High Content Of Aspartic Acid Research Articles

Nutritional characteristics and antiradical activity of turmeric (Curcuma longa L.), beetroot (Beta vulgaris L.), and carrot (Daucus carota L.) grown in Bangladesh

Curcuma longa L. (turmeric), Beta vulgaris L. (beetroot), and Daucus carota L. (carrot) grown in Bangladesh were analyzed for nutritional and phytochemical contents to reveal their comparative nutritional compositions and antiradical properties. Ash, protein, and carbohydrate content were significantly preeminent in beetroot as compared to others. Whereas fat content was found to be high in turmeric, carrots contained a great percentage of crude fiber. Beetroot was shown to have much greater potassium, calcium, and iron levels than others. Regarding amino acids, glutamic acid was found to be greater in beetroot and carrot whereas turmeric had significantly high aspartic acid content. Leucine had the highest concentration among essential amino acids in these three samples. Total antioxidant activity, total flavonoids, and phenolic contents in the methanolic extract of turmeric were found to be substantially higher than in beetroot and carrot. Furthermore, the extract of turmeric (IC50 value: 13.46 μg/mL) scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) free radicals considerably to a greater extent than beetroot (IC50 value: 380.61 μg/mL) and carrot (IC50 value: 1252.85 μg/mL). A positive correlation was found between the phytochemical contents and antiradical activity. The information from this study will help to find the potential ingredients from these plants for functional food.

Free Amino Acids in Vegetative Organs of Picea obovata L. and Pinus sylvestris L.

It was shown that the changes in the phenological stages of tree development, associated with the loss of frost resistance and the onset of the growing season, were accompanied by significant changes in free amino acid composition in the meristematic tissues of Picea obovata L. and Pinus sylvestris L. buds. In winter, in both species, the level of nonproteingeneous amino acids was doubled in comparison with spring. At the same time, P. obovata and P. sylvestris showed significant species-specific differences in the total content of nonproteaginous amino acids. At P. sylvestris their share in the composition of free amino acids reached 40%, which was twice as high as that of P. obovata. In the free amino acids in P. obovata and P. sylvestris, the nitrogen reserve was mainly in the form of glycine corresponding to 13 and 9%, arginine, 12 and 8%, and ornithine, 12 and 15%, respectively. In addition, in P. sylvestris an important role in the nitrogen storage was played by γ- aminobutyric acid, about 19%, and valine, about 6%; in P. obovata this role was played by lysine and glutamic acid, about 10%. At the same time, the content of proline (an amino acid, which, generally, coordinates the high−low-temperature resistance of plants) in low-resistance coniferous species was low at about 0.04–0.34%. In spring, with bud swelling in both species, the share of arginine and proline increased, and the share of ornithine and γ-aminobutyric acid sharply decreased. In addition to these amino acids, the lysine content in P. obovata was doubled. In spring, for P. sylvestris a high content of aspartic acid and asparagine of about 19% was characteristic, for P. obovata the content of amino acids with a short carbon chain (the total amount of serine + glycine) rose to 22%. As a reliable stress metabolite in both species, one may consider ornithine, whose content in bud meristems in winter was 3–5 times higher than in the meristems of swollen buds in spring.

On the Origin of Sequence.

Three aspects which make planet Earth special, and which must be taken in consideration with respect to the emergence of peptides, are the mineralogical composition, the Moon which is in the same size class, and the triple environment consisting of ocean, atmosphere, and continent. GlyGly is a remarkable peptide because it stimulates peptide bond formation in the Salt-Induced Peptide Formation reaction. The role glycine and aspartic acid play in the active site of RNA polymerase is remarkable too. GlyGly might have been the original product of coded peptide synthesis because of its importance in stimulating the production of oligopeptides with a high aspartic acid content, which protected small RNA molecules by binding Mg2+ ions. The feedback loop, which is closed by having RNA molecules producing GlyGly, is proposed as the essential element fundamental to life. Having this system running, longer sequences could evolve, gradually solving the problem of error catastrophe. The basic structure of the standard genetic code (8 fourfold degenerate codon boxes and 8 split codon boxes) is an example of the way information concerning the emergence of life is frozen in the biological constitution of organisms: the structure of the code contains historical information.

