The effects of a diet containing fish oil with a low level of docosahexaenoic acid fed during the fetal to newborn stage on the learning ability of postnatal rats were evaluated. Learning ability estimated by the swimming test was superior with the fish oil group of 6-wk-old rats to that with the non-fish oil group. These findings suggest that the ingestion of fish oil, and especially of docosahexaenoic acid, during the period from the fetal to newborn stage, but not during the weaning period, and the accumulation of a large amount of dietary docosahexaenoic acid in the brain of fetal and newborn rats may be related to an improved cerebral function of postnatal rats.

View full abstract

The effects were determined of dietary fish oil on the polyunsaturated fatty acid desaturation in rats fed on fish oil-containing diets (FS group) and on non-fish oil diets (CN group) during the fetal to postnatal periods. Although the desaturase activity in the liver microsomes of the FS group was higher than that of the CN group before birth, this was not altered by dietary fish oil after birth. However, a lower 20 : 4n-6concentration before and after birth, and lower linoleic acid desaturation index ((dihomo-γ-linolenic acid + arachidonic acid)/linoleic acid)) at 10 wk of age in the FS group than in the CN group were observed in the liver microsomal phospholipids. The Δ6-desaturase activity in the brain microsomes of the FS group was lower than that of the CN group. These findings suggest that an intake of dietary fish oil by dams and postnatal rats affected the arachidonic acid concentration due to the decreased desaturase activity in the rats' microsomes.

View full abstract

Unlabeled D- and L-alanine were racemized in deuterium oxide with an alanine racemase of Bacillus stearothermophilus at saturated concentration of substrate, and various p²H and temperature. Samples of the solution were taken at intervals, and all alanine isomers in the samples were transformed into a mixture of diastereomeric derivatives of methyl N (-)-camphanylalaninate. Their ratio was measured on a GC-Mass, and the relative rate was calculated at the initial stage of the reaction. There was little difference in the decrease rate of the optical rotation between the enantiomers. Internal proton-transfer to the antipode was almost zero for either substrate. The α-hydrogen was abstracted 1. 2-2. 3 times faster from D-alanine than from L-alanine. D-Alanine gave an almost even mixture of deuterium labeled D- and L-alanine, while L-alanine gave a mixture of labeled D- and L-alanine at a ratio of 3 : 1. These results suggest the racemase builds two different bases in the active site. The base for D-alanine may be closer to the enzyme surface, and that for L-alanine inside.

View full abstract

Systolic blood pressure (SBP) decreased significantly when the hydrolysate of sake lee (HSL) and peptide fraction of sake (PFS) were orally administrated to spontaneously hypertensive rats (SHR). SBP of "young" SHR decreased significantly after orally administering Val-Tyr, His-Tyr, Arg-Phe, Val-Trp, and Tyr-Trp that were isolated from PFS and HSL. The hypotensive effect of Val-Tyr and His-Tyr that was observed in "young" SHR disappeared as they got older, but PFS and HSL maintained their antihypertensive effect on "aged" SHR. SHR fed on a diet with HSL replacing half of the protein source for 3 weeks showed a significant decrease in SBP after 10 days of feeding.

View full abstract

A microorganism producing a glucosyl transfer enzyme to hydroquinone was isolated from soil and identified as Bacillus subtilis according to its taxonomical characteristics. The enzyme (GSase) was puri-fied from the culture filtrate by column chromatographies, including affinity chromatography using Amylostatin-immobilized Sepharose 4B. The final preparation showed a single band on SDS polyacrylamide gel electrophoresis, the molecular weight being 67kDa. Its optimum pH for starch dextrinization was 7, while that for glucosyl transferring activity was 6, pH stability was 5-8, and isoelectric point was 5.1. GSase was not activated by Ca²⁺. It used malto-oligosaccharides and dextrin as well as soluble starch more effectively than maltose as glucose donors. It did not catalyze cyclodextrination from starch. GSase glucosylated various polyphenols, such as dihydroxy benzenes, hydroxy benzyl alcohols, phloroglucinol, (+)catechin, kojic acid, dihydroxy benzoic acids, caffeic acid, and gallic acid.

