Kernels of sweet corn (cv. Golden Cross Bantam and cv. Honey Bantam) and dent corn (cv. Pioneer dent corn and cv. White dent corn) were harvested at various development stages, and the IAA-related metabolites were analyzed quantitatively by HPLC. Metabolites 7-O-β-D-glucopyranosyl 3, 7-dihydroxy-2-indolinone-3-acetic acid (zeanoside A and C), 8-O-β-D-glucopyranosyl 8-hydroxy-2-quinolone-4-carboxylic acid (zeanoside B) and 8-hydroxy-2-quinolone-4-carboxylic acid (zeanic acid) were found in the corn kernels.
The content of zeanoside A and C in the corn kernels increased markedly at 20-30 days after silking, and then gradually decreased as the kernels matured. The content of zeanoside B in the corn kernels was highest in the at early stages and disappeared at 20-35 days after silking. Content of zeanic acid remained more or less unchanged at all development stages of the corn kernels.

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The initial stages of thermally-induced aggregation of cod myofibrils resulted from noncovalent inter molecular cross-linking as demonstrated by SDS electrophoresis. The nature of the noncovalent bonds was studied by introducing a zero length cross-linker, 1-ethyl-3-(3-dimethylamino propyl) carbodiimide (EDC). This allowed the examination of the noncovalent interactions by SDS electrophoresis and quantitative densitometry. Initially, during heating, about 50% of the myosin heavy chain was cross-linked to form a polymerized complex before the involvement of actin, regulatory proteins, or the myosin light chains. Inhibition of thermally-induced noncovalent crosslinking with triglycerides or Triton X-100 as well as the enhancement of aggregation at higher ionic strength, suggested the importance of hydrophobic interaction in this reaction.
Cod myosin heavy chains were prepared and the head regions labelled with the fluorescent probe, N-[7(dimethylamino)-4-methyl-3-coumarinyl] maleimide (DACM) which reacts specifically with two thiol groups near the active sites for Ca²⁺ and EDTA-ATPase. Chymotryptic cleavage of the thermally aggregated myosin heavy chains suggested the involvement of the tail region of the molecule rather than the head in the noncovalent cross-linking reactions.

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D-Glucosaminate dehydratase (EC 4.2.1.26) from Pseudomonas fluorescens (IFO 14808) was purified to homogeneity, as judged by the criterion of a single band on disc-gel electrophoresis. The enzyme (molecular weight 61, 000) consisted of two subunits identical in molecular weight (about 30, 000). Pyridoxal 5'-phosphate was an essential cofactor for the enzyme.
The enzyme catalyzed the dehydration of D-glucosaminate and of several D-and L-hydroxyamino acids. Especially when the concentration of substrate was low, D-serine was dehydrated at a rate similar to the rate of dehydration of D-glucosaminate. If both substrates were added to the reaction mixture at the same time, the rate of the reaction was additive until their individual concentrations reached to 0.2 mM level. However, as the concentrations of both the substrates were increased, the rate fell below the rate recorded with D-glucosaminate only. The kinetics of this reaction (in the presence of 1-10mM D-GlcNA) demonstrate that D-glucosaminate dehydratase is inhibited both noncompetitively (at low concentrations) and competitively by D-serine. From these and other observations, we postulate the presence of a binding site specific for D-serine on the enzyme.

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The selectivity coefficients of both the mono- and divalent forms of lysine for cation-exchange resins of the ammonium form were measured on the basis of the mass action law, and found to increase with decreasing divinylbenzene (DVB) content and also to increase with increasing temperature, while they remained constant in the concentration range of 0.05 to 0.6 mol/l at equilibrium. The signs of both the enthalpy and entropy changes for the ion-exchange are positive in this system. The selectivity coefficient for the monovalent form is well expressed by Gregor's model including the contribution of differences in the molar volume and osmotic pressure, and the results for the divalent form suggest the contribution of the change in the conformation of water which reflects both the positive entropy and enthalpy changes.

