Sephadex G-200 Gel Chromatography Research Articles

Screening of sweet potatoes varieties, physicochemical and biological activity studies of glycoproteins of selected varieties

In order to meet the nutritional and health needs of different consumers, the main nutrients of eight new sweet potatoes (SPs) varieties were to characterize by principal component analysis. The watermelon red (WR) variety is proving to be the preferred SPs variety because of its high nutritional value and unique sensory features. Three homogeneous fractions SPFG-1, SPFG -2 and SPFG-3 with yield of 53.02% ± 3.20%, 10.50% ± 0.61% and 5.20% ± 0.35% were obtained from the WR by multifrequency ultrasonic extraction (MUE), isolated and purified with DEAE Sepharose CL-6B and Sephadex G-100 gel chromatography. Physiochemical and structural characteristics of three fractions were studied with chemical components analysis, HPLC, HPGPC, and β-elimination, UV, FT-IR and CD spectrum analysis. SPFG-1, SPFG-2 and SPFG-3 were all conjugates with O-glycosylation with the molecular weight of 30.42 ± 2.12, 391.15 ± 25.12 and 6.85 ± 0.78 kDa, including seven monosaccharides and 17 amino acids with quite different mole percentages, that they were predominantly α-helix, β-folding and irregularly curled with a relatively small β-turning content. Meanwhile, the three conjugates exhibited excellent antioxidant and hypoglycemic activities by radical scavenging, α-glycosidase and α-amylase inhibition assays. These findings are helpful to promote the breeding, cultivation and promotion of new SPs varieties with higher nutritional value, as well as the development and application of glycoproteins.

Poly(Styrene-Co-Maleic Acid)-Conjugated 6-Aminofluorescein and Rhodamine Micelle as Macromolecular Fluorescent Probes for Micro-Tumors Detection and Imaging.

Styrene-co-maleic acid (SMA) copolymer was evaluated as a polymer platform to conjugate with two fluorescent dyes, i.e., 6-aminofluorescein (AF) and Rhodamine (Rho); which spontaneously self-assembles in an aqueous medium and forms a micelle through a non-covalent interaction. These SMA-dye conjugates showed the nanosized micelle formation through dynamic light scattering (DLS) with discrete distributions having mean particle sizes of 135.3 nm, and 190.9 nm for SMA-AF, and SMA-Rho, respectively. The apparent molecular weight of the micelle was evaluated using Sephadex G-100 gel chromatography and it was found that the 49.3 kDa, and 28.7 kDa for SMA-AF, and SMA-Rho, respectively. Moreover, the biodistribution study showed the selective accumulation of the SMA-dye conjugates in the tumor of mice. Taken together, the SMA-dye conjugated micelles appear in high concentrations in the tumor by utilizing the enhanced permeability and retention (EPR) effect of the tumor-targeted delivery. These results indicate that SMA-dye conjugates have the advanced potential as macromolecular fluorescent probes for microtumor imaging by means of a photodynamic diagnosis.

Interactions of dextransucrase purified from Streptococcus mutans 890 with plant polyphenols

Plant polyphenols have been extensively studied for their chemopreventive properties for human health. Dextransucrase plays an essential role in synthesizing exopolysaccharides from its exclusive substrate sucrose in Streptococcus mutans. In the present study, the effect of polyphenols gallic acid and tannic acid was investigated on the dextransucrase activity. The enzyme was purified by ethanol precipitation followed by column chromatography by Sephadex G-200 gel chromatography, followed by PEG-400 treatment. The purified enzyme exhibited 52 fold enrichment with 17.5% yield and specific activity of 3.54 Units/mg protein. On SDS-PAGE enzyme protein gave a single band with a molecular weight of 160 kDa. Dextransucrase activity was inhibited 80–90% by 0.04 mM tannic acid (TA) or 0.4 mM gallic acid (GA) suggesting that tannic acid has 10- fold more inhibitory potential than gallic acid on the activity of dextransucrase. CD/ORD studies revealed modifications in the tertiary structure of enzyme protein in presence of tannic acid and gallic acid, which were further confirmed by fluorescence spectra of the protein in presence of tannic acid. These results suggest that inhibition of dextransucrase activity in S. mutans by polyphenols may have potential applications in the prevention and control of dental caries.