View full abstract

A DNA polymerase has been assayed from chloroplasts of petunia plants cultured in vitro. The enzyme activity depends on the presence of DNA and Mg²⁺ and is stimulated by K⁺. A single DNA polymerase band of 75 kDa was shown by SDS-polyacrylamide gel electrophoresis using a DNA-containing gel followed by in situ renaturation of proteins and incubation of the intact gel in a polymerase assay mixture. The enzyme activity was inhibited by N-ethylmaleimide (59% at 1mM) and dideoxythymidine triphosphate (25% at a ratio ddTTP/dTTP 1 : 1). The inhibitory effects of flavonoids on the DNA polymerase activity were studied. The glycosylation of hydroxyl groups on the flavonoids resulted in compounds that behaved as gradually weaker inhibitors with increased size of the substituent. The degree of inhibition decreased in the following order : quercetin > quercetin-3-L-rhamnoside > quercetin-3-rutinoside. Similarly baicalein-7-D-glucuronide was less active than baicalein. On the other hand, the number and position of hydroxyls of A ring was important for the inhibitory capacity. The flavonoids with a greater number of hydroxyl groups were more potent inhibitors of the chloroplast DNA polymerase.

View full abstract

A gramicidin S analog ([Orn^{1, 1'}]GS·4HCl) containing L-ornithine in place of L-valine at the 1, 1'positions was synthesized by the conventional solution method in order to examine whether this analog had antibacterial activity toward Gram-negative bacteria. In the synthesis of [Orn^{1, 1'}]GS·4HC1, two intermediate analogs ([Orn^{1, 1'}, Orn(For)^{2, 2'}]GS·2HCl and [Orn(Z)^{1, 1'}]GS·2HCl) were obtained. [Orn^{1, 1'}]GS·4HCl and [Orn^{1, 1'}, Orn(For)^{2, 2'}]GS·2HCl showed no activity toward either Gram-negative or Gram-positive bacteria, whereas [Orn(Z)^{1, 1'}]GS·2HCl showed appreciable activity toward only Gram-positive bacteria.

View full abstract

We cloned the cryIA(a) gene from Bacillus thuringiensis strain FU-2-7, one of the toxin genes encoding lepidopteran-specific protoxins. Sequence analysis of the gene showed two amino acid differences (Pro77 to Leu and Phe965 to Ser) from the CryIA(a) of B. thuringiensis strain HD-1. We constructed chimaeric cryIA(a) genes using FU-2-7 and HD-1 cryIA(a) genes and isolated the chimaeric protoxins, as well as the parental ones, from Escherichia coli cells harboring the recombinant plasmids to examine the effects of the two amino acid variations on the toxicity. FU-2-7 CryIA(a) protein was about half as toxic against the smaller tea tortrix, Adoxophyes sp., and one-third as toxic against the silkworm, Bombyx mori, as that of HD-1. On the other hand, a chimaeric CryIA(a) protein with a single replacement of Phe965 to Ser had nearly the same toxicity as the HD-1 CryIA(a) against the smaller tea tortrix and one-third the toxicity against silkworm as that of HD-1. This improved property of the chimaeric CryIA(a) protoxin may be useful for widening its application to crop protection in sericultural countries.

View full abstract

The freezing point curves and solubility curves for an aqueous solution of glycine or sodium glutamate with or without ethanol were measured, and the eutectic points of these solutions were estimated by the intersection of both curves. The addition of ethanol lowered the freezing point, the solubility, the eutectic temperature and the concentration of each amino acid solution. On the basis of these results, the freeze concentration of an aqueous solution of glycine was attempted on a pilot plant scale. The addition of ethanol greatly reduced the loss of glycine which was carried over during the separation of ice crystals by centrifuging.

View full abstract

Mouse macrophage (Mφ) hybridoma clones were generated by somatic cell hybridization of myeloma X63 cells (H-2^d) with C57BL/6 (H-2b) peritoneal exudate cells elicited with a streptococcal preparation, OK432, or thioglycollate medium. Although they hardly adhered to plastic dishes and could not be morphologically distinguished from parental X63 tumor cells, the clones retained Mφ characteristics. These included phagocytosis and production of lysozyme and nonspecific esterase, suggesting that they were hybridomas derived from Mφ. Some of them expressed various levels of Ia antigen and Fc receptor. Because they induced proliferation of T cells from Balb/c mice but not those from C57BL/6 mice, the Ia antigen of Mφ hybridoma was assumed to be derived from peritoneal Mφ. The level of proliferation induction was correlated to the level of Ia antigen expression. Several clones produced a factor that cytostatically inhibited growth of murine mammary carcinoma and was serologically identified with arginine deiminase.