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The methionine (Met) action on serum cholesterol (Ch) and lipoprotein profiles was studied by varying the dietary carbohydrate sources in normal, hepatoma (AH109A)-bearing and Ch-loaded Donryu rats fed on 20% casein diets for 2 weeks. In normal rats, Met (1.8%) addition to a 20% casein diet containing a sucrose-starch (1:3) mixture increased HDL-Ch without affecting (VLDL + LDL)-Ch, and resulted in a significant reduction of the (VLDL + LDL)-Ch/HDL-Ch ratio (atherogenic index, AI), while Met showed no significant influence on them under dietary condition of sucrose alone or starch alone. In hepatoma-bearing rats, Met (1.2%) also had a significant influence only when the sucrose-starch mixture was used as the dietary carbohydrate source, the amino acid reducing AI by both suppressing the hepatoma-induced elevation in (VLDL + LDL)-Ch and increasing HDL-Ch. In Ch-loaded rats, however, Met (0.75 %) exerted no significant influence under the dietary carbohydrate source of the sucrose-starch mixture, but this amino acid significantly decreased (VLDL + LDL)-Ch without affecting HDL-Ch, and hence reduced AI under the dietary condition of sucrose alone or starch alone. These results suggest that dietary carbohydrates modulate the Met action on cholesterolemia depending on the absence or presence of dietary Ch, and that Met is essentially antiatherogenic from the aspect of lipoprotein profiles when the amino acid expresses significant influence on cholesterolemia in Donryu rats.

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Dimethyl sulfide (DMS) is volatile compound important as one of the characteristic flavor compounds of marine food products. The precursor of DMS in marine products is dimethyl-β-propiothetin (DMPT), which is abundunt in green algae. DMPT was effectively extracted by the use of hydrophilic solvents from dried hitoegusa (Monostroma nitidum), a green alga. At around pH 4 and at over pH 9, the extracted DMPT was rapidly degraded to DMS; at around pH 7.5, this degradation was much slower. The DMS obtained volatilized immediately from aqueous solution. However, when the DMPT was formed into a powder with dextrin and heated to release the DMS, 40-60% of the DMS remained in the powder. The amount of DMS remaining was 80 % when cyclodextrin was used to form the powder.

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Halotolerant killer yeasts which showed killer activity in the presence of NaCl were isolated from fermented foods, such as miso, soy sauce and salted vegetables, and identified as Debaryomyces hansenii, Hansenula anomala, Candida naeodendra and Pichia farinosa. The killer strains of C. naeodendra and P. farinosa were found here for the first time. Seventy-six percent of the salted vegetable samples contained killer yeasts, mainly D. hansenii. On the other hand, killer strains were isolated from 3 of 18 samples of miso and soy sauce. The killer spectra against the standard killer strains, K1-K10, were different from those of other killer strains reported previously.

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The killer toxin produced by the Pichia farinosa KKl strain was purified by ammonium sulfate precipitation, gel filtration, ion-exchange chromatography and reverse-phase HPLC. The molecular weight of the killer toxin was about 25 kd and its isoelectric point was 6.4. A significant amount of carbohydrate was not detected in the purified killer toxin, suggesting that the toxin is not glycosylated. Its N-terininal amino acid sequence showed no homology with other proteins. The stability and efficacy of the toxin's killer activity was examined. The toxin completely retained activity at pH 2.5-4.0 and 5°C, but lost activity at higher temperatures. Killer activity increased with increasing NaCl or KCl concentration, although NaCl was more effective than KCl.

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Trichoderma koningii, isolated from the roots and soil line of an ornamental Diffenbachia sp., yielded, when cultured on shredded wheat, a novel metabolite trivially named koninginin A. The compound is a ketal that weakly inhibits the growth of etiolated wheat coleoptiles at 10^-3 M, and is a white, finely crystalline compound with the molecular formula of C₁₆H₂₈O₄ and a melting point of 80-84°C. The structure has been established by UV, IR, ¹H NMR, ¹³C NMR, and MS.

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A microorganism producing transglutaminase was screened as an indication of hydroxamateform ing activity. The microbial transglutaminase was purified from the culture filtrate of the strain, S-8112, which was supposed to belong to the genus Streptoverticillium. The molecular weight of the purified enzyme was found to be about 40, 000 on SDS-polyacrylamide gel electrophoresis, the isoelectric point 8.9 and the optimal pH of the reaction 6-7. The present enzyme requires no calcium ions for its activity. Thus, it clearly differs from known transglutaminases derived from mammalian organs, which have been defined as calcium-dependent enzymes.