Purification and characterization of cysteine protease from germinating cotyledons of horse gram

BackgroundProteolytic enzymes play central role in the biochemical mechanism of germination and intricately involved in many aspects of plant physiology and development. To study the mechanism of protein mobilization, undertaken the task of purifying and characterizing proteases, which occur transiently in germinating seeds of horse gram.ResultsCysteine protease (CPRHG) was purified to homogeneity with 118 fold by four step procedure comprising Crude extract, (NH4)2SO4 fractionation, DEAE-Cellulose and CM-sephacel chromatography from the 2 day germinating cotyledons of horse gram (Macrotyloma uniflorum (Lam.) Verdc.). CPRHG is a monomer with molecular mass of 30 k Da, was determined by SDS-PAGE and gel filtration. The purified enzyme on IEF showed two isoforms having pI values of 5.85 and 6.1. CPRHG composed of high content of aspartic acid, glutamic acid and serine. The enzyme activity was completely inhibited by pCMB, iodoacetate and DEPC indicating cysteine and histidine residues at the active site. However, on addition of sulfhydryl reagents (cysteine, dithiothreitol, glutathione and beta-ME) reverse the strong inhibition by pCMB. The enzyme is fairly stable toward pH and temperature. Immunoblot analysis shows that the enzyme synthesized as zymogen (preproenzyme with 81 kDa) and processed to a 40 kDa proenzyme which was further degraded to give 30 kDa active enzyme.ConclusionIt appears that the newly synthesized protease is inactive, and activation takes place during germination. CPRHG has a broad substrate specificity and stability in pH, temperature, etc. therefore, this protease may turn out to be an efficient choice for the pharmaceutical, medicinal, food, and biotechnology industry.

Analysis of Proteinaceous Components of the Organic Matrix of Endoskeletal Sclerites from the Alcyonarian Lobophytum crassum

The mesoglea of alcyonarians is occupied by an abundance of minute calcitic sclerites. The sclerites of the alcyonarian Lobophytum crassum contain a water-soluble organic matrix comprising 0.48% of the sclerite weight and a water-insoluble fraction comprising 1.15% of the sclerite weight. Analysis of proteinaceous components in the soluble fraction shows a particularly high content of aspartic acid, followed by alanine, glycine, and glutamate. Aspartic acid, glycine, alanine, and glutamate are the most abundant residues in the insoluble fraction. In both cases, the fractions show the highest concentration of aspartic acid from the total proteins. In an in vitro assay, we show that the matrix proteins extracted from the calcitic sclerites induce the formation of amorphous calcium carbonate prior to its transformation into the calcitic crystalline form. We also show scanning electron micrographs of the rhombohedral calcite crystals used as template, the protein imprinted with these crystals. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of both matrices shows the protein fractions at 67 and 48 kDa. The soluble matrix shows two additional faint bands. Both fractions stain for a carbohydrate at 67 kDa, indicating a glycoprotein at this molecular weight. A newly derived protein sequence was subjected to bioinformatics analysis involving identification of similarities to other acidic proteins. The identification of these proteins in alcyonarian endoskeletal sclerites emphasizes the fundamental importance of such acidic proteins and sheds more light on the functions of these proteins in the processes of biocalcification.

Growth characteristics and dynamics of protein synthesis in callus cultures from Glycine wightii (Wight & Arn.) Verdc.

Cotyledon explants were first cultured on MS medium supplemented with 4.52 M 2,4-D and 0.46 mM kinetin. The development of the calli was followed (0, 4, 8, 12, 16, 20, 24, 28 and 32 days after) and the growth curve was determined, based in fresh and dry weight. The growth curve presented sigmoidal form with four distinct phases. The highest growth percentage was observed at the exponential phase and the lowest at the stationary phase. These results indicated that cotyledon callus subculture should be performed 20 days after inoculation. The calli obtained after a period of 28 days were freeze dried, macerated and submitted to extraction with buffers of different pH values (2.6; 4.0; 6.0; 8.0 and 10.0) and the proteins in the extracts were determined by Bradford method. The pH 8.0 buffer was the most efficient to extract the largest amount of protein. The amino acid analyses calli showed a high content of aspartic acid and low content of metionin. The dynamics of protein synthesis in calli was followed by SDS-PAGE electrophoresis.