Structural characterization of a homopolysaccharide with hypoglycemic activity from the roots of Pueraria lobata.

A water-soluble neutral homopolysaccharide (PLP-1) was obtained from the roots of Pueraria lobata by DEAE cellulose and Sephadex G-200 gel chromatography purification. The average molecular weight of PLP-1 was 16.2 kDa. Monosaccharide composition analysis showed that PLP-1 was composed of glucose as a glucan. The structure of PLP-1 was characterized on the basis of extensive physical and chemical analysis, which indicated that the backbone of PLP-1 was mainly composed of →3)-α-d-Glcp(1→ and →4)-β-d-Glcp(1→ with a molar ratio of 7.0 : 1.0. Moreover, the hypoglycemic activity of PLP-1 was investigated by palmitic acid and high glucose induced insulin resistant HepG2 cells. The results elucidated that PLP-1 could decrease the glucose concentration by up-regulating the expression of PI3K and AKT, and down-regulating the expression of FoxO1, PCK2, and G6Pase in insulin resistant cells. Therefore, PLP-1 could serve as a dietary supplement to ameliorate insulin resistance for diabetic patients.

Purification and Characterization of Produced Cellulase Enzyme by Irradiated Achromobacter spanius

Achromobacter spanius was endophytic bacteria cellulase producing . It was irradiated by gamma rays at doses from 0.5 – 5 kGy. The irradiated Achromobacter spanius increase extracellular cellulase enzyme activity over the non-irradiated strain. Irradiated strain at dose 3.5 kGy was identified as higher cellulase enzyme activity than those of other doses. Purification and characterization of cellulase produced by irradiated Achromobacter spanius was done. The cellulase enzyme was purified by applying sephadex G-100 gel chromatography technique. The highest activity of cellulase was obtained at enzyme volume and incubation period 0.2 ml and 30 minutes respectively. The optimum pH value was 7 and the optimum activity with temperature was 35 oC. The enzyme showed the highest activity when carboxmethyl cellulose (CMC) used as substrate on reaction mixture. According to thermal stability, the purified cellulase has high activity after 5 minute when purified enzyme was incubated at 60 OC. The purified cellulase, with a molecular weight (M.W.) of 32.5 kDa,

An alkaline pectate lyase D from Dickeya dadantii DCE-01: clone, expression, characterization, and potential application in ramie bio-degumming

Pectinase plays a crucial role in ramie bio-degumming. A pectate lyase gene ( pel4J4) from the high-efficiency degumming bacteria Dickeya dadantii DCE-01 of bast fibers was cloned and connected to pET28a, and then the recombinant plasmid was successfully transformed into Escherichia coli BL21(DE3). The pectate lyase (Pel4J4) induced was purified by ultrafiltration and Sephadex G-100 gel chromatography. The enzymatic properties of Pel4J4 were studied in detail. pel4J4 (GenBank accession number: KC900167) had a sequence length of 1179 bp, encoding 392 amino acids. The extracellular pectate lyase activity of pET28a- pel-BL was up to 204.4 IU/mL. The optimal temperature and pH of the purified Pel4J4 were 55℃ and 8.5, respectively. The stable temperature and pH of Pel4J4 activity were 45℃ and 8.5–10.0, respectively. The catalytic activity is Ca2+ dependent and promoted by 1 mmol/L Zn2+, Fe3+, Ca2+, and NH4+, but seriously inhibited by Cu2+ and Pb2+. The optimal substrate is citrus pectin with more than 85% esterification. The heat-resistant alkaline Pel4J4 could strongly degrade natural ramie pectin, indicating a promising application prospect in ramie bio-degumming.