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α_s1-Casein and soybean globulins were polymerized and gelatinized by Ca₂₊-independent transglutaminase that was isolated from the culture filtrate of a microorganism thought to belong to Streptoverticillium sp. of actinomycetes. This enzyme polymerized such albumins as bovine serum albumin, human serum albumin and conalbumin in the presence of dithiothreitol. Rabbit myosin was polymerized by the present emzyme but actin was not. An RP-HPLC analysis after enzymic digestion of the polymerized α_s1-casein showed existence of the ε-(γ-Glu)Lys bond. Thus, it was confirmed that the polymerization was formed by a catalytic reaction of the transglutaminase.

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The effects of corn fiber intake (6 and 12 g/day for 10 days) on the fecal weight, moisture, neutral detergent fiber (NDF), pH, microflora and β-glucuronidase activity, and on the serum tipids were investigated in five healthy men. Fecal weight and NDF increased depending on the fiber dose, whereas fecal moisture decreased. No remarkable change in fecal microflora was observed. Fecal β-glucuronidase activities (per gram of wet feces and daily output) were dose-dependently decreased by corn fiber intake. The levels of serum lipids did not change. These results show that corn fiber intake yielded an increase of fecal weight and a reduction of fecal β-glucuronidase activity.

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DNA-synthesis stimulatory activity was found in some tryptic fragments of human β-casein by using BALB/c3T3 cells, and two of them were identified as the β-casein fragments of Arg[l] to Lys[18] (β-CN(f1-18)) and of Gln[105] to Lys[117] (β-CN(f105-117)).

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The methanol extract of Phellodendron amurense bark was shown to have a strong antifeedant activity against Reticulitermes speratus. The extract was sequentially partitioned with hexane, chloroform, ethyl acetate and water, and the activity was observed in both the chloroform and water fractions. The active principles isolated from the chloroform fraction were obacunone and kihadanin A, while those from the water fraction were berberine chloride and palmatine iodide.

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An attempt to enhance the transglycosylation activity of lysozyme was made by chemical modification. Computer simulation of the lysozyme-catalyzed reaction indicated that inhibition of the sugar residue binding to the binding subsite A caused a significant increase in transglycosylation activity. Therefore, the binary modification of Asp 101 and Trp 62 in hen egg white lysozyme was made in order to inhibit the sugar residue binding to subsite A. The modified lysozyme, in which the affinity of the sugar residue to subsite A was decreased by about 2kcal/mol of binding free energy change, increased the amounts of transglycosylation products in comparison with the native lysozyme. In particular, the octamer of N-acetylglucosamine was abundantly produced from the initial substrate, pentamer. The modified lysozyme should be useful for synthesis of oligosaccharides with a high degree of polymerization.

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The amylomaltase from Escherichia coli IFO 3806 was purified to homogeneity seen by SDSpolyacrylamide gel electrophoresis after DEAE-Sephadex, Ultrogel AcA 44, hydroxylapatite, and 1, 6-hexane-diamine-Sepharose 4B column chromatographies. The molecular weight of the purified enzyme was 93, 000 by SDS-polyacrylamide gel electrophoresis. The enzyme was most active at pH 6.5 and at 35°C, and stable up to 45°C at pH 7.0 and from pH 6.0-7.3 at 40°C on 30min incubation. The enzyme acted on maltotetraitol, maltopentaitol, and maltosylsucrose besides maltooligosaccharides, but did not act on maltitol, maltotriitol, glucosylsucrose, isomaltose, panose, isopanose, or isomaltosylmaltose. This enzyme did not catalyze hydrolytic action on maltotetraitol, maltopentaitol, or maltosylsucrose.

