roots of 4-d-old seedlings contained 100-fold less lectin than cotyledons, whereas only traces of lectin could be found in shoots and roots from 7-d-old seedlings. Polypeptides with a subunit structure similar to the precursor of the pea seed lectin could be demonstrated in cotyledons, shoots and roots. Chromatofocusing and isoelectric focusing showed that seed and non-seed isolectin differ in composition. An isolectin with an isoelectric point at pH 7.2 appeared to be a typical pea seed isolectin, whereas an isolectin focusing at pH 6.1 was the major non-seed lectin. The latter isolectin was also found in root cell-wall extracts, detached root hairs and root-surface washings. All non-seed isolectins were cross-reactive with rabbit antiserum raised against the seed isolectin with an isolectric point at pH 6.1. A protein similar to this acidic glucose/mannose-specific seed isolectin possibly represents the major lectin to be encountered by Rhizobium leguminosarum bv. viciae in the pea rhizosphere and at the root surface. Growth of pea seedlings in a nitrate-rich medium neither affected the distribution of isolectins nor their hemagglutination activity; however, the yield of affinity-purified root lectin was significantly reduced whereas shoot lectin yield slightly increased. Agglutination-inhibition tests demonstrated an overall similar sugar-binding specificity for pea seed and non-seed lectin. However root lectin from seedlings grown with or without nitrate supplement, and shoot lectin from nitrate-supplied seedlings showed a slightly different spectrum of sugar binding. The absorption spectra obtained by circular dichroism of seed and root lectin in the presence of a hapten also differed. These data indicate that nutritional conditions may affect the sugar-binding activity of non-seed isolectin, and that despite their similarities, seed and non-seed isolectins have different properties that may reflect tissue-specialization.Abbreviations IEF
isoelectric focusing
- MW
molecular weight
- pI
isoelectric point
- Psl1, Psl2 and Psl3
pea isolectins
- SDSPAGE
sodium dodecyl sulfate polyacrylamide gel electrophoresis
The authors wish to thank Professors L. Kanarek and M. van Poucke for helpful discussions. 相似文献
2.
The expression of a lectin gene in pea (Pisum sativum L.) roots has been investigated using the copy DNA of a pea seed lectin as a probe. An mRNA which has the same size as the seed mRNA but which is about 4000 times less abundant has been detected in 21-d-old roots. The probe detected lectin expression as early as 4 d after sowing, with the highest level being reached at 10 d, i.e. just before nodulation. In later stages (16-d- and 21-d-old roots), expression was substantially decreased. The correlation between infection by Rhizobium leguminosarum and lectin expression in pea roots has been investigated by comparing root lectin mRNA levels in inoculated plants and in plants grown under conditions preventing nodulation. Neither growth in a nitrate concentration which inhibited nodulation nor growth in the absence of Rhizobium appreciably affected lectin expression in roots.Abbreviation cDNA
copy DNA
- poly(A)+RNA
polyadenylated RNA 相似文献
3.
C. L. Díaz P. C. van Spronsen R. Bakhuizen G. J. J. Logman E. J. J. Lugtenberg J. W. Kijne 《Planta》1986,168(3):350-359
The lectin on the surface of 4- and 5-dold pea roots was located by the use of indirect immunofluorescence. Specific antibodies raised in rabbits against pea seed isolectin 2, which crossreact with root lectins, were used as primary immunoglobulins and were visualized with fluorescein- or tetramethylrhodamine-isothiocyanate-labeled goat antirabbit immunoglobulin G. Lectin was observed on the tips of newly formed, growing root hairs and on epidermal cells located just below the young hairs. On both types of cells, lectin was concentrated in dense small patches rather than uniformly distributed. Lectin-positive young hairs were grouped opposite the (proto)xylematic poles. Older but still-elongating root hairs presented only traces of lectin or none at all. A similar pattern of distribution was found in different pea cultivars, as well as in a supernodulating and a non-nodulating pea mutant. Growth in a nitrate concentration which inhibits nodulation did not affect lectin distribution on the surface of pea roots of this age. We tested whether or not the root zones where lectin was observed were susceptible to infection by Rhizobium leguminosarum. When low inoculum doses (consisting of less than 106 bacteria·ml-1) were placed next to lectin-positive epidermal cells and on newly formed root hairs, nodules on the primary roots were formed in 73% and 90% of the plants, respectively. Only a few plants showed primary root nodulation when the inoculum was placed on the root zone where lectin was scarce or absent. These results show that lectin is present at those sites on the pea root that are susceptible to infection by the bacterial symbiont.Abbreviations FITC
fluorescein isothiocyanate
- TRIC
tetramethylrhodamine isothiocyanate 相似文献
4.