Effects of intrinsic metal ions of lentinan with different molecular weights from Lentinus edodes on the antioxidant capacity and activity against proliferation of cancer cells

In this study, effects of intrinsic metal ions in lentinan on its bioactivities were evaluated. Lentinan extracted from Lentinus edodes was separated to four fractions with different molecular weights with Sephadex G-200 gel chromatography, and intrinsic metal ions were removed by EDTA. The ferrous ion chelating capacity of ELWs was measured to estimate EDTA residue after extensive dialysis. Antioxidant and antitumor activities of the isolated lentinans (LWs and ELWs) were investigated in vitro and compared, respectively. The results indicated that all of the isolated lentinan contained a large amount of intrinsic metal ions and the fraction with the lowest Mw had highest metal content. After removing intrinsic metal ions, the polysaccharides showed lower ABTS and DPPH radicals scavenging capacity and the reduced inhibition of the proliferation of BXPC-3 and Hela cells. Our results indicated that the metal ions in lentinan had positive effects on its bioactivities.

Extraction Optimization, Purification and Physicochemical Properties of Polysaccharides from Gynura medica.

Extraction of polysaccharides from Gynura medica (GMPs) was optimized by response surface methodology (RSM). A central composition design including three parameters, namely extraction temperature (X1), ratio of water to raw material (X2) and extraction time (X3), was used. The best conditions were extraction temperature of 91.7 °C, extraction time of 4.06 h and ratio of water to raw material of 29.1 mL/g. Under the optimized conditions, the yield of GMPs was 5.56%, which was similar to the predicted polysaccharides yield of 5.66%. A fraction named GMP-1 was obtained after isolation and purification by DEAE-52 and Sephadex G-100 gel chromatography, respectively. GMP-1, with a molecular weight of 401 kDa, mainly consisted of galacturonic acid (GalA), xylose (Xyl), glucose (Glu). Infrared spectroscopy was used to characterize the major functional groups of GMP-1 and the results indicated that it was an acidic polysaccharide. The antioxidant and α-glucosidase inhibitory activities of GMPs and GMP-1 were determined in vitro. The results indicated that GMPs and GMP-1 show potential for use in functional foods or medicines.

Purification and Characterization of a Protease Produced by a Planomicrobium sp. L-2 from Gut of Octopus vulgaris

Protease widely exists in the digestive tract of animals and humans, playing a very important role in protein digestion and absorption. In this study, a high protease-producing strain Planomicrobium sp. L-2 was isolated and identified from the digestive tract of Octopus variabilis. The strain was identified by physiological and biochemical experiments and 16S rDNA sequences analysis. A protease was obtained from the strain Planomicrobium sp. L-2 through ammonium sulfate precipitation, dialysis and enrichment, DEAE-Sephadex A50 anion-exchange chromatography, and Sephadex G-100 gel chromatography. The molecular weight and properties of the protease were characterized, including optimum temperature and pH, thermal stability, protease inhibitions and metal ions. According to our results, the protease from Planomicrobium sp. L-2 strain designated as F1-1 was obtained by three-step separation and purification from crude enzyme. The molecular weight of the protease was 61.4 kDa and its optimum temperature was 40°C. The protease F1-1 showed a broad pH profile for casein hydrolysis between 5.0~11.0. No residual activity was observed after incubation for 40 min at 60°C and 60 min at 50°C. F1-1 protease was inhibited by Mn2+, Hg2+, Pb2+, Zn2+, and Cu2+ ions, as well as PMSF, indicating that the protease F1-1 was a serine protease. Additionally, research basis provided by this study could be considered for industrial application of octopus intestinal proteases.

