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PubMed1979

Phaseolus vulgaris isolectin binding to human erythrocytes.

The Phaseolus vulgaris isolectins L4,L3E1, L2E2, L1E3, and E4 were isolated by affinity and ion exchange chromatography. Pure isolectins were radiolabeled by the chloramine-T method with Na125IO4 and their binding to human erythrocytes was studied. A normal erythrocyte has approximately 8 times 10(5) receptor sites for each isolectin; however, the association constants (Ka) of binding increased from 1.1 times 10(7) M-1 to 3.8 times 10(8) M-1, with increasing number of E subunits per tetrameric isolectin molecule. Isolectin to erythrocyte binding reached equilibrium rapidly and was reversed by fetuin. All isolectins competed with 125I-E4 for erythrocyte binding sites, with a constant (KI) similar to the Ka calculated for each respective radiolabeled isolectin. When isolectin binding at 0 degrees C, 4 degrees C, or 8 degrees C was compared to that at 25 degrees C, there was no reduction in the number of binding sites per cell, but the Ka of E4 was reduced to 3 times 10(7) M-1. Fixed erythrocytes displayed similar isolectin binding characteristics.

Binding Sites↗
PubMed1975

Histochemical studies in stomatal apparatus of Phaseolus mungo Linn. I. Localization of enzymes and structural material.

In the present investigations, the localization of several enzymes (Acid Phosphatase, Peroxidase, succinic dehydrogenase, Phosphorylase, alkaline phosphatase, ATP-ase) and other substances in the guard and subsidiary cells as well as trichomes of the leaves of Phaseolus mungo, was carried out. Attempts were also made to follow the sequence of developmental stages starting with meristemoids and culminating in differentiated structures. The basic information thus obtained is used in interpreting the developmental physiology of stomatal differentiation as well as their cellular organisation. Histochemical observations made in the present studies are compared with the electron microscopical observations of Whatley (1972). It is proposed that mitochondria played a basic role in the functioning of the guard cells. The present studies also demonstrated activity of acid phosphatase in the guard cells and was localized in spherosomes. The latter varied in the activity for acid phosphatase and was dependent on the turgid level of the cell. Interestingly, enough localization of phosphatase could only be observed in spherosomes when the osmotic pressure in the cell was relatively low, once the osmotic pressure increased, the activity disappeared.

Acid Phosphatase↗
PubMed1975

Histochemical studies in stomatal apparatus of Phaseolus mungo linn. IV. Mechanism of stomatal action.

The histochemical studies were carried out in the open and closed stomata of Phaseolus mungo leaves. Several enzymes like, Acid phospatase peroxidase, succinic dehydrogenase, phosphorylase, alkaline phosphatase, ATP-ase etc. were localized in the guard and subsidiary cells of epidermal peel. On the basis of cytochemical localization, enzyme activity was precisely interpreted. In the light of fluctuations in the localization, activities of different enzymes, an attempt is made to provide the functional interpretation of stomatal mechanism. We have attempted to correlat our observations in relation to diurnal metabolisms. Our studies suggest that starch-sugar inter-changes played a vital role in the stomatal regulation. We are also inclined to believe that besides guard cells, subsidiary cells also influenced the turgid conditions. A model based on available facts in collaboration with our own studies is presented which tends to explain the stomatal regulation.

Acid Phosphatase↗
PubMed1977

[Purification and properties of the tetrahydropteroylglutamate methyltransferase from green beans (Phaseolus vulgaris) (author's transl)].

The tetrahydropteroylglutamate methyltransferase from green beans (Phaseolus vulgaris) has been purified 80-fold by ion exchange chromatography and gel filtration. Optimal methyl transfer is found at pH 6.5 and 39 degrees C. Even at 0 degrees C, however, a considerable catalytic rate is observed. The Michaelis-Menten constants for homocysteine and 5-methyltetrahydropteroylglutamate are 0.43mM and 2.4 mM, respectively. Magnesium ions enhance the activity. Even purified preparations appear to contain traces of magnesium ions firmly bound, since a residual activity is found without addition of magnesium salts. Though the reaction requires anaerobiosis, an excess of reducing agents is inhibitory. The molecular weight of the transferase, determined by gel filtration, is 40 000 +/- 6%.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1975

Purification and properties of phaseolamin, an inhibitor of alpha-amylase, from the kidney bean, Phaseolus vulgaris.