The glucose-specific peanut root lectin, PRA II, is localized on the surface of 7-day-old peanut seedling root and in root cortical parenchymatous cells. The lectin is eluted from intact roots upon washing with buffer containing glucose. Rabbit erythrocytes bind to the root surface and the cortical cells; the binding is inhibited by antibodies raised against PRA II, peanut-specificRhizobium cells and by glucose. Lipopolysaccharides isolated from host-specificRhizobium strain inhibit the haemagglutinating activity of PRA II and are precipitated by the lectin. Our results suggest that PRA II might be involved in recognition ofRhizobium by peanut roots. 相似文献
5.
Z. R. Vershinina An. Kh. Baimiev D. K. Blagova A. V. Knyazev Al. Kh. Baimiev A. V. Chemeris 《Applied Biochemistry and Microbiology》2011,47(3):304-310
Hairy roots in tobacco and oil seed rape transgenic on lectin gene were obtained with the use of a wild strain of Agrobacterium rhizogenes 15834 transformed with pCAMBIA1305.1 plasmid containing the full-size lectin gene (psl) from the Pisum sativum. Influence of expression of lectin gene on colonization of transgenic roots with symbiont of pea (Rhizobium leguminosarum) was investigated. The number of adhered bacteria onto the roots transformed with lectin gene was 14-fold and 37-fold higher
in comparison with the control; this confirms the interaction of R. leguminosarum with pea lectin at the surface of the transformed roots of tobacco and oil seed rape. The developed experimental approach,
based on the simulation of recognition processes and early symbiotic interactions with lectins of pea plants, may, in perspective,
be used for obtaining stable associations of economically valuable, nonsymbiotrophic plant species with rhizobia. 相似文献
6.
The occurrence of high haemagglutinating (lectin) activity in phloem exudate from three cucurbit species is reported. The protein responsible for this lectin activity in Cucurbita maxima Duch. has been isolated by cation exchange chromatography on Sepharose and identified by gel electrophoresis. The lectin showed agglutinating activity at concentrations as low as 0.1 g/ml. No sugar, including those transported in the phloem of these species, interacted with agglutination. The lectin could not be extracted from cucurbit seed, but appeared in 5-day old seedlings. The possible role of a lectin in the sieve element is discussed. 相似文献
7.
Benildo S. Cavada Socorro V. F. Madeira Juan J. Calvete Luiz A. G. Souza Liezelotte R. Bomfim Adilson R. Dantas 《Preparative biochemistry & biotechnology》2013,43(4):271-280
ABSTRACT A glucose/mannose-binding lectin was isolated from seeds of Parkia discolor (Mimosoideae) using affinity chromatography on Sephadex G-100 gel. The protein presented a unique component in SDS-PAGE corresponding to a molecular mass of 58,000 Da, which is very similar to that of a closely related lectin from Parkia platycephala. Among the simple sugars tested, mannose was the best inhibitor, but biantennary glycans, containing the trimannoside core, present in N-glycoproteins, also seem to be powerful inhibitors of the haemagglutinating activity induced by the purified lectin. The protein was characterised by high content of glycine and proline and absence of cysteine. Rabbit antibodies, anti-P. platycephala seed lectin, recognised the P.discolor lectin. However, no cross-reaction was observed when a set of other legume lectins from sub-family Papilionoideae and others from families Moraceae and Euphorbiaceae were assayed with the Parkia lectins. This suggests that Parkia lectins comprise a new group of legume lectins exhibiting distinct characteristics. 相似文献
8.