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The acceptor specificity of amylomaltase from Eschenchia coli IFO 3806 was investigated using various sugars and sugar alcohols. D-Mannose, D-glucosamine, N-acetyl-D-glucosamine, D-xylose, D-allose, isomaltose, and cellobiose were efficient acceptors in the transglycosylation reaction of this enzyme. It was shown by chemical and enzymic methods that this enzyme could transfer glycosyl residues only to the C4-hydroxyl groups of D-mannose, N-acetyl-D-glucosamine, D-allose, and D-xylose, producing oligosaccharides terminated by 4-O-α-D-glucopyranosyl-D-mannose, 4-O-α-D-glucopyranosyl-N-acetyl-D-glucosamine, 4-O-α-D-glucopyranosyl-D-allose, and 4-O-α-D-glucopyranosyl-D-xylose at the reducing ends, respectively.

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A sensitive kinetic determination of serum 5'-nucleotidase activity is described. Nucleoside oxidase catalyzes the oxidative coupling reaction of phenolic compounds and 4-aminoantipyrine to form colored substances in proportion of the amount of nucleoside. The present method relies on this phenomenon. Human serum 5'-nucleotidase was assayed using 5'-AMP as a substrate. When adenosine liberated was oxidized by nucleoside oxidase in the presence of phenolic compounds and 4-aminoantipyrine, a colored substance was formed at the same time. The rate of colored substance formation was proportional to the 5'-nucleotidase activity. The proposed method shows a low variation and a good correlation with the reference method. 3'-Nucleotidase was also assayed in a similar manner.

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Secondary alcohols (C₃ to C₁₀) were oxidized to the corresponding methylketones by resting mycelia of Scedosporium sp. A-4 grown on propane, but 3-pentanol and 3-hexanol were not oxidized. The oxidation of 2-propanol to acetone was inhibited by pyrazole, potassium cyanide, sodium azide and Hg²⁺. Alcohol dehydrogenase activity was found in the cell-free soluble fraction and this activity requires a cofactor, specifically NAD⁺. The oxidation of both 1-propanol and 2-propanol may be catalyzed by the same alcohol dehydrogenase.

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We separated three N^α-acetyltryptophan (Ac-Trp) derivatives formed through the reaction of Ac-Trp with hexanal, which is a major secondary product of lipid peroxidation. They were identified as 1-[N¹-(N^α-acetyltryptophano)]-1-(N^α-acetyltryptophan-2-yl)hexane (Trp-HL-1), 1, 1-bis[N¹-(N^α-aacetyltryptophano)]hexane (Trp-HL-2) and 1, 1-bis(N^α-acetyltryptophan-2-yl)hexane (Trp-HL-3). Hexanal became a cross-linker between two Ac-Trp molecules on the formation of these compounds. Since Trp-HL-1 contained a newly formed asymmetric carbon atom, its diastereomers, Trp-HL-1a and Trp-HL-1b, were separated and characterized by ORD.

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The effects of initial glucose concentrations on the cell growth, glucose usage, and human lysozyme (HLY) secretion under the ENO1 promoter were examined in the Saccharomyces cerevisiae strain A2-1-1A harboring a multicopy plasmid. By increasing the initial glucose from 2% to 10%, the HLY secretion increased 7-8 fold although the cell growth was not affected. By adding a mixture of mineral salts to the basal medium, the HLY secretion was increased about twice due to the continuity of the HLY expression at the stationary phase of cell growth.
The high HLY secretion (5.5 mg per liter, 47-fold higher than the original level) was achieved by the strain A2-1-1A grown in the synthetic basal medium containing 10% initial glucose, and supplemented with mineral salts containing ammonium suit ate, potassium phosphate, potassium chloride, magnesium sulfate, and iron sulfate.