View full abstract

The sequences of cDNA clones encoding the Bowman-Birk proteinase inhibitor (BBPI) and its isoinhibitors (D-II and C-II) have been identitied. Nucleotide sequence homologies among these clones and between the two reactive domains in each clone were very high. These homologies suggest that the BBPI and its isoinhibitor genes may have evolved from a common ancestral inhibitor. Also, clone pB2 (D-II) had two identical reactive sites that inhibit trypsin only, and three repetitive regions that are about 81bp and initiated with ATG. It was assumed from these results that isoinhibitor D-II was the most primordial type of these inhibitors.

View full abstract

To enhance the storage stability of essential oils such as d-limonene, a mixed powder of β-cyclodextrin and maltodextrin was used to encapsulate the liquid flavor in a powder state. In this study, powdery encapsulation of d-limonene was done by direct kneading of d-limonene with the mixed powder at low water content, using a twin screw kneader. The retention of d-limonene in the periodically sampled powder reached a maximum when the mass ratio of β-cyclodextrin to maltodextrin in the mixed powder equaled unity and the initial molar ratio of d-limonene to β-cyclodextrin was larger than unity. From X-ray diffraction of the powder, it could be guessed that the maximum retention of d-limonene might come from the adsorption of d-limonene upon maltodextrin. The equilibrium retention of d-limonene in the dry powder depended not only upon the mass ratio of β-cyclodextrin to maltodextrin in the mixed powder, but upon the initial moisture content in the powder. The equilibrium retention could be estimated well by a simple calculation.

View full abstract

The optimum electrotransformation conditions were determined for Pseudomonas putida PpY101 with plasmid pSUP104 (9.5kb) and pSR134 (18.6kb). Field strength was a very important parameter for electrotransformation efficiency. Optimum efficiencies (1.1x 10⁵ transformants/μg DNA) with pSUP104 and pSR134 were obtained at a field strength of 12. 5 kV/cm, a time constant of about 4.5 ms (resistance setting of 200 Ω), a supercoiled DNA concentration of 100 ng/ml, and a cell concentration of 10⁹/ml. Because the effciency obtained is high enough, electrotransformation is useful for the direct cloning of P. putida PpY101. No significant relationship between plasmid size and electrotransformation efficiency was observed. These efficiencies were about 4.5 times higher than those using the MgCl₂ method. Under these conditions, electrotransformation efficiencies of relaxed plasmid DNA treated with topoisomerase I and that linearized by EcoRI digestion were high.

View full abstract

The effects of green tea tannin on blood pressure were examined for rats with adenine-induced hypertension and renal failure. The systolic, mean, and diastolic blood pressure values were decreased by green tea tannin administration, whereas the urinary levels of kallikrein, prostaglandin E₂, and sodium were increased. No remarkable change was observed in the plasma renin activity. The angiotensin II and aldosterone levels were also unchanged in rats to which green tea tannin was administered. The mechanism for the depressor action of green tea tannin is discussed on the basis of these findings.

View full abstract

A nocardioform bacterium Rhodococcus sp. C-x, isolated from soil grew well on 1, 4-diguanidinobutane (DGB ; arcaine) as the sole nitrogen source. DGB was degraded to putrescine by a pathway with carbamoylagmatine (1-guanidino-4-ureidobutane), agmatine (1-amino-4-guanidinobutane), and carbamoylputrescine (1-amino-4-ureidobutane) as the intermediates. The enzymes of this pathway were partially purified from cells grown on DGB or agmatine and examined. The first and third steps of the degradation pathway of DGB were catalyzed by agmatine deiminase (EC 3. 5. 3. 12), which had relative activities of 100% and 30% toward agmatine and DGB, respectively. The second and fourth steps were catalyzed by carbamoylputrescine amidase (EC 3. 5. 1. 53), which had relative activities of 100%, 63%, and 12% toward carbamoylputrescine, carbamoylagmatine, and N-carbamoyl-β-alanine, respectively.

