Showing papers in "Bioscience, Biotechnology, and Biochemistry in 1992"
589 citations
TL;DR: Dried bonito (Katsuobusi), a Japanese traditional seasoning made of bonito muscle was hydrolyzed by various proteases and the inhibitory activity of the hydrolyzates for angiotensin I-converting enzyme (ACE) [EC 3.4.15.1] was measured.
Abstract: Dried bonito (Katsuobusi), a Japanese traditional seasoning made of bonito muscle was hydrolyzed by various proteases and the inhibitory activity of the hydrolyzates for angiotensin I-converting enzyme (ACE) [EC 3.4.15.1] was measured. Among the digests, thermolysin digest showed the most potent inhibitory activity. Eight inhibitory peptides were isolated from the digest using HPLC. The amino acid sequences of inhibitory peptides were Ile-Lys-Pro-Leu-Asn-Tyr, Ile-Val-Gly-Arg-Pro-Arg-His-Gln-Gly, Ile-Trp-His-His-Thr, Ala-Leu-Pro-His-Ala, Phe-Gln-Pro, Leu-Lys-Pro-Asn-Met, Ile-Tyr, and Asp-Tyr-Gly-Leu-Tyr-Pro. By searching for the sequence homology in many proteins, four of them were found in the primary structure of actin. Asp-Met-Ile-Pro-Ala-Gln-Lys was obtained from the boiling water extract of dried bonito and this peptide was found in the primary structure of creatine kinase. Fragments of these peptides were prepared by further enzymatic digestion or chemical synthesis and their ACE-inhibitory activities were measured. Among them, Ile-Lys-Pro, Ile-Trp, Leu-Lys-Pro, and Leu-Tyr-Pro had higher inhibitory activity than their parental peptides. Ile-Lys-Pro suppressed the hypertensive activity of angiotensin I.
288 citations
TL;DR: An extracellular phytase from Bacillus subtilis (natto) N-77 was purified 322-fold to homogeneity with the specific activity of 8.7 units per mg protein by ultrafiltration, and a combination of Sephadex G-100 and DEAE-Sepharose CL-6B column chromatographies, suggesting that the native enzyme is a monomeric protein.
Abstract: An extracellular phytase from Bacillus subtilis (natto) N-77 was purified 322-fold to homogeneity with the specific activity of 8.7 units per mg protein by ultrafiltration, and a combination of Sephadex G-100 and DEAE-Sepharose CL-6B column chromatographies. The molecular weight of the purified enzyme was estimated to be 36 kDa on gel filtration and 38 kDa on SDS-polyacrylamide gel electrophoresis, suggesting that the native enzyme is a monomeric protein. The enzyme had the isoelectric point of pH 6.25, and Ca2+ requirement for the production and activity, the Km value of 0.5 mM, and the activation energy of 9.87 kcal/mol for sodium phytate. The enzyme proved to be fairly specific for phytate and was most active at pH 6.0–6.5 and 60°C. Its activity was greatly inhibited by reagents and metal ions such as EDTA, Zn2+, Cd2+, Ba2+, Cu2+, Fe2+, and Al3+.
248 citations
TL;DR: Hydrolytic degradation of PGA was found to proceed through a random chain scission and a by-product was produced, which seemed to be a polysaccharide.
Abstract: Poly(γ-glutamic acid) (PGA) production in Bacillus subtilis IF03335 was studied. When citric acid as a carbon source was added to a glutamic acid medium containing L-glutamic acid and ammonium sulfate, a large amount of pure PGA was produced. On the other hand, when glucose was added to the glutamic acid medium, a by-product was produced, which seemed to be a polysaccharide. Moreover, the mode of hydrolysis was investigated with PGA in aqueous solutions at 80, 100, and 120°C by monitoring the time-dependent changes in the molecular weights. Hydrolytic degradation of PGA was found to proceed through a random chain scission.
208 citations
TL;DR: The preliminary examination of allyl iso-isothiocyanate vapor for food preservation is described in this article, where the authors present a preliminary evaluation of the vapor for preservation.
Abstract: (1992). Preliminary Examination of Allyl Isothiocyanate Vapor for Food Preservation. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 9, pp. 1476-1477.
204 citations
182 citations
TL;DR: In this article, the components responsible for undesirable taste in soybeans have been investigated and intensities of undesirable taste were measured by electrophysiological methods, which showed that the mechanism of undesirable tastes caused by soybean saponins was likely to be different from those of basic tastes (sweet, salty, sour, and bitter).