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The stoichiometry of the reaction of bovine α₂-macroglobulin (α₂M) with a serine proteinase from Bacillus natto (BSP) showed that BSP bound to α₂M in a molar ratio of about 2:1. The α₂M-BSP complex hydrolyzed casein and succinyl-L-leucyl-L-leucyl-L-valyl-L-tyrosyl-4-methylcoumarin-7-amide (Suc-LLVY-MCA) 65 and 55% less, respectively, while the activity of fibrin hydrolysis was completely lost. The purified complex from DEAE-Toyopearl 650 S and Toyopearl HW-60 F chromatographies was homogeneous on polyacrylamide gel electrophoresis at pH 9.4. Immunoelectrophoresis of the α₂M-BSP complex showed weak cross-reactivity with an antiserum to BSP (anti-BSP). The specificity of α₂M-BSP complex to the acyl-LSTR-amide substrates Boc-LSTR-MCA and Boc-LSTR-pNA was partially changed. Enzymatic activity of the complex was completely abolished by chymostatin. Inactivation was observed when α₂M-BSP complex was incubated with a 5-molar excess of Streptomyces subtilisin inhibitor (SSI) at pH 7.5 and 20°C. Interaction of α₂M-BSP with ¹⁴C-succinyl-SSI was done at 20°C and at 4°C. Incorporation of ¹⁴C-succinyl-SSI with α₂M-BSP was faster at 20°C than 4°C

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The stored-product mite Suidasia medanensis has been found in human-provided habitats in Japan. The mite uses neral as the alarm pheromone, and also secretes (Z, E)- and (E, E)-farnesal, which were isolated from an astigmatid mite for the first time. On the other hand, S. medanensis is the only mite out of fifteen species investigated so far that does not secrete volatile hydrocarbons along with the alarm pheromone, though 9-nonadecene and 6, 9-nonadecadiene were found in a hexane extract of the mite. GC-MS, ¹H-NMR and ¹³C-NMR of the four isomers of synthetic farnesal, which were isolated by LC and preparative GLC, cleared up some confusion in the literature concerning the stereochemistry of this sesquiterpenoid.

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The total synthesis of (+)-methyl phaseate (2b) and its epimer (25) is described. The known β-ketoester (8), which was prepared from (-)-β-pinene (4), was converted to a key intermediate (5) via a 1, 4-dioxoester (7). The reaction of 5 with a lithium reagent of the acetylene TBDMS ether (6) in THF-HMPA at -70°C afforded the desired acetylene alcohol (17) and its epimer (18) in high yields. 17 was transformed into (+)-methyl phaseate (2b). From this synthetic work, the absolute configuration of natural (-)-phaseic acid (2a) was confirmed.

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Two insecticidal compounds were isolated from the seeds of Annona squamosa. One was identified as annonin (squamocin) and the other was characterized as a novel dihydroxy-bistetrahydrofuran fatty acid lactone (acetogenin) with 35 carbons. These two compounds were toxic to eggs, larvae and adults of the fruitfly.

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The influence of substituents on the activities of a series of N²-α-substituted benzyl-N⁴-alkyl-2, 4-diamino-6-chloro-s-triazines as inhibitors of photosystem II (PSII) was examined, and the phytotoxic differences between them and atrazine, as to the photosynthesis in leaf disks, mesophyll cells, intact chloroplasts and broken chloroplasts of spinach, and as to seedling-growth, were discussed. The inhibitory activity of the N²-α, α-dimethylbenzyl-N⁴-ethyl derivative (6), which was comparable on that of atrazine, was lower than those of the N²-α-alkylbenzyl analogues (1-5). The N⁴-n-alkyl-N²α-methylbenzyl derivatives, in spite of the carbon length of the alkyl group, exhibited more potent activity than atrazine, but an α or β substitution of the N⁴-n-alkyl group caused a decrease in the activity with a few exceptions. These data may imply that the space of the binding site on PSII surrounding both the N² and N⁴ amino groups is relatively large. The binding between the receptor site and the N⁴ amino group, however, is easily influenced by a slight structural change in an inhibitor. The herbicidal compounds, N²-α-methylbenzyl-N⁴-ethyl (1), N²-α, α-dimethylbenzyl-N⁴-1-methylpropyI (30) and N²-α-methylbenzyl-N⁴, N⁴-diethyl (42) derivatives, exhibited potent inhibitory activity in the seedling growth test under dark/light conditions, whereas atrazine was very poor. The inhibitory activity of compound (1) toward photosynthesis was poor with leaf disks, compared to atrazine, whereas, the order of their activities was the reverse for plant preparations such as abaxial epidermis peeled leaf disks, mesophyll cells, intact chloroplasts and broken chloroplasts. It was indicated that a change in the phytotoxic symptom in the whole plant assay would be correlated to the permeability of the compound through the plant membrane(s).