View full abstract

The cross-linking reaction and gelation of 11S globulins from soybean (glycinin) and broad bean (legumin) by Ca²⁺ -independent transglutaminase were studied. Analyses of the reaction products by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that only acidic subunits of both 11S globulins were polymerized through the formation ofintermolecular crosslinkings by transglutaminase. Gel permeation chromatography analyses found that there were no signiticant differences in the molecular weight distribution profiles of reaction products between glycinin and legumin. These results suggest that the crosslinking reactions of glycinin and legumin by transglutaminase progress in similar ways. On the other hand, rheological analyses such as dynamic viscoelastic measurements and compression tests indicated that gelation proceeded more rapidly and the values of hardness of formed gels were higher for glycinin compared with legumin. The water-holding capacity of the gels was significantly higher in the glycinin than in the legumin.

View full abstract

To get a closer insight into the substrate recognition of thermostable 3-isopropylmalate dehydrogenase (IPMDH) derived from Thermus thermophilus HB8, two analogs of the natural substrate, (2R, 3S)-3-isopropylmalic acid (IPM) were synthesized according to the chiral transcription methodology which we have recently developed, and the kinetics of the enzyme reaction were analyzed. 2-O-methyl IPM was found to be inactive as a substrate but to function as an uncompetitive inhibitor, which suggests that, although it is the site of oxidation by NAD ⁺, 2-O-methyl IPM was incorporated into one of the active sites of the homodimeric enzyme. The hydroxyl group at C-2 was not essential to the substrate recognition by IPMDH. The 1-carboxamide derivative of IPM was inactive, both as a substrate and as an inhibitor. This clearly implies the prime importance of electrostatic interaction between the C-1 carboxylate of IPM and a cationic function (probably a guanidino group of Arg-104) of the enzyme for the recognition of IPM.

View full abstract

Cluster analysis was done of the oxygenated compounds in cold-pressed oil (CPO) prepared from the flavedo of 45 Citrus cultivars. The compounds were classified into six main clusters. Pummelos formed two clusters containing mostly medium or larger sizes. Most of the sour Citrus fruits were placed in the pummelo clusters, but each of C. limon and C. sudachi formed a cluster that contained no other members. Isozymic analysis for peroxidase showed a band pattern of not more than three bands (P₁, P₂, and P₃) for the 42 Citrus cultivars tested. P₁ was the key band of the pummelo species. The confusion between pummelos and other fruits such as sour Citrus fruits in cluster analysis based on CPO components only was resolved on the basis of the zymograms of peroxidase followed by cluster analysis.

View full abstract

A sensitive assay of glutathione peroxidase activity by fluorometry with N-(9-acridinyl)maleimide was used to monitor the increase in GSSG with tert-butylhydroperoxide. The method was used to assay liver homogenates and human plasma samples, and was compared with a conventional coupled enzymatic method. The values, sensitivity, and precision of the new method were 1.0 to 1.6 times, 50 to 100 times, and 1.5 times, respectively, those by the conventional method.

View full abstract

Phosphatidylcholine hydroperoxide was assayed with phospholipase A₂ and glutathione peroxidase, based on fluorometry with N-(9-acridinyl)maleimide. The hydroperoxide was poorly reduced by glutathione peroxidase, and was converted by phospholipase A₂ into reactable forms of glutathione peroxidase. A linear relationship was found between hydroperoxides assayed by the enzymatic and chemical methods in the range from 0. 05 to 5. 0 nmol with 0. 5 to 1. 5 mg of the sample. The hydroperoxides of fatty acids, triacylglycerol and phosphatidylcholine were assayed in their mixtures and in commercial lecithins.

View full abstract

Two kinds of iron-containing proteins the molecular masses of which were about 10kDa and 24kDa were isolated from cytoplasmic fractions of Mycobacterium smegmatis grown under iron-sufficient (50μM Fe) and iron-overload (500μM Fe) conditions. Based upon the elution profiles in two chromatographic systems, spectrophotometric analysis, and ESR spectrum measurement, the protein of 10kDa met the criteria for classification as a ferredoxin. Another protein of 24 kDa showed no enzymatic activity, though its detailed structure was unknown. The ferredoxin and the protein of 24kDa contained about 30% and 50% of the total cellular iron, respectively, when cells were grown under the above conditions. The synthesis of the protein of 24kDa was, however, completely repressed in cells grown under iron-deficient (0.5μM Fe) conditions, although the ferredoxin was still synthesized to some extent even in iron-deficient cells. These results suggested that both ferredoxin and the protein of 24kDa could be synergistically involved in iron storage in this organism.