Kidney beans, Phaseolus vulgaris, contain a proteinaceous inhibitor of alpha-amylase, which we have named phaseolamin. The inhibitor has been purified to homogeneity by conventional protein fractionation methods involving heat treatment, dialysis, and chromatography on DEAE-cellulose, Sephadex G-100, and CM-cellulose. Phaseolamin is specific for animal alpha-amylases, having no activity towards the corresponding plant, bacterial, and fungal enzymes, or any other hydrolytic enzyme tested. Optimal inhibitory activity is expressed during preincubation of enzyme and inhibitor at pH 5.5 and 37 degrees. Substrate prevents inhibition. Measurement of the stoichiometry on inhibition showed that a 1:1 complex of alpha-amylase and inhibitor is formed. Complex formation was demonstrated by chromatography on Sephadex G-100. The phaseolamin-amylase complex is dissociated at low pH values, apparently as a result of destruction of the enzyme; the complex cannot be dissociated by other conditions unfavorable for inhibition (low temperature or high pH). Phaseolamin inhibits hog pancreatic alpha-amylase in a noncompetitive manner.

Amylases↗
PubMed1979

[Comparison of glutamate dehydrogenase and glutamine synthetase activities in the roots and aerial organs of an obligate halophyte: Suaeda maritima var. macrocarpa and a glycophyte: Phaseolus vulgaris, grown in presence of different concentration of NaCl].

The glutamate dehydrogenase and glutamine synthetase activities of an obligate halophyte, Suaeda maritima var. macrocarpa and a glycophyte. Phaseolus vulgaris are compared in function of salinity (increasing concentrations of NaCl) of the culturing solution. In culture, addition of NaCl stimulates glutamine synthetase activity and lowers glutamine dehydrogenase activity in the aerial organs and in the roots of Suaeda as opposed to what is observed in the glycophyte. Hence the obligatory halophily of Suaeda is related to an increase of the glutamine synthetase activity in a sal-trich medium corresponding to the stimulation of nitrate reductase and proteogenesis.

Glutamate Dehydrogenase↗
PubMed1979

Chloride localization in Phaseolus vulgaris leaves exposed to HCl gas.

An investigation of chloride accumulation and distribution in unifoliate leaves of Phaseolus vulgaris following supra-acute exposures to gaseous hydrogen chloride (HCl) was conducted. Plants which were 8-22 days old (post-seeding) were exposed for 20 min to HCl gas in concentrations ranging from 6.0-54.2 mg m-3 in different combinations of age and concentration. Aqueous extracts of treated unifoliates contained more chloride than was present in control leaves. In both 8 and 12-day-old leaves, the amount of chloride accumulated was proportional to the exposure concentration of HCl, but 12-day-old plants accumulated less chloride than 8-day-old plants. The number of leaves with macroscopic injury symptoms (epidermal glazing and interveinal necrosis) was also related to chloride content. Precipitation of chloride ions by silver salts was employed to examine the ultrastructural distribution of chloride. Deposits of AgCl were present in cell walls, ground plasm, vacuoles, and chloroplasts of both control and HCl-treated leaf tissues. In leaves sampled immediately after treatment, chloroplastic AgCl precipitates were less than in controls, but as sampling was delayed from the HCl treatment, AgCl deposits in chloroplasts regained control levels. The frequency and distribution of AgCl deposits indicated that chloride passed through the leaf cuticle and migrated through the apopolast. Chloride also entered the cytoplasm of cells and appeared to be sequestered in vacuoles of treated cells.

Cell Wall↗
PubMed1977

Histochemical studies in stomatal apparatus of Phaseolus mungo Linn, Lathyrus sativus Linn and Opuntia elatior Mill.

