Abstract  Maintenance of physiological levels of intracellular and extracellular calcium is essential for life. Increased intracellular calcium levels are involved in cell death (apoptosis and necrosis) and are associated with positive responses in the Comet assay in vitro. In addition, high calcium and vitamin D intakes were reported to induce apoptosis in adipose tissue in obese mice and to increase DNA-migration in the Comet assay. To investigate increased serum concentration of calcium as a potential confounding factor in the regulatory Comet assay in vivo, we induced mild hypercalcemia in male Wistar rats by 3-day continuous intravenous infusion of calcium gluconate and performed the Comet assay in the liver in line with regulatory guidelines. The results of the study showed that mild increases in serum calcium concentration (up to 1.4 times above the concurrent control) and increased urinary calcium concentration (up to 27.8 times above the concurrent control) results in clinical signs like mild tremor, faster respiration rate and decreased activity in a few animals. However, under the conditions of the study, no increase in the %Tail DNA in the Comet assay and no indication of liver damage as determined by histopathological means were observed. Thus, mild increases in plasma calcium did not lead to positive results in a genotoxicity assessment by the Comet assay in the rat liver. This result is important as it confirms the reliability of this assay for regulatory evaluation of safety.

Abstract  BACKGROUND: Peripheral blood progenitor cell (PBPC) collection has become the main source of hematopoietic cells for high-dose chemotherapy with stem cell rescue and, in some protocols, for allogeneic hematopoietic transplantation. This procedure is complicated in the smallest children because of difficulties related to their weight, and there is little published experience. We have conducted a prospective study to analyze the incidence of adverse events during PBPC collection in the smallest children (< or = 10 kg).

METHODS: From January 2000 to November 2005, 257 leukapheresis were performed in our unit, and 13 of them (5%) in 12 children weighing up to 10 kg (median 9 kg, range 5.8-10.9 kg).

RESULTS: Most cases had hypovolemic signs during the procedure (usually tachycardia); six cases had hypotension, five of them with pallor and diaphoresis, and, of those, two also had nausea. In all these cases infusion of saline or plasma volume expanders resolved the clinical findings. In two cases the nausea related to hypocalcemia was resolved after calcium gluconate infusion. Changes in platelet counts were also remarkable, with a median platelet loss of 52%.

DISCUSSION: Leukapheresis with continuous-flow cell separators has frequent complications related to volume shift in the smallest children. These adverse events are mild and easily resolved with standard measures for hypovolemia, as plasma expander or normal saline infusions. However, we recommend that the procedure should only be performed by teams with extensive experience in the field.

Abstract  There have been many reports exploring the engineering of the cofactor specificity of aldo-keto reductases (AKRs), as this class of proteins is ubiquitous and exhibits many useful activities. A common approach is the mutagenesis of amino acids involved in interactions with the 2'-phosphate group of NADP(H) in the cofactor binding pocket. We recently performed a 'loop-grafting' approach to engineer the substrate specificity of the thermostable alcohol dehydrogenase D (AdhD) from Pyrococcus furiosus and we found that a loop insertion after residue 211, which is on the back side of the cofactor binding pocket, could also alter cofactor specificity. Here, we further explore this approach by introducing single point mutations and single amino acid insertions at the loop insertion site. Six different mutants of AdhD were created by either converting glycine 211 to cysteine or serine or by inserting alanine, serine, glycine or cysteine between the 211 and 212 residues. Several mutants gained activity with NADP+ above the wild-type enzyme. And remarkably, it was found that all of the mutants investigated resulted in some degree of reversal of cofactor specificity in the oxidative direction. These changes were generally a result of changes in conformations of the ternary enzyme/cofactor/substrate complexes as opposed to changes in affinities or binding energies of the cofactors. This study highlights the role that amino acids which are distal to the cofactor binding pocket but are involved in substrate interactions can influence cofactor specificity in AdhD, and this strategy should translate to other AKR family members.

Abstract  Total synthesis of naturally occurring Oxylipin has been achieved from open chain gluco-configured building block which is readily assembled from inexpensive and commercially available D-(+)-gluconolactone. Grignard reaction and Wittig olefination reactions are key steps for the requisite CC bond formation.