View full abstract

The bile acid sulfate sulfatase (BSS) produced by Pseudomonas testosteroni was purified and characterized. Chromatofocusing behavior and amino acid sequence over twelve amino acid residues from N-terminus of the enzyme indicated that BSS was composed of two isoforms of which molecular weights were 125, 000 and 103, 000. Each isoform was a homodimer of a subunit of which molecular weight was 53, 000 or 51, 000, respectively. The optimum pH was 8.5 and BSS was stable at pH 5. 8-8.0. The thermostability above 32°C was improved by the addition of polyols, such as sorbitol, sucrose, and glycerol. BSS was a Mn²⁺-dependent enzyme and contained 1-2 atoms of manganese in its own protein molecule. All 3α-sulfate esters of the bile acids routinely appearing in human serum were hydrolyzed by BSS to 3β-hydroxyl iso-compounds corresponding to each bile acid and sulfuric acid. We tentatively named this novel enzyme BSS (bile acid 3α-sulfate sulfohydrolase).

View full abstract

A recombinant chymosin was secreted at high levels using fusion genes with A. oryzae glucoamylase gene (glaA) and a wheat bran solid-state culture system. Two portions of the A. oryzae glucoamylase, one with almost the entire glucoamylase (GA1-603) lacking 9 amino acids at the carboxyl terminal, and the other (GA1-511) lacking the starch binding-domain, were fused in frame with prochymosin cDNA. Western blot analysis indicated that the mature chymosin was released from the secreted fusion protein by autocatalytic processing. The transformant harboring the GA1-511-prochymosin construct showed about 5-fold chymosin production of the transformant in which the chymosin gene was directly expressed under the control of the glaA promoter in submerged culture. Moreover, wheat bran solid-state culture gave about 500-fold higher yield of the chymosin (approximately 150 mg/kg wheat bran) compared with the submerged culture.

View full abstract

It is reported that nicotine, one of the major tobacco tar components, increases the acetylcholine level in the brain. As nerve growth factor (NGF) is thought to promote the differentiation and maintenance of cholinergic neurons in the brain that are damaged in Alzheimer's disease (AD) by the increment of acetylcholine synthesis, we studied the relationship between nicotine and various tobacco tar components and the NGF synthesis/secretion in cultured astroglial cells. We found that multi-phenol compounds and nicotine increased the NGF content in the conditioned medium. NGF induced by nicotine had the same biological activity, molecular weight, and antigenicity as mouse βNGF. Especially, nicotine potentiated the NGF-mediated survival of sympathetic nerve cells. Thus, in addition to its known excitatory effect on the central nervous system, nicotine also has the additional effects of stimulating NGF synthesis/secretion of astroglial cells and potentiating NGF action. This increased NGF in the brain may serve to promote neuronal survival.

View full abstract

Treatment of crowns of winter wheat (Triticum aestivum L. cv. Horoshirikomugi) with a low concentration of hydrogen peroxide (1 mM) in the presence of a specific inhibitor of catalase, 3-amino-1, 2, 4-triazole, induced or stimulated the synthesis of twenty-five polypeptides. Of the twenty-tive, two were found to be polypeptides that had previously been shown to be inducible by cold treatment. In addition to the twenty-tive polypeptides, two other new polypeptides were induced upon treatment with higher concentrations of hydrogen peroxide (5mM and 10mM) in the presence of AT. Conversely, the rates of synthesis of fourteen polypeptides were decreased by peroxide treatment. The observation that the synthesis of the same polypeptides is induced by low temperature and by treatment with hydrogen peroxide suggests the participation of active oxygen species in the changes in gene expression that occur during cold acclimation in winter wheat.