With histochemical methods the distribution of some enzymes and metabolic substances in the epidermal peelings of Phaseolus mungo, Lathyrus sativus, and Opuntia elatior under light and dark conditions is examined. Dehydrogenases oxidases, transferases and hydrolases were studied. Fluctuations in the activity of hydrolases, especially, acid phosphatase, lipase, glucose-6-phosphatase, adenosine triphosphatase, dehydrogenases and transferases were observed during light and dark conditions. The role of such fluctuations in relation to stomatal regulation is discussed. Based on the present studies the following is suggested; stomatal opening and closing is related to structural and metabolic changes, and these changes are brought about by sugar gradients in the guard cells; light is enhancing the synthesis of sugars and some hormones, and besides this it stimulates membrane bound adenyl cyclase and release of cyclic AMP which affects the permeability; subsidiary cells actively participate in the stomatal physiology. Lysosomal hydrolytic enzymes like acid phosphatase are actively involved in catabolic phase of normal guard cells metabolism and regulate the osmotic pressure of the guard cells.

Ascorbic Acid↗
PubMedDate not supplied

[Amino acid composition of Phaseolus aureus L. seeds and seedlings].

The amino acid composition of seeds and 10-day seedlings of mung bean (Phaseolus aureus L.) as well as that of proteins of Ph. aureus seedlings was measured. The seedlings were grown under different conditions of nitrogen nutrition in the light and in the dark. Ph. aureus seeds showed a high content of some essential amino acids. As compared with seeds, the seedlings had higher concentrations of aspartic acid and isoleucine and lower concentrations of glutamic acid, lysine and histidine. Proteins of Ph. aureus seedlings showed greater amounts of isoleucine, phenylalanine, threonine, lysine and lower quantities of glutamic acid. Methionine and cystine were limiting amino acids.

Amino Acids↗
PubMed1978

[Nutritional evaluation of protein concentrates of beans (Phaseolus vulgaris) and lentils (Lens esculenta)].

The composition and nutritive value were determined in navy bean meal (Phaseolus vulgaris) and lentil meal (Lens esculenta), and in their respective protein concentrates obtained through extraction followed by isoelectric precipitation. Sulfur amino acids per gram of nitrogen were lower in the concentrates than in the meals, while there was no difference for lysine and threonine. The white bean protein concentrate had a lower biological value than the meal but better digestibility, although trypsin inhibitor concentration was unchanged. Digestibility greatly improved with heating but it did not increase beyond 81% even after autoclaving. Autoclaved samples supplemented with methionine reached a biological value of 83. The lentil protein concentrate also had a lower biological value than the meal but digestibility was high for both samples (91%) and remained unchanged after heating. Trypsin inhibitors were absent. After supplementing with methionine, a biological value of only 63 was obtained, due to the low level of tryptophan, the second limiting amino acid. In spite of the concentrates' lower biological value, it was proved that they equalled the meals' potential for complementing cereal, as their content in lysine and threonine is high. The concentrates have the additional advantage of allowing effective supplementation without increasing the legume-cereal ratio.

Amino Acids, Essential↗
PubMed1978

[Effect of various heat treatments in the hemagglutinin content and in the protein quality of beans (Phaseolus vulgaris)].

The effect of pre-soaking raw seed beans upon detoxification and the biological quality of its protein were evaluated. In whole raw seed beans (Phaseolus vulgaris) var. "tórtola", the net protein utilization (NPU), true digestibility and hemagglutinin titer were determined after 60', 90' and 120' of heat treatment, with and without 14 hours of pre-soaking. It is concluded that soaking prior to cooking is not necessary to eliminate the toxicity of dry beans, but that it does contribute to the softening of seeds and reduction of cooking time. The hemagglutinin levels of six commercial bean flours were evaluated, concluding that almost all of them presented toxic levels. The effect of the cooking methods upon the toxicity of bean flours was studied. Two raw bean flours, var. "tórtola" and "burro" at 10% and 20%, were cooked employing different boiling times (5, 10, 15 and 30'). The two raw samples contained high hemagglutinin levels which were inactivated at 10% with 10' cooking. The presence of toxic levels was detected at 20% after 15' cooking and these were eliminated at 30' of cooking.