Abstract  A novel polysaccharide named Fenugreek Water-Soluble Polysaccharide (FWSP), consisting of a gluconic acid polymer, was isolated from fenugreek seeds. It was structurally characterized by Fourier transformed infrared (FT-IR), X-ray diffraction (XRD), High performance liquid chromatograpy (HPLC), and Nuclear magnetic resonance (NMR) spectroscopies. FT-IR and NMR spectra showed the characteristic bands of polysaccharides. According to XRD spectrum, FWSP is a semi-crystalline polymer. Functional properties of FWSP were investigated based on Water Holding Capacity (WHC), Oil Holding Capacity (OHC), emulsification activity, and foaming ability. FWSP was capable of emulsifying several food-grade oils and hydrophobic compounds, especially corn oil and hexane. The effects of FWSP on oxidative processes in beef sausages during refrigerated (4°C) storage was investigated. The results showed significant inhibition (p<0.05) of lipid and myoglobin oxidation and provided evidence that FWSP is a potent and useful antioxidant for maintaining storage stability of beef sausages, and could replace vitamin C currently used as antioxidant in industry process.

Abstract  NAD(P)-dependent glucose-1-dehydrogenase (GDH) has been used for glucose determination and NAD(P)H production in bioreactors. Thermostable glucose dehydrogenase exhibits potential advantage for its application in biological processes. The function of the putative GDH gene (ST1704, 360-encoding amino acids) annotated from the total genome analysis of a thermoacidophilic archeaon Sulfolobus tokodaii strain 7 was investigated to develop more effective application of GDH. The gene encoding S. tokodaii GDH was cloned and the activity was expressed in Escherichia coli, which did not originally possess GDH. This shows that the gene (ST1704) codes the sequence of GDH. The enzyme was effectively purified from the recombinant E. coli with three steps containing a heat treatment and two successive chromatographies. The native enzyme (molecular mass: 160 kDa) is composed of a tetrameric structure with a type of subunit (41 kDa). The enzyme utilized both NAD and NADP as the coenzyme. The maximum activity for glucose oxidation in the presence of NAD was observed around pH 9 and 75 degreesC in the presence of 20 mM Mg2+. The enzyme showed broad substrate specificity: several monosaccarides such as 6-deoxy-D-glucose, 2-amino-2-deoxy-D-glucose and D-Xylose were oxidized as well as D-glucose as the electron donor. D-Mannose, D-ribose and glucose-6-phosphate were inert as the donor. The enzyme showed high thermostability: remarkable loss of activity was not observed up to 80 degreesC by incubation for 15 min at pH 8.0. In addition, the enzyme was stable in a wide pH range of 5.0-10.5 by incubation at 37 degreesC. From the steady-state kinetic analysis, the enzyme reaction of D-glucose oxidation proceeds via a sequential ordered Bi-Bi mechanism: NAD and D-glucose bind to the enzyme in this order and then D-glucono-1,5-lactone and NADH are released from the enzyme in this order. The amino acid sequence alignment showed that S. tokodaii GDH exhibited high homology with the Sulfolobus solfataricus hypothetical glucose dehydrogenase and a Thermoplasma acidophilum one. (C) 2003 Elsevier B.V. All rights reserved.

Abstract  Background: Primary hypoparathyroidism (PH) is an endocrine disorder characterized by decreased production and/or release of parathyroid hormone (PTH). Dogs and cats are rarely affected, and typical clinical signs include an abrupt onset of neurological and neuromuscular signs. The diagnosis is based on the history, clinical signs, and laboratory findings of hypocalcaemia, as well as the exclusion of other causes of tetany. Treatment involves stabilization of serum calcium with specific therapy. This study aimed to report three cases of PH: two canine cases and the first feline case in Brazil.