Phosphorylation of Phosphophoryn Is Crucial for Its Function as a Mediator of Biomineralization

Phosphoproteins of the organic matrix of bone and dentin have been implicated as regulators of the nucleation and growth of the inorganic Ca-P crystals of vertebrate bones and teeth. One such protein identified in the dentin matrix is phosphophoryn (PP). It is highly acidic in nature because of a high content of aspartic acid and phosphate groups on serines. The 244-residue carboxyl-terminal domain of rat PP, predominantly containing the aspartic acid-serine repeats, has been cloned, and the corresponding protein has been expressed recombinantly in Escherichia coli. This portion of PP, named DMP2 (dentin matrix protein 2), is not phosphorylated by the bacteria and thus provided a means to study the function of the phosphate groups, the major post-translational modification of native PP. The recombinant DMP2 (rDMP2) possessed much lower calcium binding capacity than native PP. Small angle x-ray scattering experiments demonstrated that PP folds to a compact globular structure upon calcium binding, whereas rDMP2 maintained an unfolded structure. In vitro nucleation experiments showed that PP could nucleate plate-like apatite crystals in pseudophysiological buffer, whereas rDMP2 failed to mediate the transformation of amorphous calcium phosphate to apatite crystals under the same experimental conditions. Collagen binding experiments demonstrated that PP favors the formation of collagen aggregates, whereas in the presence of rDMP2 thin fibrils are formed. Overall these results suggested that the phosphate moieties in phosphophoryn are important for its function as a mediator of dentin biomineralization.

Isolation and partial characterization of a lectin from Bauhinia pentandra (bong) vog. Ex. Steua.

Bauhinia pentandra (Bong) Vog. ex. Steua seeds were investigated with respect to phenologic aspects (size, mass, hilum and length) and with respect to their chemical composition. The total nitrogen content of the seed flour was determined, and the flour was extracted in different pH values. A lectin was isolated from the seeds by Sepharose-4B affinity chromatography. The homogeneity of the lectin was demonstrated by SDS-PAGE in the presence of beta-mercaptoethanol. Only one protein band with an apparent molecular mass of 30 kDa was found. The B. pentandra lectin showed a carbohydrate specificity for D-galactose, a requirement for divalent metal cations (Ca2+ and Mn2+) for full activity and amino acid composition with a high content of aspartic acid, glutamic acid and alanine and low levels of methionine, cysteine and tryptophan. The lectin agglutinated rabbit and human A group erythrocytes and was relatively stable to heat treatment, retaining half of its original activity after 60 min at 70 ºC.

Effect of water soluble extract of nacre (Pinctada maxima) on alkaline phosphatase activity and Bcl-2 expression in primary cultured osteoblasts from neonatal rat calvaria.

The nacre (mother of pearl) layer of the oyster Pinctada maxima shell can initiate bone formation by human osteoblasts in vivo and in vitro and is a new biomaterial that induces osteogenesis. This activity of nacre could be due to its water-soluble matrix. We examined the action of a water-soluble extract of nacre on the osteoblast phenotype of cells isolated from rat neonatal calvaria by measuring alkaline phosphatase (ALP) activity and by localization of the anti-apoptotic protein Bcl-2 by immunocytochemistry. ALP activity was increased 7% (p<0.001) by 100 microg proteins/ml extract and 20% (p<0.001) by 50 microg proteins/ml extract, but a low concentration of extract decreased the ALP activity by 8%. Cells treated with a high aspartic acid content fraction of the extract had increased ALP activity (23%, p<0.0001). Nacre extract and the fraction have no effect on the proliferation of mature osteoblasts. Immunoreactive Bcl-2 was overproduced in the cytoplasm and nuclei of osteoblasts at all stages of culture. Bcl-2 was found over the whole chromatin in quiescent and mitotic cells at the end of mitosis in the two nuclei in one cell, before cytodieresis. Bcl-2 was also found over chromosomes. Thus, nacre extract stimulates Bcl-2 production in osteoblasts, that is correlated with the cell cycle. Bcl-2 was also abundant in the nucleoli of extract-treated cells. Thus, the concentration and subcellular distribution of Bcl-2 in osteoblasts in primary cultures is influenced by nacre extract, and related to the cell cycle and the regulation of gene expression. Hence, knowledge of how water-soluble extracts of Pinctada maxima nacre act on osteoblasts in vitro may reveal the mechanisms involved in its action in vivo on bone cells and bone regeneration.

