An isoflavone diglycoside from the seeds of Dolichos biflorus

-5-Hydroxy-7,3′,4′-trimethoxy-8-methylisoflavone 5-neohesperidoside has been identified from the seeds of Dolichos biflorus.     

Development and Distribution of a Lectin from the Stems and Leaves of Dolichos biflorus

The stems and leaves of the Dolichos biflorus plant contain a lectin that cross-reacts with antiserum against the seed lectin. This cross-reactive material (CRM) was followed during early seedling growth, stem elongation, and seed development using a specific radioimmunoassay.

No CRM was detected in developing seeds, but very low levels were found in dormant and imbibed seeds. As germination proceeds, the CRM accumulates at the apex of both etiolated and green seedlings in the epicotyl and leaves. Lower amounts of CRM are found in the cotyledons and hypocotyl, but no CRM was detected in the roots.

The amount of CRM in the first and second stem internodes increases during elongation and gradually declines after the completion of elongation. Approximately 80% of the CRM in the stems of 19-day-old Dolichos biflorus plants is associated with the elongating tissues. These results are discussed with respect to the possible roles of lectins in plants.

     

A Bowman–Birk protease inhibitor with antifeedant and antifungal activity from Dolichos biflorus

In the present study, 11 varieties of Dolichos biflorus exhibited both protease inhibitor activities as well as in vitro inhibitory activity against Helicoverpa armigera gut protease. A Bowman–Birk protease inhibitor showing activity against trypsin and α-chymotrypsin has been purified from D. biflorus seeds using multi-step strategy. The purified inhibitor revealed a single band on SDS-PAGE corresponding to molecular mass of 16 kDa. The inhibitory constants for the interaction of purified PI with trypsin and α-chymotrypsin were 0.04 and 0.48 μM, respectively. The purified inhibitor was stable over a pH range of 2–12 and up to a temperature of 100 °C for 20 min. The results of insect bioassay against H. armigera revealed 68 % decline in larval weight after 7 days of feeding on artificial diet containing the inhibitor. The larval growth and % leaf area eaten were drastically reduced in the presence of inhibitor. The observed cumulative mortality from larval to adult was 51.21 %. The inhibitor displayed antifungal activity against Alternaria alternata, Fusarium oxysporum, and Aspergillus niger with minimum inhibitory concentration as 0.4, 0.6, and 1.2 μg mL^?1, respectively. This is the first report of anti-feedant and anti-fungal activities of D. biflorus protease inhibitor on a single protein, which might be important for developing transgenic plants resistant to insect pests and fungal pathogens.     

Electron microscopy of human erythrocytes agglutinated by lectin from Codium fragile ssp. tomentosoides and pseudo-haemagglutinin from Ascophyllum nodosum

Human erythrocytes were exposed to extracts of Codium fragile ssp. tomentosoides, Ascophyllum nodosum, Dolichos biflorus seeds and a solution of purified polyphenols from Ascophyllum nodosum. In each case the erythrocytes appeared to agglutinate. Agglutinates were examined by scanning electron microscopy. Photomicrographs of the erythrocytes exposed to lectin-containing extracts of C. fragile and D. biflorus showed the typical appearance of agglutinated cells. Photomicrographs of the erythrocytes exposed to the crude extract and purified polyphenols from A. nodosum were similar to each other, but quite different in appearance to erythrocytes agglutinated by the lectins from C. fragile and D. biflorus. This evidence adds further support to the contention that lectin presence recorded in brown algal extracts is largely due to ‘pseudoagglutination’ produced by polyphenols contained in these extracts.     

Development and Distribution of Dolichos biflorus Lectin as Measured by Radioimmunoassay

A radioimmunoassay, capable of detecting the Dolichos biflorus lectin at concentrations as low as 400 ng/ml, was developed and used to follow the distribution of this lectin in the plant during its life cycle.

The lectin was first detected in the seeds of the plant 27 days after flowering and rapidly attained the high level of lectin present in the mature seed. The lectin content of the plant is highest in the seeds and cotyledons and decreases as the storage materials of the cotyledons decrease.

A low but measurable amount of material that reacts with antibodies to the seed lectin was detected in the leaves, stems, and pods of the plant. This material gives a precipitin band of only partial identity to the seed lectin when tested in immunodiffusion against antiserum to the seed lectin.

No lectin was detected by the radioimmunoassay in the roots of the plant at any stage of development.