Cases: 1) A 8-year-old male Yorkshire terrier was brought to the clinic with a history of tetanic crisis. The owner reported that the animal had been previously diagnosed with epilepsy and since treated with phenobarbital. The physical examination revealed hyperthermia, tachypnea, tachycardia, salivation, and ataxia with hyperextension of the anterior and posterior limbs. Emergency treatment included intravenous (IV) administration of calcium gluconate, and the animal showed clinical improvement within an hour. Overall, the complete blood count was within the normal range, but the calcium and PTH levels were below the normal ranges. Therefore, PH was confirmed. Calcium carbonate and vitamin D3 supplementation were prescribed, and the treatment with phenobarbital was suspended. During the following year, the dog suffered three episodes of hypocalcaemia, even with appropriate administration of medication by the owner. In the last crisis, the animal died, probably because of acute renal failure (ARF). 2) A 7-year-old male Pinscher was presented for veterinary care with a history of 15 days of tetanic and seizure crises. The physical examination revealed hyperthermia, seizure activity, and hyperextension of the anterior and posterior limbs. Levels of total calcium and PTH were below the normal ranges. The animal showed clinical improvement with IV administration of calcium gluconate. Therefore, PH was diagnosed from the clinical signs, response to emergency treatment, and values of calcium and PTH. Calcium carbonate and vitamin D3 supplementation were prescribed. The owner had trouble purchasing calcitriol, and the animal died before the follow-up appointment. 3) A 14-year-old female mixed-breed cat was brought to the clinic with a history of anorexia and vomiting. From the results of the complete blood count, serum biochemistry, and electrocardiogram, the cat was diagnosed initially with hypertrophic cardiomyopathy with hepatic lipidosis due to prolonged anorexia. However, the serum ionized calcium and PTH levels were below normal ranges. Thus, on the basis of the clinical symptoms and serum calcium and PTH levels, the animal was diagnosed with PH. Treatment consisted of ongoing supplementation with vitamin D3 and calcium carbonate, and the existing treatment for heart disease was continued. The treatment did not result in any clinical improvement, and the animal was euthanized.

Discussion: The two dogs presented with the classic symptoms reported in the literature. However, the cat with the same pathology had different clinical signs. In the three cases, the diagnosis was confirmed according to the procedure described in the literature, ie, clinical symptoms, serum calcium and PTH levels below normal ranges, and response to treatment. The stabilization of the serum calcium concentration with calcium and vitamin D3 supplementation corroborates the literature. None of the study patients survived: the first dog probably died because of ARF due to excessive crises; the second dog died because of the advanced stage of the disease and the difficulty in purchasing the drugs prescribed; the cat was euthanized because it did not show any response to treatment, perhaps because it had more than one disease concurrently.

Abstract  Biosynthesis of polyhydroxyalkanoates (PHAs) consisting of 3-hydroxyalkanoates (3HAs) of 4 to 10 carbon atoms was examined in metabolically engineered Escherichia coli strains. When the fadA and/or fadB mutant E. coli strains harboring the plasmid containing the Pseudomonas sp. 61-3 phaC2 gene and the Ralstonia eutropha phaAB genes were cultured in Luria-Bertani (1,13) medium supplemented with 2 g/L of sodium decanoate, all the recombinant E. coli strains synthesized PHAs consisting of C4, C6, C8, and C10 monomer units. The monomer composition of PHA was dependent on the E. coli strain used. When the fadA mutant E. coli was employed, PHA containing up to 63 mol% of 3-hydroyhexanoate was produced. In fadB and fadAB mutant E. coli strains, 3-hydroxybutyrate (3HB) was efficiently incorporated into PHA up to 86 mol%. Cultivation of recombinant fadA and/or fadB mutant E. colistrains in LB medium containing 10 g/L of sodium gluconate and 2 g/L of sodium decanoate resulted in the production of PHA copolymer containing a very high fraction of 3HB up to 95 mol%. Since the material properties of PHA copolymer consisting of a large fraction of 3HB and a small fraction of medium-chain-length 3HA are similar to those of low-density polyethylene, recombinant E. coli strains constructed in this study should be useful for the production of PHAs suitable for various commercial applications.

Abstract  Lipase-mediated regioselective biotransformations such as hydrolysis and alcoholysis of 3,4,6-tri-O-acetyl-D-glucal, 1 have been studied in organic solvent, tetrahydrofuran (THF) and two different ionic liquids, namely 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim]PF6 and 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim]BF4. The influence of different reaction media on the rates and regioselectivity of enzyme catalysis has been demonstrated. A marked regioselectivity towards the formation of 4,6-di-O-acetyl-D-glucal, 2 was observed in [bmim]PF6 with 84% product formation after 6 h with 98% selectivity in hydrolysis and 48% after 8 h with 98% selectivity in alcoholysis. (C) 2004 Elsevier B.V. All rights reserved.

Abstract  Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g.