Hapten-inhibition studies showed that 3-O-methyl-D-glucose andmethyl--D-mannopyranoside, which are strong sugar haptens ofhemagglutination by pea seed lectins, inhibited (a) bindingof pea seed lectins with Rhizobium leguminosarum J357 cells,(b) the precipitin reaction of pea seed lectins with a capsularpolysaccharide from J357 cells and (c) adsorption of J357 cellsto a pea root. When the capsular polysaccharide was absorb edby the lectins or oxidized by periodate to remove the precipitinreactivity with the lectin, the inhibitory activity of the capsularpolysaccharide towards the adsorption disappeared. I.ectins,which were isolated from the bathing solution of pea roots inacid buffer (pH 2.1), were similar to the seed lectins in sugar-bindingspecificity. The possible existence of lectins on pea root hairsurface was shown by the indirect imraunofluorescent antibodytechnique in combination with the biotin-avidin system. Theseresults suggest that host recognition in Rhizobium-pea. symbiosisis based on the interaction between rhizobial cells and hostlectins.
1Present address: Nodai Research Institute, Tokyo Universityof Agriculture, Setagaya-ku, Tokyo 156, Japan. (Received February 18, 1981; Accepted May 2, 1981) 相似文献
9.
Flip J. Hoedemaeker Michael Richardson Clara L. Díaz B. Sylvia de Pater Jan W. Kijne 《Plant molecular biology》1994,24(1):75-81
The complete amino acid sequences of the -subunits of pea (Pisum sativum L.) seed and root lectin, the C-terminal amino acids of the -subunits of pea seed lectin, and most of the sequence of the -subunit of pea root lectin were determined. In contrast to earlier reports it was shown that the -subunits of both seed isolectins end at Asn-181. The 1 subunits end at Gln-241 (major fraction) or Lys-240 (minor fraction), whereas the 2 subunits end at Ser-239, Ser-238, Ser-237 or Thr-236. psl cDNA clones from seed are identical to psl cDNA clones from root, and root PSL is identical to seed PSL2, ending at Ser-239, Ser-238 or Ser-237. It seems that the presence of Lys-240 is the sole determinant of the charge difference between pea isolectins. PSL1 can be converted into PSL2 by carboxypeptidase P from Penicillium janthinellum. These results confirm that PSL from roots is encoded by the same gene as PSL from seeds. Thus, it seems that, next to an Asn-X specific protease responsible for the processing at positions 181/182 and 187/188, a carboxypeptidase is responsible for the conversion of PSL1 into PSL2, which is probably the final processing product. 相似文献
10.
We report the predicted sequence of four vegetative homologues (Blec1,2,3 and 4) of the pea seed lectin. This study indicates that, in contrast to the single-copy pea seed lectin (Kaminski et al., Plant Mol Biol 9: 497–507, 1987), the pea vegetative lectin is transcribed by at least four members of a highly conserved multigene family whose members are only distantly related to the pea seed lectin at the primary amino-acid sequence level. For example, Blec1 shares only 38% amino-acid identity with the pea seed lectin. However, molecular homology modelling predicts that Blec1 probably forms a similar tertiary structure to the pea seed lectin. 相似文献
11.
Pea lectin is correctly processed,stable and active in leaves of transgenic potato plants 总被引:5,自引:0,他引:5
Glyn A. Edwards Andrew Hepher Stephen P. Clerk Donald Boulter 《Plant molecular biology》1991,17(1):89-100
A gene encoding the preproprotein of the pea (Pisum sativum) lectin was expressed in transgenic potato plants using a cauliflower mosaic virus (CaMV) 35S promoter or a tobacco ribulose bisphosphate carboxylase small subunit (ssRubisco) promoter. Presence of the pea lectin to levels greater than 1% of total soluble leaf protein was detected by radioimmunoassay (RIA). The pattern of expression derived from the two promoters was established using both RIA and a squash-blot immunolocalisation technique. Western blotting demonstrated that the preproprotein was correctly processed, generating and subunits that assembled to give an isolectin form observed in pea seeds and roots. It was also found that the haemagglutination activity and specificity of pea lectin synthesised in transgenic potato leaves was comparable to purified lectin from pea cotyledons. 相似文献
12.