     

A Novel Antilithiatic Protein from Tribulus terrestris Having Cytoprotective Potency

Adhesion of calcium oxalate (CaOx) crystals to kidney cells is a key event in kidney stones associated with marked hyperoxaluria. As the propensity of stone recurrence and persistent side effects are not altered by surgical techniques available, phytotherapeutic agents could be useful as an adjuvant therapy. The present study is aimed at examining the antilithiatic potency of the protein biomolecules of Tribulus terrestris, a plant which is a common constituent of herbal marketed preparations to treat urolithiasis. Various biochemical methods with mass spectrometry were used to purify and characterize the purified protein. The protective potency of the protein was tested on the oxalate induced injury on renal epithelial cell lines (NRK 52E). An antilithiatic protein having molecular weight of ~ 60kDa was purified. This purified protein showed similarities with Carotenoid cleavage dioxygenase 7 (CCD7) of Arabidopsis thaliana after matching peptide mass fingerprints in MASCOT search engine. An EF hand domain was identified in CCD7 by SCAN PROSITE. Presence of an EF hand domain, a characteristic feature of calcium binding proteins and a role in the synthesis of retinol which is transported by retinol binding protein, a protein found in kidney stone matrix; of CCD7 support the role of TTP as an antilithiatic protein. The protective potency of TTP on NRK 52E was quite comparable to the aqueous extract of cystone. Our findings suggest that this purified protein biomolecule from Tribulus terrestris could open new vista in medical management of urolithiasis.     

In-vitro anti-inflammatory activity of serine protease inhibitor from Cassia siamea and Dolichos biflorus: A comparative study

Cassia siamea is a nonedible legume belonging to Fabaceae. The seed of C. siamea contains ~16% of protein. The study reports the biochemical characterization of purified novel serine protease inhibitor from seeds of C. siamea, aimed with assessing the anti-inflammatory activity. The seed extract was subjected to ammonium sulfate precipitation followed by fast protein liquid chromatography (FPLC)-anion exchange chromatography and affinity-chromatography to obtain a relative pure protease inhibitor. Thirty-fivefold purification with the specific activity of 250 U/mg of trypsin inhibitory unit was obtained. The characterization of protease inhibitor for optimum temperature, pH, and metal ions were measured using N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA) assay and casein zymogram. The C. siamea trypsin inhibitor (CsTI) has a relative molecular mass of 25.540 kDa. Purified CsTI and Dolichos biflorus were tested for anti-inflammatory efficacy against A549 and RAW264.7 cell lines. The inhibitory activity of both purified inhibitors are comparable and are potent toward anti-inflammatory activity. The purified inhibitor shows to be a promising candidate as anti-inflammatory agent by targeting the serine proteases.     

Studies of lectins XXXVI. Properties of some lectins prepared by affinity chromatography on O-glycosyl polyacrylamide gels

A number of lectins has been purified by affinity chromatography on O-glycosyl polyacrylamide gels. The lectins isolated (and the particular sugar ligands used in the affinity carriers) are as follows: Anguilla anguilla, serum (α-L-fucosyl-), Vicia cracca, seeds; Phaseolus lunatus, seeds; Glycine soja, seeds; Dolichos biflorus, seeds; Maclura pomifera, seeds; Sarothamnus scoparius, seeds; Helix pomatia, ablumin glands; Clitocybe nebularis, fruiting bodies (all $\text{N-}\text{acetyl}\text{-α-}\text{d}\text{-galactosaminyl-}$); Ricinus communis, seeds (β-lactosyl-); Onomis spinosa, root; Fomes fomentarius, fruiting bodies; Marasmius oreades, fruiting bodies (all $\text{α-}\text{d}\text{-galactosyl-}$), Canavalia ensiformis, seeds, (i.e., concanavalin A) ($\text{α-}\text{d}\text{-glucosyl-}$).Physicochemical properties of Glycine soja, Dolichos bifloras, Phaseolus lunatus, Helix pomatia and Ricinus communis lectins correponded well to properties of the preparations studied earlier by other workers. For the other purified lectins the essential physicochemical data (sedimentation coefficient, molecular weight, subunit composition, electrophoretic patterns, amino acid composition, carbohydrate content, isoelectric point) were established and their precipitating, hemagglutinating and mitogenic activities determined.     

Dolichins A and B,two pterocarpans from bacteria-treated leaves of Dolichos biflorus

Two minor isoflavonoids isolated from bacteria-inoculated leaves of Dolichos biflorus have been identified as the 6aR; 11aR; 2′S and 6aR; 11aR; 2′S isomers of 3,9-dihydroxy-10-2′-hydroxy-3′-methyl-3′-butenyl pterocarpan.     