Abstract  A 15-month-old child was treated for iron intoxication with a hypertonic sodium phosphate mixture. Clinical deterioration manifested by fever, obtundation, abdominal distention, dehydration, and hypotension followed soon after the administration of this mixture. Such symptoms may occur with either iron overdosage or with phosphate poisoning. At this time, the patient's serum chemistry values included: iron, 49 micrograms/dL; phosphorus, 24.6 mg/dL; and calcium, 4.5 mg/dL. The hypocalcemia, hyperphosphatemia, and dehydration were treated with parenteral gluconate calcium, intravenous fluids, and general supportive measures. Although the child had an uneventful recovery despite severe phosphate poisoning, therapeutic alternatives, such as sodium bicarbonate, should be used as adjuncts in the treatment of acute iron ingestion.

Abstract  Abstract: Alkyl protected glycals can be easily converted into their corresponding alpha,beta-unsaturated enals (Perlin aldehydes) in good to very good yields by reaction with HgSO(4) and aqueous 0.02N H(2)SO(4) in THF or 1,4-dioxane. While the formation of Perlin aldehydes from benzyl-protected glucal and arabinal was accomplished by refluxing the reaction mixture in 1,4-dioxane, the benzyl-protected galactal and methyl-protected glucal, galactal, and arabinal yielded aldehydes from this reaction at room temperature using THF or 1,4-dioxane as SOLVENT*. (C) 2004 Elsevier Ltd. All rights reserved. ds: Agriculture cument Delivery No.: 843XO e field[29]: 1,4-Dioxane

Abstract  A phosphate depletion syndrome developed in a steroid-dependent asthmatic patient. Initially, the clinical picture was confused with steroid-associated myopathy rather than the phosphate depletion syndrome which has similar symptoms. The classic biochemical findings led to the correct diagnosis. Cessation of phosphate-binding antacids and phosphorus repletion rapidly corrected the biochemical findings and led to the patient's clinical improvement. Platelet phosphate metabolism was evaluated; it was found to correlate with the phosphorus-depleted state and clinical recovery with phosphate repletion. Attention is drawn to the clinical entity of phosphate depletion which may mimic steroid-induced side effects, both of which may occur in patients receiving steroids and antacids.

Abstract  OBJECTIVE: To determine whether nicardipine, a dihydropyridine, inhibits the ability of calcium gluconate to reverse magnesium-induced toxicity.

METHODS: The reversal of magnesium-induced neuromuscular blockade of skeletal muscle in the presence of nicardipine was assessed using a nerve stimulator. Nicardipine (12 mg) or an equivalent volume of saline was administered intramuscularly to 19 nonpregnant rabbits in a randomized, blinded manner. Magnesium sulfate, 800 mg, was then infused intravenously in all animals, an amount sufficient to cause toxicity as measured by depression of skeletal muscle twitch and by average serum levels of 10.4 mEq/L. Calcium gluconate (300 mg) was then infused in all animals, and reversal of neuromuscular blockade was measured using the nerve stimulator to compare the saline- and nicardipine-treated groups.

RESULTS: Administration of calcium gluconate was equally effective in reversing magnesium-induced toxicity in both the control and test groups.

CONCLUSION: Nicardipine does not block the ability of calcium gluconate to reverse magnesium-induced neuromuscular blockade.

Abstract  The two electrophilic Vilsmeier-Haack reagents POCl3.DMF 2 or (CF3SO2)2O.DMF 3 mediate the one-step and selective conversion of O-triethylsilyl (O-TES), O-tert-butyldimethylsilyl (O-TBDMS), O-tert-butyldiphenylsilyl (O-TBDPS), and O-triisopropylsilyl (O-TIPS) ethers of D-glucal to the corresponding C(6)-O-formates.

Abstract  Some N-substituted-3-azabicyclo[3.3.0]octen-7-one derivatives have been synthesized in an enantiomerically pure form starting from tri-O-acetyl-D-glucal via intramolecular Pauson-Khand (IPK) cycloaddition.

Abstract  In this letter, we report synthesis of branched polysaccharide 2 by glycosylation of glucal-type monomer 1 with two free hydroxy groups at position 3 and 4. Monomer 1 polymerized with N-halosuccinimide promoter in acetonitrile solvent at room temperature--50 degrees C. The product was isolated as a petroleum ether insoluble fraction. The structure was determined by 1H and 13C NMR spectra as well as elemental analysis to be a polysaccharide consisting of 2-halo-2-deoxy-alpha-D-mannoside units, indicating that the polymerization proceeded via stereoregular glycosylation manner. The molecular weights determined by GPC with DMF were 3,300-4,000. The degree of branching was estimated by the NMR data of the product from the reaction of 2 with 3,5-dinitrobenzoyl chloride.

