A spectrophotometric method is proposed for the quantitative determination of quinidine. The method is based on solvent extraction of quinidine and tetrabromophenol-phthalein ethyl ester together into dichloroethane. Quinidine was found to form an addition-compound with the reagent in the organic solvent. Quinidine is determined by measuring the absorbancy of the extracts within the concentration range from 1.6×10^-6 to 8.0×10^-6M. The effect of diverse substances and the composition of the colored species were also investigated.

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To investigate the growth response of HeLa cells for various amino acid balances, the cells were kept on monolayer culture in media in which levels of 12 kinds of amino acids were increased or decreased. The balance and level of amino acids for the maximum growth of the cells were closely resembled to those of Eagle's minimum essential medium (MEM).¹⁾ Within lower levels of amino acids than those of MEM, the growth rate of the cells depended on the concentration of the most limiting amino acid in the medium, and on the concentration of the most limiting amino acid in the cells. Like whole animals, the amino acid pattern for the maximum growth under definite nitrogen levels also differed between low and optimum levels of amino acids. Neither antagonistic nor cooperative relationship between amino acids such as leucine-isoleucine or lysine-arginine antagonism was observed on the cell growth within these experimental conditions of amino acid balances. Unlike whole animals, addition of an amino acid excessively to the low amino acid medium did not inhibit the growth of the cells, and no imbalance phenomenon was observed in vitro.

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¹⁴C-Labelled showdomycin was rapidly taken up by Escherichia coli K-12 cells. The showdomycin uptake was highly temperature dependent, sensitive to azide and N-ethyl-maleimide, but was only partially inhibited by treatment with high concentration of iodoacetie acid.
The uptake of showdomycin was inhibited by a wide variety of nucleosides but not by purine and pyrimidine bases, nucleotides, ribose or ribose-5-phosphate. The inhibition of showdomycin uptake by adenosine was of a competitive type.
Since nucleosides inhibited the uptake of showdomycin but did not facilitate its efflux, they must play a role of inhibitors to the entry of the antibiotic into cells. Removal of extracellular showdomycin by washing, or inhibition of its subsequent entry into cells by the addition of nucleosides or sulfhydryl compounds resulted in a rapid decrease in the intracellular level of the antibiotic during subsequent incubation.

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Threonine aldolase was found to be formed in various strains of bacteria and yeasts when they were grown in media containing L-threonine as a sole source of carbon. As the other sources of carbon, D, L-allothreonine, L-serine and glycine were effective but glucose and sucrose were inert for the formation of the enzyme.
The maximal formation of the enzyme was observed in the initial of stationary phase of growth and, thereafter, the enzyme disappeared with the consumption of L-threonine. It seems that the enzyme is adaptive in nature and that it is responsible for the growth in threonine as the carbon source.

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An enzyme which synthesizes ureido ring of biotin or desthiobioin from biotin diaminocarboxylie acid or 7, 8-diaminopelargonic acid, respectively, was purified about 2000-fold against the crude extract from Pseudomonas graveolens by a procedure involving ammonium sulfate fractionation, and DEAE-cellulose, hydroxylapatite and Sephadex G-200 column chromatographies. The final enzyme preparation showed a nearly symmetric peak upon ultracentrifugation.
The pH optimum of the enzyme was found to be at 7.0 to 8.0. On heating, the en-zyme was stable up 45°C, but, above 55°C, it was rapidly destroyed. Requirements for the enzyme reaction included bicarbonate, ATP and Mg²⁺, as well as biotin diamino-carboxylic acid or 7, 8-diaminopelargonic acid as substrate. The activity of the enzyme to form ureido ring from biotin diaminocarboxylic acid was one tenth of that from 7, 8-diaminopelargonic acid. 7-Keto-8-aminopelargonic acid and 7-amino-8-ketopelargonic acid were inactive as the substrate.

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In the late phase of φX174 infection, DNA was pulse-labeled and the incorporated label in RF II was chased. In resting RF II as well as active RF II there existed short DNA chains smaller than one-unit length of a linear φX174 DNA. The molecular sizes varied from 5 to 12 s as scdimented through sucrose gradients in alkaline conditions. Possible mechanisms of synthesis of φX174 progeny DNA are discussed.