Biopulping of sugarcane bagasse and decolorization of kraft liquor by the laccase produced by Klebsiella aerogenes NCIM 2098

Aims: Laccase, a copper-containing enzyme, oxidizes variety of aromatic compounds. Since laccase is essential for lignin degradation, it can be used for lignin removal in the pulp and paper industry (biopulping). Laccase is also employed as a dechlorinating agent (biobleaching), along with the removal of phenolic and other aromatic pollutants. In the present investigation it was aimed to employ the laccase produced by the bacterium Klebsiella aerogenes along with the bacterium itself in biopulping of sugarcane bagasse and biobleaching of kraft liquor effluent. Methodology and results: A laccase was isolated from the bacterium K. aerogenes, purified to homogeneity and characterized. The enzyme was purified by conventional techniques following salt precipitation, ion exchange chromatography, and affinity chromatography on Con A sepharose. The purified laccase was found to be monomeric glycoprotein with a Mr of 64 kDa when measured by Sephadex G-200 gel chromatography and SDS-PAGE. The Vmax and Km of laccase towards the substrate guaiacol was determined. The optimum pH of the laccase was found to be 5.0. biopulping and biobleaching activities were determined by TAPPI standard methods. Treatment of sugarcane baggase by K. aerogenes also significantly reduced lignin content of the bagasse. Conclusion, significance and impact of study: The bacterium K. aerogenes and a laccase produced by it were used separately for biopulping of sugarcane bagasse and biobleaching of kraft liquor effluent. Treatment with both brought significant reduction in lignin content and kappa number of the pulp. The handsheets prepared from the treated pulp showed improved brightness without affecting the strength properties of paper. The bacterium and the laccase efficiently decolorized the kraft liquor proving to have biobleaching potential.

Functional expression of FIP-fve, a fungal immunomodulatory protein from the edible mushroom Flammulina velutipes in Pichia pastoris GS115

FIP-fve is a bioactive protein isolated from the mushroom Flammulina velutipes, which belongs to the fungal immunomodulatory protein (FIP) family and demonstrates several kinds of biological activities including anti-allergy, anti-tumor and immunomodulation. In the current study, the FIP-fve gene was cloned and expressed in the yeast Pichia pastoris GS115, and its correctness was confirmed by SDS-PAGE and Western blot. Optimal expression of rFIP-fve was observed when the P. pastoris cells were cultured in 1% methanol for 96h, which resulted in a yield of 258.2mgl−1. The rFIP-fve protein was subsequently purified via ammonium sulfate precipitation and Sephadex G-100 gel chromatography. In vitro bioactivity examination showed that rFIP-fve could agglutinate human red blood cells and stimulate the cell viability of murine splenocytes. The immunomodulatory capacity and anti-tumor activity of rFIP-fve were demonstrated by enhanced interleukin-2 secretion and interferon-γ release from the murine lymphocytes, similar to the biological FIP-fve. In conclusion, the FIP-fve gene was functionally and effectively expressed in P. pastoris, and rFIP-fve displayed biological activities similar to those of native FIP-fve. These results indicated the potential use of rFIP-fve from P. pastoris as an effective and feasible source for therapeutic studies and medical applications.

Purification and characterization of cell-envelopeproteinase from Lactobacillus casei DI-1

Using a Ca 2+ -free method, the cell-envelope proteinase (CEP) of Lactobacillus casei DI-1 isolated from duck small intestine was released from cells and purified by ammonium sulfate precipitation, and by diethylaminoethyl (DEAE)-Sephadex A-25 and Sephadex G-100 gel chromatography. The purified CEP had a monomer structure with a molecular mass of about 35 kDa. Optimal activity occurred at pH 7.0 and 37°C. The purified CEP was a metallopeptidase, which was activated by Co 2+ , Ba 2+ , Mg 2+ and Fe 3+ , and inhibited by Ca 2+ , Zn 2+ , K + , Ni 2+ , Mn 2+ , and ethylenediaminetetraacetic acid (EDTA). It was a serine proteinase which was inhibited by phenylmethylsulfonyl fluoride (PMSF). Its kinetic constant (Km) is 0.29 mM and the first 10 amino acids of the CEP’s N-terminal sequences were Asp-Asn-Asp-Phe-Glu-Ile-Phe-Glu-Ser-Ser. The hydrolysates of α-, β- and κ-casein produced by CEP showed different angiotensin-I-converting enzyme (ACE) inhibitory activity; the hydrolysates of β-casein displayed the greatest ACE inhibitory activity. Key words : Cell-envelope proteinase, purification, characterization.