Root lectins are believed to participate in the recognition between Rhizobium and its leguminous host plant. Among other factors, testing this hypothesis is difficult because of the very low amounts in which root lectins are produced. A double-antibody-sandwich enzyme-linked immunoassay, was used to determine nanogram quantities of pea lectin in root slime and salt extracts of root cell-wall material when pea seedlings were 4 and 7 d old. In addition, a critical NO
3
-
concentration (20 mM) which inhibited nodulation was found, and the lectin present in root slime and salt extracts of root cell walls of 4- and 7-d-old peas supplied with 20 mM NO
3
-
was comparatively determined. With the enzyme-linked immunoassay, lectin quantities ranging between 20 and 100 nanograms could be determined. The assay is not affected by monomeric mannose and glucose (pealectin haptens). The slime of the 4-d-old roots contained more lectin than the slime of the 7-d-old roots. Salt-extractable, cell-wall-associated lectin accumulated in the older roots. Nitrate affected slime and cell-wall production, and the extractability of cell-wall material in both age groups. The presence of NO
3
-
increased lectin in the slime, most notably in the younger roots; the relative amount of lectin in the slime was almost doubled. The cell-wall-associated, salt-extractable lectin decreased two- to threefold compared with the control group.Abbreviations ELISA
enzyme-linked immunoassay
- PTN
0.01 M phosphate buffer (pH 7.4), containing 0.15 M NaCl, 0.05% Tween-20 and 0.02% NaN3
Dedicated to Professor A. Quispel on the occasion of his retirement 相似文献
13.
In-vivo synthesis of the white-clover lectin, trifoliin A, was examined by the incorporation of labeled amino acids into protein during heterotrophic growth of intact Trifolium repens L. seedlings. Lectin synthesis was quantified by measuring the level of labeled protein immunoprecipitated from root exudate, from the hapten (2-deoxyglucose) eluate of the roots, and from root and shoot homogenates. The presence of labeled trifoliin A was confirmed by non-denaturing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by fluorography and comparison with trifoliin A standards. In-vivo-labeled trifoliin A was detected in seedling root homogenate 2 h after the addition of labeled amino acids and on the root surface by 8 h. Incorporation of labeled amino acids into protein and trifoliin A was greatest with 2-d-old seedlings and was greater when the plants were grown continuously in the dark than when they were exposed to 14 h light daily. Significantly more labeled lectin accumulated on the root surface of seedlings grown with 1.5 mM KNO3 than of seedlings grown either without N or with 15.0 mM KNO3. The labeled lectin from the root surface in all nitrate treatments and from the rootexudate samples of seedlings grown N-free and with 1.5 mM KNO3 was fully able to bind to Rhizobium trifolii. In contrast, only 2% of the immunoprecipitable protein found in the root exudate of seedlings grown with 15.0 mM KNO3 was able to bind to the bacteria. Thus, excess nitrate does not repress the synthesis of trifoliin A in the root, but does affect the distribution and activity of this newly synthesized lectin in a way which reduces its ability to interact with R. trifolii. By using Western blot analysis, much more total trifoliin A is detected in the homogenates of shoots than roots. However, greater than 80% of the total labeled protein and 85–90% of the total labeled lectin were found in the root homogenates of 2-d-old dark-grown seedlings incubated for 5 h with labeled amino acids. In addition, Western blot analysis indicated that the shoot homogenate contained smaller-molecular-weight peptides which reacted with the specific anti-trifoliin A antibody. These studies indicate that stored trifoliin A in the seed is degraded in the shoots during seedling development, while newly synthesized trifoliin A in the roots is excreted to the root surface and external environment.Abbreviations IgG
immunoglobulin G
- LPS
lipopolysaccharide
- PBS
10 mM potassium-phosphate buffer, pH 7.0, containing 0.8% NaCl
- PBS-T
20 mM phosphate-buffered saline, pH 7.4, containing 0.05% Tween 20
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis 相似文献
14.
Summary The axial root growth force exerted by seedlings of pea (Pisum sativum cv. Greenfeast), cotton (Gossypium hirsutum cv. Sicot 3) and sunflower (Helianthus annuus cv. Hysun) was measured. Effects of different seedling age and different batches of seeds on axial root growth pressure were
investigated.
Mean values of the maximum axial root growth pressure (Pa) estimated from the maximum axial root growth force (Fmax) and root diameter were 497, 289, and 238 kPa respectively for pea, cotton and sunflower seedlings of same size. Pa and Fmax were significantly influenced by seedling age and for pea seedlings of same age they varied with the seed batch.