Production of a Lectin in Tissue Cultures of Dolichos biflorus

Callus cultures have been produced from the epicotyl and leaves, hypocotyl, and roots of germinating Dolichos biflorus seeds. These cultures were initiated on media containing 2,4-dichlorophenoxyacetic acid and kinetin, transferred to media with increased amounts of these hormones, and then maintained on hormone-free media. Extracts of these cultures were examined by radioimmunoassays specific for the lectin from the seeds of this plant and for a lectin that is present only in the stems and leaves of the intact plant. Although the seed lectin was not detected in any cultures, the stem and leaf lectin was produced in those cultures grown on the hormone free media. Lectin isolated from these cultures had subunits identical in electrophoretic mobilities to the subunits from the lectin isolated from intact stems and leaves. Levels of this lectin decreased when the cells were transferred back to media containing hormones and increased again upon transfer to the hormone-free media. The absence of exogenous hormones and the production of lectin were also correlated with the rapid growth and greening of the cells. Immunofluorescence and immunocytochemical studies on sections of cultured cells indicated that the stem and leaf lectin is associated with the cytoplasm as well as the cell wall as has been found in previous studies on the subcellular localization of this lectin in the intact plant.     

Studies on lectins XL. O-glycosyl derivatives of spheron in affinity chromatography of lectins

Free monosaccharides can be used for direct glycosylation of Spheron, a spherical macroporous hydroxyyalkyl methacrylate-ethylene dimethacrylate copolymer, in a reaction that proceeds at room temperature in dioxane medium under catalysis of dry HCl or BF₃. Derivatives of L-fucose, D-galactose, D-glucose, D-mannose, $\text{N-}\text{acetyl}\text{-}\text{D}\text{-}\text{galactosamine}$ and $\text{N-}\text{acetyl}\text{-}\text{D}\text{-}\text{glucosamine}$ thus prepared from Spheron beads have been shown to be efficient affinity carriers in isolation of lectins from seeds of Canavalia ensiformis D.C. (concanavalin A), Dolichos biflorus L., Glycine soja (L.) Sieb. et Zucc., Lens esculenta Moench, Ricinus communis L., Ulex europaeus L. and from albumin glands of the garden snail Helix pomatia L.     

The effect of periodate oxidation and α-mannosidase treatment of Dolichos biflorus lectin

The effects of periodate and α-mannosidase treatment of the Dolichos biflorus lectin were determined. Destruction by periodate of 16% of the mannose residues of the lactin had no effect on its ability to agglutinate type A erythrocytes, precipitate blood group A + H substance or to be precipitated by concanavalin A. Removal of up to 40% of the mannose by either periodate or α-mannosidase rendered the lecton nonprecipitable by concanavalin A. The lectrin treated by α-mannosidase retained its ability to agglutinate erythrocytes and precipitate blood group A + H substance, but the lectin treated with periodate lost most of its activity.The results suggest that the complete integrity of the carbohydrate unit of the lectin is not necessary for its activity and that the periodate may be affecting the protein portion of the molecule as well as its carbohydrate residues. No conversion of form A to form B of the lectin was observed with either periodate oxidation or α-mannosidase treatment.     

Diuretic and antilithiasic activities of ethanolic extract from Piper amalago (Piperaceae)

ObjectivePiper amalago is used in Brazilian folk medicine as diuretic and for the treatment of urinary calculus disease, although no scientific data have been described to support these effects. Thus, this study aims to evaluate the diuretic effects and antilithiatic activity of the ethanolic extract of P. amalago (EEPam).Materials and methodsEthanolic extracts of P. amalago (125, 250 and 500 mg/kg) were orally administered in male Wistar rats (n = 5) and urinary excretion was measured at intervals of up to 24 h after administration. The antilithiasic effect of EEPam on calcium oxalate urolithiasis crystallization was examined in a turbidimetric model.ResultsThe oral administration of all doses of EEPam significantly increased urine output after 24 h when compared to control group. Moreover, the application of EEPam, induced an inhibitory effect on calcium oxalate crystallization.ConclusionsAccording to results, P. amalago extracts showed diuretic and natriuretic activity and antilithiasic effects.     

An unusual allantoinase from Dolichos biflorus

An unusual allantoinase from Dolichos biflorus has been purified 62-fold. The purified enzyme has an unusual pH activity profile with a shoulder at pH 4 and a peak at pH 7.5. This is due to a single enzyme which does not need metal ions for activation. In the fully reduced state the enzyme exhibits a single sharp peak at 7.5; when it is not in the sulfhydryl form (in the fully oxidized SS form?) the enzyme shows a single pH optimum at pH 4. K_m values for (±)-allantoin were 5.5 mM at pH 4 and 1.43 mM at pH 7.5. Allantoinase activity has been demonstrated in the resting seed, and increased linearly with time during the first 5 days of seedling growth.     