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The transglucosidation reaction of brewer's yeast α-glucosidase was examined under the co-existence of L-sorbose and phenyl-α-glucoside. As the transglucosidation products, three kinds of new disaccharide were chromatographically isolated. It was presumed that these disaccharides consisting of D-glucose and L-sorbose were 1-O-α-D-glucopyranosyl-L-sorbose ([α]_D+89.0), 3-O-α-D-glucopyranosyl-L-sorbose ([α]_D+69.1) and 4-O-α-D-glucopyranosyl-L-sorbose ([α]_D+81.0). The principal product formed in the enzyme reaction was 1-O-α-D-glucopyranosyl-L-sorbose.

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The effect of a borate on the isomerization reaction between glucose and fructose which is catalyzed by a glucose isomerase was investigated. The yield of fructose was dependent on both the ratio of sugar to the borate and pH. A maximum of 88 to 90% of glucose was converted into fructose when the isomerization reaction was carried out at around pH 7.5 and in the presence of an appropriate amount of the borate which forms α complex between one molecule of sugar and one molecle of boric acid.

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Many strains of yeast which can utilize n-alkanes as the sole source of carbon were isolated from flowers and fruits. Among them, a strain, OH23, identified as Candida tropicalis, formed acidic substances from n-alkanes. The principal products from n-alkanes with odd and even numbers of carbons were identified as glutaric and adipic acids, re-spectively. The culture conditions for their formation were investigated. n-Pentadecane and n-hexadecane were the best substrates for the formation of glutaric and adipic acids, respectively. Yields of 170mg of glutaric and 64mg of adipic acid were obtained from 100ml of media containing 4% (v/v) n-pentadecane and n-hexadecane, respectively, and 0.5% casamino acids.

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From the 2M urea extract of ground barley two zymogen β-amylase (Z-β-A) fractions (Fractions A and B) and one active β-amylase (A-β-A) fraction (Fraction C) were isolated by Sephadex G-75 gel filtration and purified by DEAE-Sephadex A-50 column chromato-graphy. The molecular weights of Fractions A, B and C were estimated to be approxi-mately 280000, 160000 and 56000, respectively. Both the Z-β-A fractions which were ultracentrifugally and electrophoretically homogeneous were found to be accompanied by a small amount of saccharogenic activities. From the estimation of Km values for these saccharogenic activities and the behavior in their activation with 2-mercaptoethanol and papain, it seems reasonable to conclude that Fraction A is a heteropolymer type of Z-β-A composed of both A-β-A and barley reserve proteins; that Fraction B is a homopolymer type of Z-β-A composed of A-β-A alone; and that two different activation mechanisms, proteolytic activation and disulfide bond cleaving activation, are necessary for full activation of Z-β-A in barley.

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Total β-amylase (T-β-A) activities in barley and malt were determined by the conventional method with papain and by the newly proposed method with 2-mercaptoethanol containing papain. Comparison between the activities determined by both methods during germination of barley made it clear that the new method was of propriety to determine the true T-β-A activity in barley or malt and that the conventional method was still useful for a prediction of salt-soluble active β-amylase (A-β-A) activity in malting barley after germination.
Though the amount of A-β-A in malt produced by normal germination did not reach to that of T-β-A determined by the new method, the gibberellic acid treatment of barley was found to enhance the activation of zymogen β-amylase (Z-β-A) in vivo which resulted in the increase in the papain-soluble A-β-A activity up to that of T-β-A. From these results it is quite possible that all the types of Z-β-A are activated by devices on malting method and that the increase in A-β-A activity during germination is exclusively due to the activation of Z-β-A formed during ripening and dormancy of barley.

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The milk-clotting activity of Mucor-rennin (Milk clotting enzyme of Mucor pusillus Lindt) was inhibited by reaction of diazo-l-H-tetrazole accompanied with increase of the value of the absorbance of biazo.histidine at 480 nm. The activity did not remain when the absorbance reached 50% of maximum value. It is concluded from these results that one mole of histidine in 2 moles of histidine contained in the enzyme has a relation to active center.

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During the investigation of petrochemical-utilizing microorganisms, a strain PGB-400-2 was found to produce a exocellular polysaccharide from 1, 2-propanediol.
From the results of taxonomical studies, the stain PGB-400-2 was determined to be Corynebacterium species.
The purified polysaccharide was homogeneous and its main components were rhamnose, mannose, glucose and galactose.