Giant hornet ( Vespa mandarinia) venomous phospholipases : The purification, characterization and inhibitory properties by biscoclaurine alkaloids

Two species of giant hornet phospholipase B (PLB), α and β, were purified from the venom of Vespa mandarinia. The purification procedure was simplified by two steps of column chromatographies, Sephadex G-100 and SP-Sepharose. The molecular sizes of PLB α and β were 29.5 and 26.0 kDa, respectively. The isoelectric point of α and β enzymes were pH 10.6 and 10.7, respectively. The temperature optimum for egg yolk lecithin was a broad peak at 40–60°C for both enzymes. Amino acid compositions of both enzymes were high contents of aspartic acid, glycine, leucine, lysine and other aliphatic amino acids. Cystine was similar amounts to other species of phospholipases (PLs). The K m values of α and β enzymes were 8.29 and 7.53 mg/ml for egg yolk lecithin, respectively. In the catalytic specificity for L-α-phosphatidylcholine-β-oleoil-γ-palmitoil, the K m values of α enzyme for γ-palmitoil and β-oleoil residues were 0.528 and 1.392 mM, respectively. While the K m values of β enzyme for γ-palmitoil and β-oleoil residues were 7.91 and 2.68 mM, respectively. Both α and β enzymes were inhibited strongly by cepharanthine. The lecithin hydrolysis of α enzyme was competitively inhibited, but β enzyme was uncompetitive. Cepharanthine also inhibited noncompetitively PLA 2s of bovine pancreas, bee venom and Naja mossambica mossambica.

Functional Mimicry of Protein A of Staphylococcus aureus by a Proteolytically Cleaved Fragment

Protein A (PA) of Staphylococcus aureus has an array of biological functions, such as antitumor, antitoxic, anticarcinogenic, immunomodulatory, antifungal, and antiparasitic properties. We have already established that a theoretical trypsin-digested peptide fragment of protein A (20-mer) mimics immunomodulatory and IgG binding property of PA. In the present report we have concentrated on a 16-mer chymotryptic fragment of protein A, which has a sequence of 13 amino acids in common with the previously studied 20-mer peptide. Molecular modeling study qualitatively predicted that both 20-mer and 16-mer peptides retain Fc binding ability from an interaction energy point of view. In the present study our aim was to understand whether this theoretically predicted 16-mer chymotryptic fragment could be formed in a real experiment and also to understand its biological activities. Chymotrypsin cleavage of PA at 37°C for 24 h produced four major fragments on reverse-phase HPLC. The amino acid analyses of each fragment show the absence of cysteine residue from all fragments, which justifies the absence of cysteine in PA. We also observed high content of aspartic acid and glutamic acid residues in all fragments. On gel-filtration chromatography the chymotrypsin cleavage of PA shows five peaks, one of which overlaps with our theoretically selected 16-mer peptide on superimposition. We verified the IgG binding capacity of 16-mer peptide by capillary electrophoresis. The 16-mer peptide also induces the production of TNFα and IL-1α in serum of mice. The above observations suggest that the 16-mer peptide may be produced by chymotrypsin cleavage and also that this peptide possesses some of the major biological properties of PA, such as IgG binding, TNFα and IL-1α elicitation, etc.

Purification and properties of three cellobiases from Aspergillus niger A20.

Three cellobiases, here called cellobiase A, B, and C, from the culture filtrate of Aspergillus niger A20, were purified by precipitation with ammonium sulphate, gel filtration through Sephadex G-75, and column chromatography of DEAE-cellulose. The purified enzymes were homogeneous on polyacrylamide disk electrophoresis. The mol wt of the purified enzymes were estimated by SDS-gel electrophoresis to be 88,000, 80,000, and 71,000 for cellobiases A, B, and C, respectively. The enzymes were active at pH 4.5 and 55-60 degrees C. The pattern of their amino acid compositions showed high contents of aspartic acid, glutamic acid, threonine, serine, and glycine. The apparent K(m) values for cellobiose were 0.9, 1.63, and 1.0 mM for cellobiases A, B, and C, respectively. Calcium ions stimulated cellobiases B and C, and Co2+ and Mg2+ ions stimulated cellobiase A. The purified enzymes hydrolyzed cellobiose and aryl-beta-D-glucosides, but they had no action on sucrose, maltose, and cellulose. The three cellobiases catalyzed transglycosylase reaction, and the major product formed from cellobiose was tetramer of glucose.

The complete amino acid sequence of a trypsin inhibitor from Bauhinia variegata var. candida seeds.