Abstract  A method of capillary ion electrophoresis with indirect detection is developed for the simultaneous determination of the sulfur-containing anions S2O4(2-), S2O3(2-), SO4(2-), SO3(2-), and S2- and other anions (Cl-, Br-, NO2-, NO3-, (COO)2(2-), F-, and PO4(3-)) in the corrosion process. The effects of pH, tetradecyltrimethylammonium hydroxide, chromate, 2-[n-cyclohexylamino]-ethane sulfonate, calcium gluconate, and acetonitrile on the migration and resolution of the anions and the stability of sulfur-containing anions are systematically investigated. The detection limits, repeatability, and linearity for the anions are comparatively studied at 374, 274, and 254 nm, and the results show that 374 nm is the optimal length. The simultaneous multiwavelength detection at 374, 254, 214, and 195 nm can assist in confirming the identification of UV-absorbing anions.

Abstract  Two combinations of hurdles, 2.0% lactate+0.5% acetate or 2.0% lactate+0.25 % glucono-delta-lactone (GdL), were both found to prevent growth of Listeria monocytogenes inoculated onto sliced saveloys manufactured with 60 or 150 ppm nitrite. The saveloys were packed in modified atmosphere (80% N(2)/20% CO(2)) using a film with low oxygen transmission rate (0.45 cm(3)/m(2)/atm/24 h) and stored at 5 or 10°C for up to 4 weeks. Changes in red colour (measured as Minolta a-values) and lipid oxidation [measured as thiobarbituric acid reactive substances (TBARS)] were low during storage at 5°C and unaffected by the storage conditions (±light). However, 2.0% lactate+0.25% GdL improved oxidative stability and led to significantly lower TBARS and significantly higher a-values. Levels of nitrosamines were low with values near the detection level. Although observed differences were small, members of a trained sensory panel were able to distinguish saveloys containing chemical hurdles from saveloys without. Judges most often mentioned flavour as being the deviating descriptor.

Abstract  A glycoside hydrolase characterized by beta-fucosidase (EC 3.2.1.38) and beta-glucosidase (EC 3.2.1.21) activities was purified from the culture medium of the anaerobic ruminal phycomycete Neocallimastix frontalis grown on 0.5% Avicel. The enzyme had a molecular mass of 120 kilodaltons and a pI of 3.85. Optimal activity against p-nitrophenyl-beta-d-fucoside and p-nitrophenyl-beta-D-glucoside occurred at pH 6.0 and 50 degrees C. The beta-fucosidase and beta-glucosidase activities were stable from pH 6.0 to pH 7.8 and up to 40 degrees C. They were both inhibited by gluconolactone, sodium dodecyl sulfate, p-chloromercuribenzoate, and Hg cation. The enzyme had K(m)s of 0.26 mg/ml for p-nitrophenyl-beta-d-fucoside and 0.08 mg/ml for p-nitrophenyl-beta-d-glucoside. The purified protein also had low beta-galactosidase activity.

Abstract  Inhibition of Trichoderma reesei cellulase by sugars (glucose, delta-gluconolactone, and cellobiose) and solvents (ethanol, butanol, and acetone) was studied using cellulose azure. Glucose, cellobiose, ethanol, and butanol were noncompetitive inhibitors, delta-gluconolactone was a mixed inhibitor, and acetone was a noncompetitive activator. Converting cellobiose to glucose reduces the effective inhibitor binding constant by 6 times and converting cellobiose to ethanol reduces it by 16 times.

Abstract  A new metabolic pathway has been created in the microorganism Erwinia herbicola that gives it the ability to produce 2-keto-L-gulonic acid, an important intermediate in the synthesis of L-ascorbic acid. Initially, a Corynebacterium enzyme that could stereoselectively reduce 2,5-diketo-D-gluconic acid to 2-keto-L-gulonic acid was identified and purified. DNA probes based on amino acid sequence information from 2,5-diketo-D-gluconic acid reductase were then used to isolate the gene for this enzyme from a Corynebacterium genomic library. The 2,5-diketo-D-gluconic acid reductase coding region was fused to the Escherichia coli trp promoter and a synthetic ribosome binding site and was then introduced into E. herbicola on a multicopy plasmid. Erwinia herbicola naturally produces 2,5-diketo-D-gluconic acid via glucose oxidation, and when recombinant cells expressing the plasmid-encoded reductase were grown in the presence of glucose, 2-keto-L-gulonic acid was made and released into the culture medium. The data demonstrate the feasibility of creating novel in vivo routes for the synthesis of important specialty chemicals by combining useful metabolic traits from diverse sources in a single organism.