A new technique was developed for estimating radial root growth pressure and was tested on pea seedlings. Each pea root was
confined both in the axial and radial directions in a cylindrical chalk sample at a constant water potential. The roots exerted
radial stress which caused tensile failure in a proportion of the chalks. The measurement of tensile strength of duplicate
chalks enabled estimation of the maximum radial pressures exerted by the roots. The maximum axial and radial root growth pressures
were of comparable magnitude. 相似文献
15.
Total protein patterns were studied in the course of development of pea somatic embryos using simple protocol of direct regeneration
from shoot apical meristems on auxin supplemented medium. Protein content and total protein spectra (SDS-PAGE) of somatic
embryos in particular developmental stages were analysed in Pisum sativum, P. arvense, P. elatius and P. jomardi. Expression of seed storage proteins in somatic embryos was compared with their accumulation in zygotic embryos of selected
developmental stages. Pea vegetative tissues, namely leaf and root, were used as a negative control not expressing typical
seed storage proteins. The biosynthesis and accumulation of seed storage proteins was observed during somatic embryo development
(since globular stage), despite of the fact that no special maturation treatment was applied. Major storage proteins typical
for pea seed (globulins legumin, vicilin, convicilin and their subunits) were detected in somatic embryos. In general, the
biosynthesis of storage proteins in somatic embryos was lower as compared to mature dry seed. However, in some cases the cotyledonary
somatic embryos exhibited comparatively high expression of vicilin, convicilin and pea seed lectin, which was even higher
than those in immature but morphologically fully developed zygotic embryos. Desiccation treatments did not affect the protein
content of somatic embryos. The transfer of desiccated somatic embryos on hormone-free germination medium led to progressive
storage protein degradation. The expression of true seed storage proteins may serve as an explicit marker of somatic embryogenesis
pathway of regeneration as well as a measure of maturation degree of somatic embryos in pea. 相似文献
16.
Two lectins were purified by affinity chromatography from mature peanut (Arachis hypogaea L.) nodules, and compared with the previously characterised seed lectin of this plant. One of the nodule lectins was similar to the seed lectin in its molecular weight and amino-acid composition and ability to bind derivatives of galactose. However, unlike the seed lectin, this nodule lectin appeared to be a glycoprotein and the two lectins were only partially identical in their reaction with antibodies prepared against the seed lectin. The other nodule lectin also appeared to be a glycoprotein but bound mannose/glucose-like sugar derivatives, and differed from the seed lectin in molecular weight, antigenic properties and amino-acid composition.Abbreviations Gal
galactose
- Gle
glucose
- GNL
galactose-binding nodule lectin
- Fru
fructose
- MNL
mannosebinding nodule lectin
-
M
r
rerative molecular mass
- PBS
phosphate-buffered saline
- PSL
peanut seed lectin
- SDS
sodium dodecyl sulphate
- Sorb
sorbitol 相似文献
17.
The direct double-antibody enzymelinked immunosorbent assay system was used in the detection and measurement of seed lectins from peanut (Arachis hypogaea L.) and soybean (Glycine max L.) plants (PSL and SBL, respectively) that had been inoculated with their respective rhizobia. Concentrations of PSL dropped to undetectable levels in peanut roots at 9 d and stems and leaves at 27 d after planting; SBL could no longer be detected in soybean roots at 9 d and in stems and leaves at 12 d. A lectin antigenically similar to PSL was first detected in root nodules of peanuts at 21 d reaching a maximum of 8 g/g at 29 d then decreasing to 2.5 g/g at 60 d. There was no evidence of a corresponding lectin in soybean nodules.Sugar haemagglutination inhibition tests with neuraminidase-treated human blood cells established that PSL and the peanut nodule lectin were both galactose/lactose-specific. Further tests with rabbit blood cells demonstrated a second mannosespecific lectin in peanut nodule extracts that was not detected in root extracts of four-week-old inoculated plants or six-week-old uninoculated plants, although six-week-old root extracts from inoculated plants showed weak lectin activity. The root extracts from both nodulated and uninoculated plants contained another peanut lectin that agglutinated rabbit but not human blood cells. Haemagglutination by this lectin was, however, not inhibited by simple sugars but a glycoprotein, asialothyroglobulin, was effective in this respect.Abbreviations DAS
double antibody sandwich
- ELISA
enzyme-linked immunosorbent assay
- PBS
phosphate-buffered saline
- PSL
peanut seed lectin
- SBL
soybean lectin 相似文献
18.