View full abstract

The cells of 28 strains of the Lactobacillus acidophilus group were evaluated for hemagglutination (HA) activity. The activity was found in the surface layer (SL) protein fraction extracted by 2M guanidine hydrochloride. The most SL proteins from the A group strains (L. acidophilus (A₁), L. crispatus (A₂), L. amylovorus (A₃), and L. gallinarum (A₄)) showed HA activity, but the proteins from the B group strains (L. gasseri (B₁) and L. johnsonii (B₂)) showed no activity. The SL proteins from the A group strains were composed in common of a main component having molecular mass of about 40-45 kDa on SDS-PAGE. The SL proteins from JCM 1034 strain that showed the highest HA activity was fractionted by CM-Toyopearl ion-exchange chromatography. The highest HA activity was detected in the major protein of 41 kDa. This protein was purified and shown to be composed of about 50% of hydrophobic amino acids. The HA activity of the protein (1034 lectin) was specifically inhibited by fetuin and bovine lactoferrin at the concentrations of 80 and 160μg/ml, respectively. The removal of N-acetylneuraminic acid from fetuin significantly decreased the inhibitory activity.

View full abstract

The TFIID complex, which is a general transcription factor, helps to activate and regulate the transcription associated with eukaryotic promoters. A TATA element-binding protein (TBP), a central subunit of the TFIID complex, binds to TATA elements. Circular permutation analysis showed that purified recombinant TBP-1 from Arabidopsis (aTBP-1) introduced a bend in DNA around a TATA element in DNA fragments in solution. The bending was a slow process. A bend in DNA caused by a TBP-1 was seen under an electron microscope, as was an aTBP-DNA complex after immunochemical staining.

View full abstract

S-Glycoproteins have been thought to play a role in the self-incompatibility in Brassica plants. Two cDNAs encoding S-glycoproteins were isolated from stigmas of two strains of Brassica campestris. Their amino acid sequences are highly homologous to each other. However, the numbers of the potential glycosylation sites are different, although most of them are conserved. In the middle part of the sequences, there are two supervariable regions which might contribute to the specificity of each S-glycoprotein. Genomic Southern analysis showed many bands hybridizing with cDNA of S-glycoproteins in various Brassica species including self-compatible species.

View full abstract

The difference in carotenoid components among various color types of soybean seeds, and the changes in carotenoid composition during seed development were examined by reverse-phase high-performance liquid chromatogrphy (HPLC). Lutein was the major carotenoid component in seed extracts from the common yellow soybean and from a variety having a black seed coat. Green soybean seeds contained several xanthophylls in addition to lutein. None of the mature soybean seeds contained β-carotene, a part from a trace amount being detected in a local variety of green soybean. The total carotenoid and lutein contents were higher in green soybeans than in the yellow types, and the estimated total amount of carotenoids correlates with that of chlorophylls. The thylakoid membrane residue in the plastids of green soybean had lost its functional lamella structure. Immature soybean seeds contained a green-vegetable type of carotenoids including α- and β-carotene. The amount of β-carotene decreased more rapidly than that of lutein and chlorophylls during seeds maturation. These results suggest that β-carotene, which acts as a photoprotective agent in developing seeds, is susceptible to degradation in the course of seed maturation.

View full abstract

Glucose dehydrogenase gene (gdh) mutants of Bacillus subtilis were construced using a derivative of the integration plasmid pJH101 to re-examine the previously reported result that glucose dehydrgenase was essential for triggering of spore germination. When spores were germinated in a complex medium containing glucose, the gdh-positive strain accumulated gluconate as the major metabolite, but no gluconate was found in the gdh mutant. Contrary to the previous study, our gdh mutant triggered spore germination normally on glucose in a minimal medium. Moreover a mutant having none of the activities for glucose dehydrogenase, glucose 6-phosphate isomerase, or glucose 6-phosphate dehydrogenase did not catabolized glucose, nevertheless the mutant triggered germination normally on glucose, thus it is concluded that neither of the major catabolic pathways for glucose is needed in germination triggering of B. subtilis spores.

View full abstract

When dextran sulfate was added at concentrations of 0.001% or 0.01% (w/v) to cultures of 3T3-L1 tibroblasts, their spontaneous adipose conversion was accelerated. The expression of a marker enzyme (glycerophosphate dehydrogenase) peaked on day 16 but later declined due to the cytotoxicity of dextran sulfate. Heparin had similar effects on adipose conversion.

View full abstract

An acetonic extract of Fagara xanthoxyloides LAM produced two compounds with strong ovicidal activity against Leptinotarsa decemlineata SANG. These compounds were isolated and identitied as fagaramide and pellitorine by their spectral data. The ovicidal activity of each was measured.