Abstract  A new medium, designated TMYGP broth, was developed that allowed the honeybee pathogen Bacillus larvae NRRL B-3650 to produce up to 5 x 10 spores per ml of culture (microscopic count). This species normally sporulates poorly, if at all, in artificial broth media. An aeration rate lower than that normally used to cultivate other Bacillus species was required for sporulation. During the exponential growth phase, acids were produced by catabolism of yeast extract components, causing a decrease in pH of the medium. Thereafter, the pH began to increase, probably because of derepression of the citric acid cycle and consumption of the acids. Only after this time did usage of glucose from the medium occur. Thus, glucose usage seems to be regulated by catabolite repression. The presence of glucose was needed for one or more of the later events of sporulation. Of many substances tested, only gluconic acid and glucosamine partially substituted for glucose as a requirement for sporulation. Pyruvate was also required for good sporulation. It was metabolized during the late-exponential phase of growth.

Abstract  The major water-soluble constituent of the defensive secretion of Eurycotis decipiens was identified as gluconic acid, isolated in the form of calcium D-gluconate. The acid, in equilibrium with its lactones, is present in unusually high concentration.

Abstract  The fact that fungal glucans will stimulate soybeans to accumulate phytoalexins prompted an investigation of soybean cell beta-1,3-glucanases and beta-glucosidases, as well as the ability of these enzymes to hydrolyze the fungal glucans. Several beta-1,3-glucanases and beta-glucosidases can be solubilized from the walls of suspension-cultured soybean cells by treatment with 1.0 molar sodium acetate buffer. An enzyme, which has been termed beta-glucosylase I, is the dominant beta-1,3-glucanase in the cell wall extracts. Utilizing CM-Sephadex chromatography, hydroxylapatite chromatography, and affinity chromatography, beta-glucosylase I has been purified 71-fold, with 39% recovery, from the mixture of cell wall enzymes. The affinity chromatography column material was prepared by covalently attaching p-aminophenyl-1-beta-d-glucopyranoside, an analog of a beta-glucosylase I substrate, to Sepharose. beta-Glucosylase I, purified by this procedure, yields a single band on isoelectric focusing gels (pH 8.9). However, the purified beta-glucosylase I yields a darkly-staining protein band at an apparent molecular weight of 69,000 and several lightly-staining protein bands in sodium dodecyl sulfate polyacrylamide gels. Additional purification procedures fail to remove these lightly-staining protein bands.beta-Glucosylase I will hydrolyze the beta-glucan substrates, laminarin (3-linked) and lichenan (3- and 4-linked), and therefore, possesses beta-glucanase activity. Studies of the progressive hydrolysis of laminarin by beta-glucosylase I demonstrate that the enzyme hydrolyzes polysaccharide substrates in an exo manner. beta-Glucosylase I will also hydrolyze a variety of low molecular weight beta-glucosides including various beta-linked diglucosides. Thus, beta-glucosylase I also possesses beta-glucosidase activity.Several lines of evidence are presented that the beta-glucanase and the beta-glucosidase activities exhibited by purified beta-glucosylase I preparations are catalyzed by the same enzyme. This evidence includes inhibition studies which indicate that the beta-glucanase and the beta-glucosidase activities of beta-glucosylase I are catalyzed at the same active site. beta-Glucosylase I will also catalyze glucosyl transfer. This catalytic activity is responsible for the observed ability of the enzyme to synthesize di- and trisaccharides from laminarin. The disaccharides formed by beta-glucosylase I-catalyzed transglucosylation are the beta-anomers of the 6-, 4-, 3-, and 2-linked diglucosides in the relative proportions of 10:1:1:1. The ability of beta-glucosylase I to catalyze glucosyl transfer indicates that beta-glucosylase I is biochemically more similar to previously studied beta-glucosidases than to beta-glucanases. This conclusion is supported by the observation that beta-glucosylase I is strongly inhibited by 1,5-d-gluconolactone, an inhibitor of beta-glucosidases but not of beta-glucanases.