Trypsin inhibitors of two varieties of Bauhinia variegata seeds have been isolated and characterized. Bauhinia variegata candida trypsin inhibitor (BvcTI) and B. variegata lilac trypsin inhibitor (BvlTI) are proteins with Mr of about 20,000 without free sulfhydryl groups. Amino acid analysis shows a high content of aspartic acid, glutamic acid, serine, and glycine, and a low content of histidine, tyrosine, methionine, and lysine in both inhibitors. Isoelectric focusing for both varieties detected three isoforms (pI 4.85, 5.00, and 5.15), which were resolved by HPLC procedure. The trypsin inhibitors show Ki values of 6.9 and 1.2 nM for BvcTI and BvlTI, respectively. The N-terminal sequences of the three trypsin inhibitor isoforms from both varieties of Bauhinia variegata and the complete amino acid sequence of B. variegata var. candida L. trypsin inhibitor isoform 3 (BvcTI-3) are presented. The sequences have been determined by automated Edman degradation of the reduced and carboxymethylated proteins of the peptides resulting from Staphylococcus aureus protease and trypsin digestion. BvcTI-3 is composed of 167 residues and has a calculated molecular mass of 18,529. Homology studies with other trypsin inhibitors show that BvcTI-3 belongs to the Kunitz family. The putative active site encompasses Arg (63)-Ile (64).

A new high molecular weight agglutinin from garlic (Allium sativum).

Erythrocyte agglutination by lectins from Allium sativum was inhibited only by mannose of the sugars tested. However, asialofetuin was more effective inhibitor of agglutination as compared to mannose. This led to the use of an asialofetuin-silica affinity column to isolate agglutinins of 110 and 25 kDa (ASA110 and ASA25). While ASA25 is a dimeric protein comprising of subunits of 12.5 and 13.0 kDa, ASA110 is a glycoprotein of two identical subunits of 47 kDa. ASA110 revealed to have a high content of aspartic acid, glycine, leucine and serine but low content of cysteine and methionine. It contains 14 residues of neutral sugars in addition to 43 residues of hexosamines per mole of lectin and requires metal ions for its functional conformation. Serological cross-reactions with other species showed some common epitopes of ASA110 and ASA25 present in A. porrum, A. ascalonicum, Narcissus alba, PHA and Con A but not in A. cepa. ASA110 with CHO cells indicated it to be weakly cytotoxic with LD50 of 160 microg/ml.

Purification of a noncollagenous high molecular weight protein from bovine articular cartilage.

A noncollagenous high molecular weight protein (HMW) was isolated from bovine articular cartilage by CsCl density gradient centrifugation followed by DEAE-cellulose chromatography and gel filtration chromatography. The molecular weight was estimated to be 320 kDa and the reduced HMW had a molecular weight of 105 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The amino acid composition of HMW showed a high content of aspartic acid, but no hydroxylysine and hydroxyproline were detected, indicating that the protein was not a collagen. Affinity purified rabbit antibody against HMW reacted specifically with HMW, but there was no immunoreaction with cartilage-specific proteoglycan, type II collagen and type I collagen. HMW showed dose-dependent attachment to types I, II, III and V collagens. However, HMW did not bind to fibronectin, decorin and heparin. Furthermore, the binding of HMW to heat-denatured collagens was lower than native collagens. In these observation, HMW may be recognized the triple helix structure of collagen for the interaction.

N-Terminal Sequence of a Core Protein from a Biglycan Isolated from Bovine Aorta

A biglycan was isolated from bovine aorta intima media by 4M guanidine HCl extraction of the tissue; the material was fractionated and purified by using isopycnic ultracentrifugation and DEAE Sephacel ion-exchange chromatography. Core proteins, resulting from digestion of the proteoglycan preparation with chondroitinase ABC, were resolved by SDS-polyacrylamide gel electrophoresis into three bands. The apparent molecular weight of the fast migrating major protein band was 47 kDa and the other slow-moving minor protein bands were 90 and 105 kDa. These proteins were recognized by a monoclonal anti-proteoglycan deltaDi-6S (MAb 3-B-3/Cl). The amino acid composition of 47 kDa core protein revealed a high content of aspartic acid, glutamic acid and leucine, similar to those found for biglycans isolated from bovine cartilage, rat vascular smooth muscle cell culture and human bone. The N-terminal sequence of 47 kDa core protein was determined as Asp-Glu-Glu-Ala-X-Gly-Ala-Glu-Thr-Thr-X-Gly-Ile-Pro-Asp which is identical to the sequence of bovine articular cartilage biglycan. The proteoglycan had two glycosaminoglycan chains.

Cartilage matrix proteins. An acidic oligomeric protein (COMP) detected only in cartilage.