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Cells of an ice nucleation-active strain of Erwinia ananas were entrapped in calcium alginate to prepare an ice-nucleating gel usable as ice nuclei for freeze concentration. The ice-nucleating gel was also adjusted as to specific gravity. When it was placed at a desired position in a liquid material such as egg white, ice formed at this position as the material was cooled. It was possible to put the icenucleating gel in liquid foodstuffs such as egg white and lemon juice before their temperatures reached subzero points. Application of this method produced freeze-concentrated foods whose properties were not significantly deteriorated.

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The neutral protease of Bacillus subtilis var. amylosacchariticus was cleaved chemically or digested with proteolytic enzymes, and the resultant peptides were separated and purified by high performance liquid chromatography. The sequence analyses of these peptides by the manual Ed man procedure established the complete amino acid sequence of the enzyme. The neutral protease consisted of 300 amino acid residues with Ala and Leu as its amino- and carboxyl-termini, respectively, and the molecular weight was calculated to be 32, 633. The sequence was found to be identical to that of B. subtilis IA72 neutral protease, which was deduced from nucleotide sequencing. Comparison of the sequence with those of other Bacillus proteases revealed that the putative active site amino acid residues, Zn-binding ligands, and two Ca-binding sites were well conserved among them, as compared with those of thermolysin.

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The acid protease B of Scytalidium lignicolum (SAB) was modified with l, 2-epoxy-3-(4'-azido2'-nitrophenoxy)propane [EANP] under acidic conditions. EANP was incorporated stoichiometrically into SAB, and the enzyme was almost completely inactivated. The modified enzyme was digested with thermolysin and EANP-labeled peptides were separated by high performance liquid chromatography (HPLC). The amino acid sequence of the major peptide labeled was Ile-Leu-Glu-Thr-Gly, which corresponds to the sequence of residue Nos. 51-55 of the enzyme. Treatment of the peptide with 0.5 N hydroxylamine (pH 10.5) resulted in the complete removal of the modifier from the labeled peptide, suggesting that EANP is ester-linked to the Glu-53 residue of the enzyme. The amino acid sequence (-Cys-Gln-Thr-Ala-Ile-Leu-Glu-Thr-Gly-) around Glu-53 of SAB shows high homology with those around the active site aspartic acids of calf chymosin and porcine pepsin. The results indicate the involvement of Glu-53 in the enzyme reaction of SAB.

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A novel dioxygenase, lignostilbene-α, β-dioxygenase (LSD), which catalyzes cleavage of the interphenyl double bond of lignin-derived stilbenes, was isolated. Four isozymes of LSD were separated from cell-free extracts of Pseudomonas sp. TMY1009 by ion-exchange chromatography on a DEAE-Toyopearl column. The major isozyme, LSD-I, was purified to electrophoretic homogeneity and characterized.
LSD-I cleaved the interphenyl double bond of 1, 2-bis(4'-hydroxy-3'-methoxyphenyl)ethylene with the optimum pH at 8.5. The Km of LSD-I was 11 μM for the stilbene and 110 μM for oxygen. The molecular weight of LSD-I, which is composed of two identical subunits, was estimated to be 94, 000. LSD-I contained 1 g atom of iron per 1 mol of enzyme protein.

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Three inhibitory peptides of angiotension I-converting enzyme (ACE) were isolated from fresh latex of the fig tree (Ficus carica). The amino acid sequences of these peptides identified by the Ed man procedure and carboxypeptidase digestion were: Ala-Val-Asn-Pro-Ile-Arg, Leu-Tyr-Pro-Val-Lys, and Leu-Val-Arg. The IC₅₀ values of these peptides for ACE from rabbit lung were 13μM, 4.5μM, and 14μM, respectively. These peptides have been synthesized by the solid phase procedure, and the synthetic peptides were found to be identical with the natural inhibitors in their ACE inhibitory activities.