Agglutinins↗
PubMed1975

Histochemical studies in stomatal apparatus of Phaseolus mungo Linn. II. Localization of phosphorylase.

Using histochemical techniques the presence of phosphorylase in the guard cells and subsidiary cells of Phaseolus mungo leaf has been demonstrated. The intensity of reaction is intense in the material collected at night while during the day collected leaves, both chloroplastic and cytoplasmic starch was absent. The functional significance of chloroplastic starch in the subsidiary cells in relation to the stomatal mechanism is discussed.

Chloroplasts↗
PubMed1977

Recombinations of subunits of Phaseolus vulgaris isolectins.

Phaseolus vulgaris phytohemagglutinin is formed in vivo by the combination of erythrocyte (E)-reactive and lymphocyte (L)-reactive subunits into five tetrameric isolectins:L4,L3E1, L2E2, L1E3, and E4. Evidence for phytohemagglutinin subunit structure is obtained by in vitro dissociation of native isolectins in 6 M guanidine HCl followed by removal of dissociating agents to allow subunit recombination. Dissociation and recombination of L4 yielded a single protein, electrophoretically indistinguishable from the native L4. Similar treatment of E4 also yielded a single protein indistinguishable from native E4. Treatment of L3E1, L2E2, L1E3, or a mixture of L4 and E4, yielded five distinct proteins electrophoretically similar to all five native phytohemagglutinin isolectins. Milligram quantities of all five recombinant isolectins were prepared either from L2E2 or a mixture of L4 and L1E3 proportioned to yield equimolar quantitives of the two subunits on dissociation. The recombinant isolectins were purified by affinity and SP-Sephadex ion exchange chromatography. Electrophoretic and chromatographic properties and the erythroagglutinating and mitogenic activities of recombinant isolectins were essentially identical with the native isolectins. The inclusion of 125I-labeled L4 in the dissociation results in a distribution of 125I-labeled L subunit among the purified recombinant isolectins proportional to their proposed subunit structures.

Chemical Phenomena↗
PubMed1977

[Protein quality and hemagglutin content in tender and dried bean seeds (Phaseolus vulgaris) coscorrón variety].

Protein quality and hemagglutinating content in tender and dry seed beans: The chemical composition, hemagglutinating activity, protein queality (NPU10) and true digestibility of samples at three certified bean seeds (Phaseolus vulgaris) var coscorrón, tender and dry (recollected 90-95 days and 120-125 days after seeding respectively), were determined. The tender and dry seeds were submitted to usual cooking (tender equals 30' boiling and dry equals 90' boiling previously soaked for +/- 14 hours in water). The hemagglutinating activity in raw tender and dry seeds was similar. The hemagglutinating activity was completely destroyed by these treatments. The protein quality and digestibility of cooked tender and dry samples were similar (NPU10) equals 48,4 and 47,5; true digestibility 79,9 and 80,1 respectively). It is concluded that heat treatments used are adquate to eliminate the hemagglutinating activity and toxicity of the seeds. In relation to protein quality there is no nutritional advantage of consuming tender or dry beans.

Animals↗
PubMedDate not supplied

Circadian periodic response of Phaseolus vulgaris l. to 2,4-dichlorophenoxyacetic acid.

The susceptibility of bean plants, Phaseolus vulgaris L., cv. Executive, to 2,4-dichlorophentoxyacetic acid (2,4-D) appeared to depend upon the time of application. Oscillations in response to 2,4-D were evident in plants subjected to conditions of alternating light and dark spans, continuous illumination or darkness. The fresh and dry weight of plant material was generally less when 2,4-D was applied to plants near the later portions of the light span.

2,4-Dichlorophenoxyacetic Acid↗