Soybean lectin and related proteins in seeds and roots of le and le soybean varieties 总被引:2,自引:2,他引:0
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The localizations of soybean lectin (SBL) and antigenically related proteins in cotyledons and roots of lectin positive (Le+) and lectin negative (Le−) soybean cultivars were compared by light level immunocytochemistry using antibodies produced against the 120 kilodalton (kD) native seed lectin tetramer or its subunits. Lectin is present in the protein bodies of cotyledons cells as are two other seed proteins, the Kunitz trypsin inhibitor and the storage protein glycinin. Analysis of single seed extracts by immunoblotting of sodium dodecyl sulfate-polyacrylamide gels using the same antibodies, reveals up to 4 milligrams of the 30 kD seed lectin protein is present per seed in the Le+ varieties. There is no detectable lectin in the protein bodies of Le− cotyledons as determined by immunocytochemistry and immunoblotting. Enzyme-linked immunosorbent assay confirmed this result to a sensitivity of less than 20 nanograms per seed. In contrast, the roots of both Le+ and Le− plants bind the seed lectin antibody during immunocytochemistry, with fluorescence mainly localized in vacuole-like bodies in the epidermis. Root extracts contain a 33 kD polypeptide that binds anti-SBL antibody at an estimated minimal level of 20 nanograms per 4-day seedling, or 2.0 nanograms per primary root tip. This polypeptide is also present in the embryo axis and in leaves. The latter also contain a 26 kD species that binds seed lectin antibody. The 30 kD seed lectin subunit, however, is not detectable in roots or leaves. 相似文献
19.
In several studies plant lectins have shown promise as transgenic resistance factors against various insect pests. We have here shown that pea seed lectin is a potential candidate for use against pollen beetle, a serious pest of Brassica oilseeds. In feeding assays where pollen beetle larvae were fed oilseed rape anthers soaked in a 1% solution of pea lectin there was a reduction in survival of 84% compared to larvae on control treatment and the weight of surviving larvae was reduced by 79%. When a 10% solution of pea lectin was used all larvae were dead after 4 days of testing. To further evaluate the potential use of pea lectin, transgenic plants of oilseed rape (Brassica napus cv. Westar) were produced in which the pea lectin gene under control of the pollen-specific promoter Sta44-4 was introduced. In 11 out of 20 tested plants of the T0-generation there was a significant reduction in larval weight, which ranged up to 46% compared to the control. A small but significant reduction in larval survival rate was also observed. In the T2-generation significant weight reductions, with a maximum of 32%, were obtained in 10 out of 33 comparisons between transgenic plants and their controls. Pea lectin concentrations in anthers of transgenic T2-plants ranged up to 1.5% of total soluble protein. There was a negative correlation between lectin concentration and larval growth. Plants from test groups with significant differences in larval weights had a significantly higher mean pea lectin concentration, 0.64% compared to 0.15% for plants from test groups without effect on larval weight. These results support the conclusion that pea lectin is a promising resistance factor for use in Brassica oilseeds against pollen beetles. 相似文献
20.
Several studies have indicated that the capture of nematodes by the nematophagous fungus Arthrobotrys oligospora is mediated by a lectin on the fungal surface. One of the major surface proteins of this fungus showed haemagglutinating activity and was isolated by affinity chromatography using a mucin Sepharose column. Biochemical analysis showed that the protein was a dimeric glycoprotein with a molecular mass of 36 kDa and an isoelectric point of pH 6.5, and contained no sulphur amino acids. The protein was N-terminally blocked; four internal peptides were sequenced, and showed no significant similarity to sequences in the Swiss-Prot or PIR databases. The haemagglutinating activity of the isolated protein was not inhibited by any of the mono- or disaccharides tested, but it was inhibited by the glycoproteins fetuin and mucin. The haemagglutinating activity changed after incubating the protein in buffers of different pH, with maximal activity at pH 11.0 and no activity at pH 2.8. The lectin was tested for different enzymic activities but none were detected. Analysis of the haemagglutinating activity in various cell fractions indicated that the protein was associated with extracellular polymer layers and with the cell wall of the fungus. About the same amount of the haemagglutinating protein was recovered from samples of vegetative mycelium and of mycelium containing nematode-trapping cells. 相似文献