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The interaction of dietary protein (casein, soybean protein and milk whey protein) and fat (mold oil containing γ-linolenic acid, palm olein and safflower oil) on various lipid parameters were studied in rats consuming alcohol. Alcohol reduced the hypocholesterolemic effect of soybean protein and whey protein compared with casein. Safflower oil, compared with palm olein, reduced the plasma and liver cholesterol levels, whereas the effects of mold oil and palm olein were comparable. Casein promoted the desaturation of linoleic acid in the liver phosphatidylcholine compared with soybean protein; the effect of whey protein was comparable with that of casein. The aortic production of prostacyclin (PGI₂) was significantly higher in the casein group than in the soybean protein group, whereas dietary fat did not influence the protein effect. The effect of whey protein on the plasma concentration of prostaglandin E₂ was comparable with that of casein. Thus, different dietary proteins differently influenced various lipid parameters even in rats consuming alcohol.

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Ferredoxin-nitrite reductase [EC 1.7.7.1] has been purified to apparent homogeneity from rice (Oryza sativa cv. Kinmaze) leaves by a procedure used for the spinach enzyme [S. Ida and B. Mikami, Biochitn. Biophys. Acta, 681, 167 (1986)]. The rice enzyme consists of a single polypeptide of molecular weight of 60, 000 with 536 amino acid residues. The enzyme showed nearly identical absorption, circular dichroism, and magnetic circular dichroism spectra to those of the spinach enzyme, indicating the presence of the same prosthetic groups and protein conformation in both enzymes. The apparent Km values for nitrite and methyl viologen were 360μM and 63μM, respectively. The pH optimum was 7.6. These kinetic parameters are indistinguishable from those reported for spinach nitrite reductase. Monospecific antiserum against purified rice enzyme cross-reacted with nitrite reductases from a variety of higher plants and some phylogenetically divergent plants. Immunological comparisons indicated the rice enzyme is much more closely related to the other monocot enzymes in antigenic structure than to the dicot enzyme proteins. The results lend further support to our previous study [S. Ida, Plant Sci., 49, 111 (1987)] that spinach ferredoxin-nitrite reductase is serologically more related to the dicot enzymes than to the monocot nitrite reductases. Conspicuous differences between the rice and spinach enzymes were found in their molecular sizes and antigenicity. Relatedness of amino acid compositions of the enzyme proteins is discussed in relation to antigenic properties of ferredoxin-nitrite reductase.

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To clarify the role of hydroxyl group at C-3 position in sphingolipid, 3-deoxy analogs of sphingolipids were synthesized employing enzymatic resolution of α-amino acid as the key step.

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A sensitive and selective method was developed for the determination of 2-aminoethylphosphonic acid (AEP) and N-methyl AEP in animal tissues by gas chromatography (GC). These compounds were converted into their N-isobutoxycarbonyl methyl ester derivatives and measured by GC with flame photometric detection (FPD-GC), using 0.5% FFAP on Uniport HP as the GC column packing/The calibration curves for AEP and N-methyl AEP in the range of 0.02-2 μg were linear, and the detection limit was about 20 pg as an injection amount. AEP and N-methyl AEP in animal tissues were found in the free form and bound form with lipid and other biological macromolecules, and they could be measured without any influence from coexistent substances by FPD-GC. The recoveries of AEP and N-methyl AEP added to the tissue samples were 92-105%, and their reproducibility was found to be satisfactory. The distribution of these compounds in various animals was also studied by using this new method.

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Mutants of Saccharomyces diastaticus with defects in starch fermentation were isolated. In addition to the mutations in the STA1 structural gene for glucoamylase (sta1) and in the transcription factor (gam1), we recovered two new complementation groups, designated gam2 and gam3. These starch-nonfermenting mutants secreted little or no glucoamylase. The gam1 and gam2 mutants were pleiotropically defective in use of nonfermentable carbon sources, and consequently did not undergo meiosis and sporulation. No pleiotrophy was detected in the gam3 mutant. RNA blot analysis revealed that GAM2 and GAM3 are also required for transcription of STA1

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New acylated rhaponticin, a stilbene glycoside, was isolated as an antifouling substance against the blue mussel Mytilus edulis from the leaves of Eucalyptus rubida.

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