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A crystalline alkaline protease was prepared from Bacillus No. 221 isolated from soil. The characteristic point of this microorganism is especially good growth in alkaline media. The enzyme was most active at pH 11.5_??_12 towards casein and was stable at pH values from 4 to 11 on 10min incubation at 60°C. Calcium ion was effective to stabilize the enzyme especially at higher temperatures. The enzyme was completely inactivated by DFP and urea, but not affected by sulfhydryl reagent, EDTA, SLS, and DBS. The specific activity of the enzyme towards casein was about 18000 unit/mg, and the isoelectric point was higher than pH 9.4. The molecular weight and sedimentation constant was approximately 30000 and 3.5S respectively, and N-terminal of the enzyme was identified to be alanine. The results indicate that the No. 221 alkaline protease is different from those of alkaline Droteases of Bacillus subtilis.

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New biologically active substances named cotylenins Aand Bwere isolated from the culture filtrate of a fungus, strain 501-7w. Isolation and characterization are described in detail. The chemical relationship between the cotylenins has been elucidated.

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The heterogeneity of the proteolytic enzymes in the stem bromelain was investigated by the isoelectric focusing with carrier ampholytes. The isoelectric focusing of the stem bromelain demonstrated the presence of two types of proteolytic enzymes which were dis-tinguishable from each other by their isoelectric points. One of these was a basic protein having an isoelectric point of 9.45. This basic enzyme comprised almost all of basic pro-tein which are found in stem bromelain. The other was an acidic protein having an isoelectric point near pH 4.7. This was a minor compooent. The purification of the two enzymes was carried out by use of chromatographics on Chi-Sephadex, DEAE-Sephadex and Sephadex at pH 7.0.

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The present paper describes, together with its isolation procedures, the chemical structure determined for an unknown blue-violet fluorescent compound present in spinach. The effective isolation procedures consisted of methanol extraction from 30kg of spinach leaves, column chromatographies on cellulose powder and DEAE-cellulose, and gel filtration through Sephadex columns. The compound was obtained as colorless powder in the yield of 70mg. It was identified as 2-acetyl-3-(p-coumaroyl)-meso-tartaric acid basing on the spectral data and the experimental results of alkaline hydrolysis and chemical synthesis.

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A deoxyribonuclease was purified about 500 times from a Rhizopus product “Gluczyme.” The enzyme attacks native DNA and produces oligonucleotides terminated with pG, pA, or pG at the 5' end and with G at the 3' end. A small amount of mononucleotides was found in the digestion products when the hydrolysis was continued for a long period. The pH and temperature optima for the action were found to be 7.8_??_8.0 and 50°C, respectively, and the enzyme was activated three fold in the presence of 5×10^-3 M Mg²⁺ or Mn²⁺. This enzyme was named DNase Rh.

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The effect of concentration of each substrate in the reaction catalyzed by sucrose syn-thetase isolated from sweet potato roots was determined. For the sucrose synthesizing reaction, UDP-glucose(ADP-glucose)+fructose→sucrose+UDP(ADP), the substrate saturation curves for UDP-glucose, ADP-glucose and fructose were hyperbolic in shape and the reac-tion was strongly inhibited by UDP competitively. On the other hand, the substrates for the reversal of sucrose synthetase reaction, sucrose+UDP(ADP)→UDP-glucose(ADP-glucose)+fructose, exhibited a sigmoidal shaped saturation curve which was deviated from the Michaelis-Menten equation. The plot of data according to the empirical Hill equation gives_??_values greater than 1.0 for every substrate examined in the latter case. In view of these experimental data, the major role of sucrose synthetase is postulated in that this enzyme is involved in the breakdown of sucrose in sweet potato root tissues instead of the sucrose synthesizing reaction. The molecular weight of the enzyme was determined to be about 540000 by the Sephadex gel filtration chromatography.

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Radioresistance of the spores of 46 strains of Bacillus was determined based on their dose-survival curves. The spores were produced on three kinds of sporulating medium.
The variations in the radioresistance among species and strains were found, and also the radioresistance of spores depended upon the sporulating medium. The shapes of dose-survival curves are closely associated with the taxonomical groups of the genus Bacillus.
Radioresistance of the spores showed no apparent correlation to their contents of di-picolinic acid, calcium and magnesium, but a slight correlation was observed between radioresistance and the molar ratio of Ca to DPA or Mg to Ca. Radioresistance of the spores in some groups correlated to their GC content, but no correlation was found in the other species. There was no correlation between heat resistance and radioresistance.

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