An Mr = 524,000 oligomeric protein was isolated from bovine cartilage and designated COMP (Cartilage Oligomeric Matrix Protein). The protein is composed of disulfide-bonded subunits with an apparent Mr of 100,000 each. It is markedly anionic, probably due to its high contents of aspartic acid and glutamic acid, as well as to its substitution with negatively charged carbohydrates. COMP was found in all cartilages analyzed, but could not be detected in other tissues by enzyme-linked immunosorbent assay of guanidine HCl extracts. Within a given cartilage, COMP shows a preferential localization to the territorial matrix surrounding the chondrocytes.

PURIFICATION AND PARTIAL CHARACTERIZATION OF A LECTIN FROM THE SEEDS OF DIOCLEA GUIANENSIS

A lectin was purified from seeds of Dioclea guianensis by Sephadex G-50 affinity chromatography. Apparent homogeneity of the lectin was demonstrated by native polyacrylamide gel electrophoresis, chromatography on DEAE- and CM-Sepharose, and immunochemistry. The lectin showed a carbohydrate specificity for D-mannose (D-glucose)-binding, had a requirement for Ca−2 and Mn−2, contained no covalently bound carbohydrate and had an amino acid composition characterized by high content of aspartic acid, serine and threonine, and low levels of sulfur-containing amino acids. At pH 7.5 it exists as two species of molecular weight about 100 and 47 kD and in dissociating solvents three subunits of approximate size of 30, 18 and 12 kD were obtained. The lectin agglutinated erythocytes from rabbit and chicken but not from human, cow, sheep, goat or pig and was toxic to brine shrimp (Artemia salina) larvae. It was relatively heat-stable, retaining half of its original activity even after 90 min at 70°C.

Purification and characterization of a small dermatan sulphate proteoglycan implicated in the dilatation of the rat uterine cervix.

A small dermatan sulphate proteoglycan (DSPG) was extracted from rat cervices and was purified by using DEAE-Sephacel ion-exchange chromatography, gel filtration on Sepharose CL-2B and CsCl-density-gradient centrifugation. Sedimentation-equilibrium centrifugation gave a weight-average Mr of 95,000. Amino acid analysis showed a high content of aspartic acid, glutamic acid, glycine and leucine. The glycosaminoglycan chains had Mr 50,000 as determined by gel filtration. Chondroitin AC lyase and chondroitin ABC lyase digestions of these chains showed that they were composed of 75% dermatan sulphate and 25% chondroitin sulphate. Chondroitin ABC lyase digestion produced a core protein of Mr 45,000. The core protein, after treatment with HF, had Mr 37,000. Amino acid sequences of the N-terminus and a CNBr-cleavage peptide showed similarity to the sequences of core proteins of small proteoglycans of bovine and human origin, but the N-terminal glycosaminoglycan-attachment site (Ser-Gly-Ile-Ile) differed from the consensus sequence (Ser-Gly-Xaa-Gly) [Bourdon, Krusius, Campbell, Schwartz & Ruoslahti (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 3194-3198]. A polyclonal antibody against the rat cervical DSPG reacted with small proteoglycans from cervices of human, mouse, dog, cow and sheep. DSPG is the major proteoglycan species present in the cervix. The amount of DSPG per cervix increases 4-fold during pregnancy, then falls precipitously within 1 day post partum. A role in cervical dilatation is postulated for this proteoglycan.

Purification and characterization of [formula omitted] lectin from Falcata japonica

An N- acetyl- d- galactosamine-binding lectin from Falcata japonica seeds was purified by affinity column chromatography of N- acetyl- d- galactosamine coupled to epoxy-activated Sepharose 6B. A 1000-fold purification of lectin was obtained from the crude extracts. The purified lectin agglutinated blood group A red cells, but neither blood group B nor O red cells. Polyacrylamide gel electrophoresis of the lectin showed one diffuse band. Molecular weights of 125 000 and 117 000 were estimated by gel filtration and ultracentrifugal analysis, respectively. SDS-polyacrylamide gel electrophoresis of the lectin also showed a single band which has a molecular weight of 34 000. Therefore, the lectin molecule was estimated to be a tetramer composed of four identical non-covalently bound subunits. F. japonica lectin was a glycoprotein containing 5% total carbohydrate, and the amino acid composition was characterized by a high content of aspartic acid, serine and glycine, a low content of methionine and the absence of cysteine.