Abstract: The components responsible for undesirable taste in soybeans have been investigated and intensities of undesirable taste were measured by electrophysiological methods. Bitterness and astringency in soybeans were shown to be caused by soybean glycosides such as saponins and isoflavones, and the soybean sapponin A group contributes most strongly to the undesirable taste. In the three electrophysiological methods to measure intensity of undesirable tastes, soybean saponins did not induce the membrane potential change of neuroblastoma cells (N-18 clone) and the electrical response of the chorda tympany nerve of rats, and only the electrical response of the glossopharyngeal nerve of the frog was induced by soybean saponins. These results showed that the mechanism of the undesirable tastes caused by soybean saponins was likely to be different from those of basic tastes (sweet, salty, sour, and bitter).
177 citations
TL;DR: (1992).
Abstract: (1992) Nucleotide Sequence of the Subtilisin NAT Gene, aprN, of Bacillus subtilis (natto) Bioscience, Biotechnology, and Biochemistry: Vol 56, No 11, pp 1869-1871
156 citations
TL;DR: Differences in the structure between the two immunoglobulins that might participate in their different stability were inferred from their amino acid sequence data and some other structural differences were suggested.
Abstract: Molecular stability of chicken egg yolk immunoglobulin G (IgY) and that of rabbit IgG were compared by measuring antibody activities and conformational changes Stability of rabbit IgG to acid denaturation was much higher than that of IgY Conformation of the IgY molecule was readily changed in acidic conditions, resulting in a rapid loss of antibody activity Much less stable natures of IgY to heat-treatment and guanidine-HCl denaturation than rabbit IgG were also observed Differences in the structure between the two immunoglobulins that might participate in their different stability were inferred from their amino acid sequence data Importance of the intramolecular disulfide linkage in the rabbit light chain and some other structural differences were suggested
137 citations
136 citations
TL;DR: 1-(6-Chloronicotinyl)-2-nitroimino-imidazolidines and Related Compounds as Potential New Insecticides
Abstract: (1992). 1-(6-Chloronicotinyl)-2-nitroimino-imidazolidines and Related Compounds as Potential New Insecticides. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 2, pp. 364-365.
TL;DR: Compared to commercial emulsifiers, the casein-polysaccharide conjugates showed better emulsifying properties in acidic and high-salt concentration systems.
Abstract: Casein was conjugated with dextran and galactomannan in a controlled dry state at a relative humidity of 79% and at 60°C for 24 hr. The covalent attachment of polysaccharides to casein was confirmed by SDS-PAGE and HPLC. The emulsifying activity of the casein-dextran and casein-galactomannan conjugates was 1.5 times higher than that of casein. The emulsion stability of the casein-dextran and casein-galactomannan conjugates was 10 times higher than that of casein. The improvement in these emulsifying properties reached a steady state when the conjugation of casein with polysaccharide was done for 24 hr in a controlled dry state, suggesting the rapid formation of conjugates through a Maillard reaction in the case of casein. Compared to commercial emulsifiers, the casein-polysaccharide conjugates showed better emulsifying properties in acidic and high-salt concentration systems.
TL;DR: The Acidic and neutral fractions of an extract of the marine alga, Eisenia bicyclis (Japanese name “Arame”), showed strong antioxidative activity when tested by the ferric thiocyanate and TBA methods, and the porphyrin ring system seems to be important for the antioxidants activity in the dark.
Abstract: The Acidic and neutral fractions of an extract of the marine alga, Eisenia bicyclis (Japanese name “Arame”), showed strong antioxidative activity when tested by the ferric thiocyanate and TBA methods. Chromatographic purification of the neutral fraction gave an active oily substance identified as pyropheophytin a, one of the chlorophyll a-related compounds. This compound showed higher antioxidative activity than α-tocopherol and could be expected to act as an antioxidant in foods. The porphyrin ring system seems to be important for the antioxidative activity in the dark.
TL;DR: The tea polyphenols had no effect on fecal enzyme activities, ammonia, or putrefactive products, and the microflora counts and their biological parameters appeared to have returned to normal.
Abstract: Effects of tea polyphenol intake (0.4 g/volunteer, 3 times per day, for four weeks) on fecal microflora, bacterial metabolites, and pH were investigated using eight healthy human volunteers. Counts for Clostridium perfringens and other Clostridium spp. were significantly decreased during the tea polyphenol intake periods. Percentage of volunteers having C. perfringens in their feces decreased significantly, but not for other Clostridium spp. Percentage of Bifidobacterium spp. (the acid forming bacteria) in total counts and the content of volatile fatty acids including acetic and propionic acids increased significantly, which might have reduced the fecal pH. However, the tea polyphenols had no effect on fecal enzyme activities, ammonia, or putrefactive products. Two weeks after discontinuing the intake, the microflora counts and their biological parameters appeared to have returned to normal.