Purification and characterization of the cold-active alkaline protease from marine cold-adaptive Penicillium chrysogenum FS010

An extracellular cold-active alkaline serine protease from Penicillium chrysogenum FS010 has been purified. The purification procedure involved: ammonium sulfate precipitation, DEAE ion-exchange chromatography and sephadex G-100 gel chromatography. SDS-PAGE of the purified enzyme indicated a molecular weight of 41,000 +/- 1,000 Da. The protease is stable in a pH range of 7.0-9.0 and has a maximum activity at pH 9.0. Compared with other industrial proteases, the enzyme shows a high hydrolytic activities at lower temperatures and a high sensitivity at a temperature over 50 degrees C. The isoelectric point of the enzyme is approximate to 6.0. Enzymatic activity is enhanced by the addition of divalent cations such as Mg(2+) and Ca(2+) and inhibited by addition of Cu(2+)and Co(2+). PMSF and DFP are its specific inhibitors. The application of the cold-active alkaline protease is extremely extensive, and widely used in detergents, feed, food, leather and many other industries.

Prostasome-like vesicles stimulate acrosome reaction of pig spermatozoa

BackgroundThe presence of small membranous particles characterizes the male genital fluids of different mammalian species. The influence of semen vesicles, denominated prostasomes, on sperm functional properties has been well documented in humans, but their biological activity is scarcely known in other species. The present work investigated prostasome-like vesicles in pig semen for their ability to interact with spermatozoa and to affect acrosome reaction.MethodsProstasome-like vesicles have been isolated from pig seminal plasma by high-speed centrifugation and Sephadex G-200 gel chromatography. Morphology of purified vesicles has been checked by scanning electron microscopy while their protein pattern has been investigated by SDS-PAGE. Then prostasome- like vesicles have been incubated with pig spermatozoa and their ability to interact with sperm has been tested by the aminopeptidase assay. In addition, the efficiency of vesicles to influence the acrosome reaction has been investigated by assessing the sperm acrosomal status by the PI/FITC-PNA (propidium iodide/fluorescein isothiocyanate-labeled peanut agglutinin) stainings.ResultsPurified vesicles revealed a complex protein pattern with the occurrence of bands in the high, medium and low molecular weight range. However, the two major bands were observed at ~90 kDa and ~60 kDa. A vesicle-mediated transfer of aminopeptidase to sperm cells has been also detected. Furthermore, a significant increase of acrosome reaction extent has been revealed in spermatozoa incubated with prostasome-like vesicles in comparison to control sperm.ConclusionThis is the first report demonstrating that pig prostasome-like vesicles are able, in vitro, to interact with spermatozoa and to stimulate the acrosome reaction. These findings lead to hypothesize a transfer of molecules from vesicles to sperm membrane, thus sensitizing male gametes to undergo the acrosome reaction

Chemical characteristics and immuno-modulating activities of exo-biopolymers produced by Grifola frondosa during submerged fermentation process

The immuno-modulating activities and chemical characteristics of exo-biopolymer (EX-GF) produced by a submerged mycelial culture of Grifola frondosa were studied. The EX-GF was fractionated into EX-GF-Fr.I, II, and III by Sephadex G-100 gel chromatography. Anti-complementary activity of EX-GF-Fr.III was highest (71.1%) among them, and its activation system occurred through both classical and alternative pathways, where the classical pathway found to be major one. Lysosomal enzyme activity and nitric oxide production ability of macrophage were also found to be mediated by EX-GF-Fr.III. The molecular weight of the EX-GF-Fr.I, II, and III was estimated to be about 163, 40, and 2.8 kDa, respectively. Total sugar and protein contents of the three fractions were 80.3, 61.9 and 89.3%, and 17.3, 35.2, and 10.7%, respectively. The sugar and amino acid compositions of the EX-GF-Fr.I, II, and III were also analyzed in detail.