View full abstract

A single dose of ethanol was administered to rats with an osteogenic disorder (OD) and unable to synthesize ascorbic acid. The concentration of ascorbic acid in tissues did not increase, but the amount that was excreted in the urine increased. The increased urinary excretion was not caused by stimulation of ascorbic acid synthesis.

View full abstract

Melanoidin, which was obtained by the Maillard reaction between D-glucose and glycine, was found to exert a potent inhibitory effect on the activity of trypsin with BANA as a synthetic substrate. The concentration of melanoidin required to reduce the activity of trypsin by 50% was less than 1μg/ml, similar to that of soybean trypsin inhibitor and leupeptin. On the other hand, chymotrypsin was not affected by melanoidin. The specific interaction between melanoidin and trypsin is discussed.

View full abstract

From an acid hydrolysate of a neutral polysaccharide extracted and purified from a commercial preparation of Chlorella vulgaris K-22, a reducing monosaccharide was isolated and identitied as 3-O-methyl-D-galactose by the specific rotation, GLC-mass spectrometry, NMR spectroscopy, and H-NMR spectrum of an authentic specimen prepared from methyl D-galactoside.

View full abstract

Three distinct antimicrobial compounds were isolated from Brazilian propolis. These compounds were identified as 3, 5-diprenyl-4-hydroxycinnamic acid (1), 3-prenyl-4-dihydrocinnamoloxycinnamic acid (2), and 2, 2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (3). The respective antimicrobial activity, expressed as MIC in μg/ml, 1-3 against Bacillus cereus was 15. 6, 31.3, and 125 ; that against Enterobacter aerogenes was 31.3, 62.5, and 125 ; and that against Arthroderma benhamiae was 15.6, >250, and 62.5. Compound 1 is likely to be one of the major antimicrobial compounds in Brazilian propolis.

View full abstract

The nucleotide squence of the pectate lyase gene (pelK) from alkali-tolerant Bacillus sp. was identificated and analyzed. A 1, 260-base pair open reading frame for the pelK gene was observed and encoded for a protein of 420 amino acids. The signal peptide was composed of 21 amino acid residues. In the deduced primary structure of this enzyme, the three conserved regions of several pectate lyases were found and showed high homologies.

View full abstract

The Brassica napus genome contains more than four phosphoenolpyruvate carboxylase (PEPCase) genes. Although the nucleotide sequences of these genes highly resemble each otehr, an intron corresponding to the 7th intron in the maize gene is present in PE15- and PE105-PEPCase genes but absent in PE3-PEPCase. The intron corresponding to the maize 3rd intron is absent in PE15- and PE105-PEPCase genes. Deletion of these introns occurred precisely such that the coding sequence is faithfully preserved with respect to the maize gene. The PE19-PEPCase gene contains a deletion in the 8th exon instead of the presence of those introns.

View full abstract

As a step to breed a Saccharomyces cerevisiae strain able to produce ethanol directly from cellulose, we combined cDNA for Aspergillus aculeatus FI-CMCase (FI-carboxymethyl cellulase) with the GAP (glyceraldehyde-3-phosphate dehydrogenase) promoter of S. cerevisiae and used the resultant plasmid, pYEC91, to transform S. cerevisiae. The transformed cells produced active FI-CMCase within the cytoplasm. Western-blot analysis following SDS-polyacrylamide gel electrophoresis demonstrated that the cells contained a peptide having the same molecular mass and immunological identity as A. aculeatus FI-CMCase.

View full abstract

Chattonella marina is an ichthyotoxic red-tide plankton and the toxic mechanism of which has not been identified. Recently we reported that C. marina has a toxic effect against Vibrio alginolyticus mediated by oxygen radicals. In this study, we found that the amount of hydrogen peroxide increased 10- to 15-fold after the disruption of plankton cells. A small amount of H₂O₂ was constantly detected in plankton culture under normal growth conditions.

View full abstract

Carbohydrates from the bulb tissues of a hybrid between onion (Allium cepa) and garlic (Allium sativum) were fractionated into 70% ethanol-soluble and insoluble fractions. The substantial soluble fraction comprised a range of fructans, and the insoluble fraction contained large amounts of pectic substances (including 4-linked galactan) and highly branched xyloglucan, which is characteristic of dicotyledons rather than of monocotyledons in the cell-wall composition. The carbohydrates from the hybrid showed characteristics intermediate between onion and garlic.