TL;DR: Five extracellular endo-xylanases were recognized in the culture broth of shochu koji mold (Aspergillus kawachii, IFO 4308), and three major xylanases (XylA, XylB, and XylC) were purified and characterized and found to be greatly different in their properties.
Abstract: Five extracellular endo-xylanases were recognized in the culture broth of shochu koji mold (Aspergillus kawachii, IFO 4308), and three major xylanases (XylA, XylB, and XylC) were purified and characterized. The molecular masses of XylA, XylB, and XylC were 35,000, 26,000, and 29,000, and isoelectric points were pH 6.7, 4.4, and 3.5, respectively. Amino acid compositions and other properties were studied and these three xylanases were found to be greatly different in their properties. These three xylanases, XylA, XylB, and XylC, were stable between pH 3-10, 3-10, and 1-9 and the optimum pHs were 5.5, 4.5, and 2.0, respectively. Consequently, these xylanases were acid stable xylanases, especially XylC was an acidophilic xylanase (acid xylanase). These xylanases produced various xylooligosaccharides including xylose from xylan and the main product was xylobiose in all xylanases. The production of acid xylanase (XylC) was enhanced with a low initial pH of the medium.
TL;DR: The competitive binding assay demonstrated that both Lf and GMP inhibited the binding of CT to GM1, although their affinity for CT was lower than that of GM1.
Abstract: Inhibition from binding of Cholera toxin (CT) to Chinese hamster ovary (CHO)-K1 cells and ganglioside GM1 by lactoferrin (Lf) and K-casein glycomacropeptide (GMP) from cow’s milk was examined. Both Lf and GMP effectively reduced the CT-derived morphological changes in CHO-K1 cells. The competitive binding assay demonstrated that both Lf and GMP inhibited the binding of CT to GMH although their affinity for CT was lower than that of GM1. The inhibitory effect of Lf and GMP seemed to be attributed to their terminal sialic acid, although the sugar chain sequence only partially fitted to the CT-receptor.
TL;DR: The crystalline polymorph called "1-2", which has been proposed to be one of four chitosan polymorphs, is considered to be a mixture of hydrated and anhydrous crystals.
Abstract: Differences in the polymorphism and crystallinity of chitosan were found in membranes prepared by different procedures when examined by X-ray diffraction measurements for four samples of chitosan differing in the degree of polymerization. When an acetic acid solution of chitosan was dried in air and then soaked in an alkaline solution (method A), both hydrated and anhydrous polymorphs of chitosan were present in the resulting membranes; the latter polymorph made chitosan insoluble in common solvents of chitosan, and its crystallinity increased with decreasing chitosan molecular weight. When a highly concentrated chitosan solution in aqueous acetic acid was neutralized with an alkaline solution (method B), no anhydrous polymorphs were detected in the membrane because of incomplete drying. When aqueous formic acid was used as the solvent, behavior basically similar to that in aqueous acetic acid was observed. In contrast, even with method A, aqueous hydrochloric acid gave a chitosan membrane having very little anhydrous crystallinity. The crystalline polymorph called "1-2", which has been proposed to be one of four chitosan polymorphs, is considered to be a mixture of hydrated and anhydrous crystals.
TL;DR: In this article, the authors describe the isolation and structural elucidation of the major Genuine Soybean Saponin, which is the most widely used soybean saponin.
Abstract: (1992). Isolation and Structural Elucidation of the Major Genuine Soybean Saponin. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 1, pp. 142-143.
TL;DR: The transformed yeast with a cloned cDNA produced xylanase, a major component of thexylanase family, from Aspergillus kawachii, and the genomic DNA was arranged as ten exons and nine introns.
Abstract: We have cloned the xynA gene coding for xylanase A, a major component of the xylanase family, from Aspergillus kawachii. The cDNA was isolated from an A. kawachii cDNA library by immunoscreening using antibody raised against the purified xylanase A protein. Nucleotide sequence analysis of the cDNA showed a 981-bp open reading frame that encoded a protein of 327 amino acid residues. The signal peptide was composed of 25 amino acid residues and the N-terminus of the mature protein was pyroglutamic acid. The transformed yeast with a cloned cDNA produced xylanase. The genomic DNA was arranged as ten exons and nine introns.
TL;DR: A main pungent amide, spilanthol, and three alkamides, (2E)-N-(2-methylbutyl)-2-undecene-8,10-diynamide, new and new, were found for the first time in Spilanthes species.