Study of chromium-containing proteins in subcellular fractions of rat liver by enriched stable isotopic tracer technique and gel filtration chromatography.

Ten male Wistar rats were intravenously injected with a single approximately physiological dose of enriched stable isotopic Cr-50 tracer solution (200 ng (50)Cr(3+)/100 g body wt). The fundamental distribution patterns of the chromium-containing proteins in the nucleic, mitochondrial, lysosomal, microsomal, and cytosolic subcellular fractions of the rat liver were investigated by means of Sephadex G-100 gel chromatography combined with neutron activation analysis via (50)Cr (n, gamma) (51)Cr reaction. In total, nine kinds of Cr-containing proteins were found in the five subcellular fractions, whose relative molecular masses were 96.6+/-6.2, 68.2+/-1.4, 57.9+/-4.7, 36.6+/-1.2, 24.2+/-1.8, 14.0+/-1.5, 8.8+/-0.6, 6.9+/-0.4, and 4.2+/-0.4 kDa. Approximately 64.5% of Cr proteins accumulated in the cytosolic fraction. The second enriched part was the nucleic fraction; about 12.2% Cr proteins were stored in this section. The 4.2-kDa molecular mass might contain the so-called low molecular weight chromium-containing substance; however, in this research, it was only observed in the mitochondria, lysosome, and microsome. In the mitochondrial fraction, most of the Cr proteins were present as relatively low molecular weight substances: about 56% of chromium-containing proteins had molecular masses < or =6.9 kDa. Nevertheless, more than 69% of Cr-containing proteins were observed with molecular masses > or =57.9 kDa in the liver cytosolic fraction.

Purification and characterization of bifunctional alginate lyase from Alteromonas sp. strain no. 272 and its action on saturated oligomeric substrates.

A marine bacterium (strain No. 272) isolated from sea mud in Omura Bay produced an alginate lyase and was classified as an Alteromonas species. The enzyme was purified from the culture medium of the bacterium by DEAE-Cellulofine, Sephadex G-100 gel chromatography to an electrophoretically homogeneous state in the presence and absence of SDS. The molecular mass of the enzyme was 23 and 33.9 kDa on Sephadex G-100 column chromatography and SDS-polyacrylamide gel electrophoresis, respectively, with an isoelectric point of 3.8. The predominant secondary structure of the enzyme was found to be most likely beta-structure by circular dichroism. The enzyme was most active at pH 7.5-8.0 and stable around pH 5-11. The enzyme was more labile in Tris-HCI buffer (pH 7.0) to heat treatment, than in phosphate buffer (pH 7.0). No of metal ions significantly affected the enzyme activity. The enzyme acted on sodium alginate in an endo-type manner and on two components of alginate, poly-alpha1,4-L-guluronate and poly-beta1,4-D-mannuronate, as judged by routine ultraviolet assay (235 nm) and circular dichroic spectral changes of the substrates. However, the coexisting poly-alpha1,4-L-guluronate and poly-beta1,4-D-mannuronate apparently interacted with the enzyme in a competitive manner. Although the enzyme depolymerized alginate in an endo-type, it did not act on trimeric guluronate and mannuronate, but on the tetramers or more. The kinetic analyses showed that kcat/Km for each oligomer was larger for the guluronate oligomers than for the mannuronate ones, and that the subsite structure of the enzyme most likely consisted of six binding sites from the intrinsic reaction rate constant (kint) and intrinsic substrate binding constant (Kint).