View full abstract

A thermophilic Bacillus species producing extracellular lipase has been newly isolated from the soil of a Korean hot spring. The enzyme purified to homogeneity from the culture supernatant had high thermostability ; it did not lose activity upon incubation at 60°C for 30 min. The enzyme was fairly stable in the range of pH from 4 to 11, suggesting its usefulness for applications in organic synthesis.

View full abstract

Gibberellin-binding proteins (GBPs) were isolated from a crude extract of etiolated maize seedlings by affinity chromatography on gibberellin A₃(GA₃)-linked enhance-aminohexyl(EAH)-Sepharose 4B. The isolated proteins had a binding activity for [³H]-GA₄. The binding site with dissociation constant of 0. 5μM for GA₄ was detected in the proteins by the binding assay with the procedures of ammonium sulfate precipitation. The binding of [³H]-GA₄ to GBPs was reversible and could be inhibited by the addition of GA₁ and GA₃. An inactive gibberellin, GA₁₃, had no inhibitory effect on the binding of [³H]-GA₄ to GBPs.

View full abstract

cDNA encoding the 3'-terminal region of sweet potato feathery mottle virus (ordinary strain, SPFMV-O) RNA was cloned and sequenced. The 2324-bp cDNA contained an open reading frame (ORF) of 2066 bp followed by an 3' non-coding region and a poly(A) region. The ORF covered the coat protein and the carboxy terminus of the nuclear inclusion `b' protein (NIb).

View full abstract

For identification of how explosion increases the reactivity of chitin and chitosan, changes in the crystalline polymorphism of these polysaccharides were studied by X-ray diffraction measurements. The α-chitin form of chitin did not change after being exploded, but an X-ray diagram of chitosan showed a hydrated crystal of low crystallinity before the explosion, and increased crystallinity of the hydrated form plus a small amount of an anhydrous crystal after the explosion. The improvement of accessibility to both polysaccharides caused by the explosion seemed not to arise from changes in their crystalline polymorphism or crystallinity.

View full abstract

The effects of adding branched-chain amino acids to a nicotinic acid-free, low-protein diet on the conversion of tryptophan to nicotinamide were investigated in rats. The conversion ratio [urinary excretion of nicotinamide and its metabolites (μmol/day) x 1OO/tryptophan intake during urine collection (μmo1/day)] was significantly lower in the groups fed with the 3% Leu-, Val-, or Ile-added diet than in the group fed with the control diet. Namely, the inhibition of this conversion was observed not only by the addition of Leu, but also by the addition of Val or Ile. The addition of Ile and/or Val to the Leu-added diet did not antagonize the Leu effect.

View full abstract

To study the toxic interaction of grayanotoxin with Na-channel protein at the molecular level, a photoffinity and tritium-labeled grayanotoxin was synthesized via reductive amination of a benzaldehyde carrying the diazirino group and an amino derivative of the grayanotoxin.

View full abstract

Acetobacter polyoxogenes was transformed with plasmid DNA by electroporation. The following points were essential for transformation: (i) dilution of the culture broth with cold water and air bubbling of the culture broth for transformation at discharging from a jar fermentor, and (ii) selection of transformants by liquid cultivation. For shortening of the lag time in cultivation for selection of transformants, the following treatments were useful: (i) addition of sucrose to the cell suspension during transformation and to the broth for cultivation, and (ii) addition of 1mM MgCl₂ to a mixture of cells and DNA during electroporation.

View full abstract

NADH kinase exists in yeast mitochondria and phosphorylates NADH specifically. We obtained NADH kinase having high specificity and stability sufficient for the practical use from the aerobic yeast Pichia membranaefaciens. By using this enzyme, we succeeded in amplification of NADH without the influence of co-existing NAD⁺, by phosphorylating NADH into NADPH and putting this NADPH through an NADP⁺ -NADPH cycling system.

View full abstract

When L-arginine or L-serine at high concentrations found in the wintering plants was supplied to apple callus grown in modified White's basal medium, concentration-dependent inhibition of proliferation was observed. Some derivatives of these amino acids also inhibited the proliferation of the callus.

View full abstract