Abstract: A main pungent amide, spilanthol (1), and three alkamides, (2E)-N-(2-methylbutyl)-2-undecene-8,10-diynamide (2), (2E,7Z)-N-isobutyl-2,7-tridecadiene-10,12-diynamide (3), and (7Z)-N-isobutyl-7-tridecene-10,12-diynamide (4) were isolated from the flower heads of Spilanthes acmella L. var. oleracea Clarke. Their structures were established by spectroscopic methods. Compounds 2 and 4 were new and 3 was found for the first time in Spilanthes species. Chemotaxonomic aspects are discussed.
TL;DR: In this paper, the Extracellular Levansucrase from Zymomonas mobilis was purified, crystallized, and used for protein synthesis and the properties of the extracellular leucosucrase were investigated.
Abstract: (1992). Purification, Crystallization, and Properties of the Extracellular Levansucrase from Zymomonas mobilis. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 8, pp. 1335-1337.
TL;DR: Results indicate that Bacillus sp.
Abstract: The hydrolyzate of partially N-acetylated chitosan by Bacillus sp. No. 7-M chitosanase was separated by gel filtration on Bio-Gel P-2. Sugar compositions and sequences of the oligosaccharides were identified by exo-splitting with β-GlcNase, fast atom bombardment mass spectroscopy, and proton NMR spectroscopy_ In addition to chitooligosaccharides, (GlcN)2, (GlcN)3, and (GlcN)4, hetero-chitooligosaccharides such as (GlcN)2, GlcNAc (GlcN)2, GlcN GlcNAc (GlcN)3, (GlcN)2 GlcNAc (GlcN)3, and GlcN GlcNAc (GlcN)4 were detected. These results indicate that Bacillus sp. No. 7-M chitosanase is absolutely specific toward the GlcN GlcN bonds in partially N-acetylated chitosan and at least three GlcN residues were necessary to the hydrolysis of chitosan by chitosanase.
TL;DR: The effects of green tea polyphenols, inhibitors of various biological activities of cariogenic bacteria in vitro, on caries development were examined using conventional rats and total fissure caries lesions was significantly reduced.
Abstract: The effects of green tea polyphenols, inhibitors of various biological activities of cariogenic bacteria in vitro, on caries development were examined using conventional rats. A total of 96 male rats were divided into 8 groups and the rats in the test groups were given tea polyphenols ranging from 0.1% to 0.5% in their cariogenic diet or drinking water for 40 days. Total fissure caries lesions was significantly reduced by the addition of tea polyphenols to the diet or in the drinking water. Diet containing 0.1% tea polyphenols demonstrated about 40% reduction of total fissure caries lesions. No toxic effect of tea polyphenols on rats were observed under these experimental conditions.
TL;DR: In this paper, 1-(6-Halonicotinyl)-2-nitromethylene-imidazolidines as potential new insecticides are presented as new potential insecticides.
Abstract: (1992). 1-(6-Halonicotinyl)-2-nitromethylene-imidazolidines as Potential New Insecticides. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 2, pp. 362-363.
TL;DR: Levansucrase (EC 2.4.1.10) was purified to homogeneity from cell-free extracts of Rahnella aquatilis JCM-1683 by streptomycin treatment, ammonium sulfate fractionation, and HPLC with a DEAE-Toyopearl pak 650M, TSK gel G-3000SW, and TSKgel DeAE-5PW.
Abstract: Levansucrase (EC 2.4.1.10) was purified to homogeneity from cell-free extracts of Rahnella aquatilis JCM-1683 by streptomycin treatment, ammonium sulfate fractionation, and HPLC with a DEAE-Toyopearl pak 650M, TSKgel G-3000SW, and TSKgel DEAE-5PW. The enzyme had optimum activity around pH and 55—60°C. The molecular weight of the enzyme was 120,000 on gel filtration and it was composed of two identical subunits (64,000). The amount of levan synthesized by the purified enzyme was 2.95 g from 10.0g sucrose. The enzyme had a broad acceptor specificity and gave transfer products. D-Xylose, D-arabinose, L-arabinose, lactose, maltose, maltotriose, cellobiose, and melibiose were effective acceptors in the transfructosylation reaction of the enzyme.
TL;DR: In this paper, cross-activity between Pheromone Biosynthesis Activating Neuropeptide (PBAN) and myotropic Pyrokinin Insect Peptides was investigated.
Abstract: (1992). Cross-activity between Pheromone Biosynthesis Activating Neuropeptide (PBAN) and Myotropic Pyrokinin Insect Peptides. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 1, pp. 167-168.