Acid phosphatases excreted by Humicola lutea 120-5 in casein-containing medium

The fungus Humicola lutea 120-5 cultivated in casein-containing media, in the presence or absence of inorganic phosphate (Pi), excretes three different molecular forms of acid phosphatase (with Mr values of approximately 140, 70 and 35 kDa). The enzyme forms were isolated and purified 30–100-fold by a procedure involving two steps of ion-exchange chromatography and Sephadex G-200 gel chromatography. It was found that the fungus excretes only one of the phosphatases with the highest Mr (140 kDa) during growth on medium with inorganic nitrogen source (NaNO3). This form (designed AcPh I) was assumed to be a constitutive, since it showed resistance to high Pi-concentrations (10 mM) and its biosynthesis was not affected by the type of nitrogen source (casein or NaNO3). The other two forms (AcPh II-70 and AcPh III-35 kDa) were competitively inhibited by Pi (K i = 0.5 and 0.2 mM, respectively) and were induced by casein. The K m values of AcPh I and AcPh II were estimated as 1.3 mM, while AcPh III showed a higher affinity for p-nitrophenylphosphate (pNPP) with K m of 0.5 mM. The AcPh I–III fractions demonstrated a pH optimum in the range of 4.5–4.8 and an optimal temperature of 55 °C using pNPP as a substrate.

Identification of an alkaline sphingomyelinase activity in human bile

The hydrolysis of sphingomyelin has been found to generate important signals regulating cell proliferation, differentiation and apoptosis. However, the enzymes responsible for digestion of dietary sphingomyelin have not been well documented. This study demonstrates the occurrence of a sphingomyelinase (SMase) in both human hepatic bile and gallbladder bile. The enzyme was equally found in both bacteria negative and positive bile samples and in samples obtained from patients with or without gallbladder diseases. A bacteria-free gallbladder bile was used for characterization. It was found that bile SMase hydrolyzed sphingomyelin to phosphorylcholine and ceramide with negligible activity against either phosphatidylcholine or p-nitrophenyl phosphate. The enzyme preferred an alkaline condition and the optimal pH was 9. The activity of this alkaline SMase was bile salt dependent and was fully activated by 4–6 mM bile salts. Triton X-100, the non-ionic detergent did not activate bile SMase. Ca 2+ and Mg 2+ ions had no significant effect at optimal bile salt concentration. The molecular mass of this enzyme was about 85 kDa as measured by Sephadex G200 gel chromatography. In conclusion, we demonstrated a SMase in bile which differs markedly from the known acid and neutral SMase. Its potential important roles in sphingomyelin digestion and gallbladder diseases require further investigation.

Purification and Characterization of a Glycine-rich Protein from the Aleurone Layer of Soybean Seeds

Glycine-rich protein (GRP) was extracted with hot water from cell walls of the aleurone layer of soybean seeds and solubilized by pectinase treatment. GRP was purified by Sephadex G-100 gel chromatography, anion exchange HPLC, and reverse-phase HPLC. Two GRP fractions that had almost the same amino acid composition were found by gel chromatography. The high-molecular-mass G RP seems to be an associated form of the low-molecular-mass GRP (30-kDa). Thirty-kDa GRP was separated into a major GRP-I and a minor GRP-II by anion exchange HPLC. The major amino acids of GRP-I purified by reverse-phase HPLC were glycine (68%) and serine (12%). GRP-I contained a small proportion of sugar, approximately 9% (w/w), and mannose, arabinose, glucose, xylose, and galactose were included in the sugar moiety. The N-terminal amino acid sequence of GRP-I was a novel polyglycine structure including at least 20 glycine-repeated sequence. The GRP-I might be a novel type of extracellular matrix protein specific to the aleurone layer.