Spermatogonia-specific proteins expressed in prepubertal buffalo (Bubalus bubalis) testis and their utilization for isolation and in vitro cultivation of spermatogonia

Buffalo is an economically important livestock species in Asia. Little is known about male germ line technology owing to lack of sufficient understanding regarding expression of germ- and somatic-cell specific-proteins in the testis. In this study, we identified UCHL-1 (PGP 9.5) and lectin- Dolichos biflorus agglutinin (DBA) as specific markers for spermatogonia in buffalo testis. Expression of germ-cell and pluripotency-specific proteins such as DDX4 (VASA) and POU5F1 (OCT3/4) were also present in spermatogonia. Interestingly, the expression of somatic cell-specific proteins such as VIMENTIN and GATA4 were also detected in germ cells. Using two-step enzymatic digestion followed by differential plating and Percoll density-gradient centrifugation, an approximately 55% spermatogonia-enriched cell population could be obtained from the prepubertal buffalo testis. Isolated spermatogonia could survive and proliferate in vitro in DMEM/F12 medium containing 10% fetal bovine serum in the absence of any specific growth factors for a week. Cultured spermatogonia showed DBA affinity and expressed DDX4 and POU5F1. These results may help to establish a long-term culture system for buffalo spermatogonia.     

Interaction between Dolichos biflorus lectin and chick embryonic fibroblasts at different stages of development

The interaction between chick embryo fibroblasts and A1-specific blood group Dolichos biflorus lectin has been studied at various stages of embryo development. The site number (($\text{0.26±0.03) · 10}{}^6\text{sites/cell}$) remains the same during development whereas the affinity constant apparently decreases from 8-day cells onwards. The effects of cell number, temperature and time course on the Dolichos binding to fibroblasts were not age dependent. Competitive binding experiments revealed that Dolichos receptor sites were distinct from binding sites of Robina pseudoacacia lectin and concanavalin A, but partially related to binding sites of Ricinus lectin. Thymidine incorporation by fibroblasts in the presence of Dolichos lectin was age dependent. It was inhibited in 6-day cells and weakly stimulated in 16-day cells, but not modified in 12-day cells. Dolichos lectin effects on embryo fibroblasts were very specific because both binding to cells and effect on thymidine incorporation were blocked by $\text{N-}\text{acetylgalactosamine}$, the determinant of Dolichos lectin, as well as by Dolichos antiserum.     

Organ-related differences in binding of Dolichos biflorus agglutinin to vascular endothelium

We screened cryostat sections of tissues from 10 inbred strains of mice with a panel of conjugated lectins, in a search for polymorphisms which could be used as markers in mouse chimeras. In DDK and RIII mice, but not the other strains tested, there are binding sites on the membrane of vascular endothelial cells for Dolichos biflorus agglutinin (DBA), which is specific for terminal nonreducing N-acetyl galactosamine residues. The expression of DBA binding sites on RIII and DDK endothelium is not, however, uniform: there are consistent differences between blood vessels in different organs. These observations provide evidence of an organ-related heterogeneity in vascular endothelium which is open to biochemical analysis, and which raises the possibility that endothelial cells carry a “tissue address.”     

The reactivity of canine red cells with heterophile agglutinins having anti-A activity*

Heterophile A-reactive agglutinins, obtained from the seeds of Dolichos biflorus and from the snails Helix aspersa, Helix pomatia and Cepaea nemoralis, were tested for reactivity with the saliva and red cells of a random series of dogs. Saliva from dogs with the A-like Tr red cell antigen inhibited the agglutination of human A red cells by each of the reagents. However, none of the heterophile agglutinins distinguished Tr+ from Tr— red cells: the Dolichos agglutinin was non-reactive, while all of the snail reagents agglutinated both Tr+ and Tr— cells. It is concluded that the canine red cell bears a series of heterophile receptors which mask reactivity with the canine homologue of the red cell A-antigen, and that the restricted size of the binding sites of the agglutinins limits the informational significance of cross-reactivity obtained with these reagents.     

A Nod factor-binding lectin is a member of a distinct class of apyrases that may be unique to the legumes

Recent studies from our laboratory have found that a root lectin from the legume Dolichos biflorus is present on the root surface, binds rhizobial Nod factor and has apyrase activity. To assess the broader significance of this lectin/nucleotide phosphohydrolase (Db-LNP), we have cloned a second related cDNA (Db-apyrase-2) from D. biflorus, as well as related cDNAs from the legumes Lotus japonicus and Medicago sativa, and from Arabidopsis thaliana, a non-legume. The deduced amino acid sequences of these apyrases were aligned with one another and with the sequences of other apyrases from plants, animals, yeast and protozoa. Phylogenetic analysis shows that Db-LNP has closely related orthologs only in other legumes, while Db-apyrase-2 is more closely related to apyrase sequences from non-leguminous plants. We also show that the orthologs of Db-LNP from M. sativa and Pisum sativum have carbohydrate binding activity. The results suggest that legume LNPs may represent a special class of apyrases that arose by gene duplication and subsequent specialization. Received: 11 March 1999 / Accepted: 14 June 1999