The Formation of Glucose 1,6-Diphosphate from Fructose 1,6-Diphosphate by Yeast Phosphoglucomutase

It was found that fructose 1,6-diphosphate, the main intermediate of glycolysis, was able to act as a coenzyme of yeast phosphoglucomutase reaction. The mechanism of the coenzymatic activity of fructose 1,6-diphosphate was studied. It was indicated in the fructose 1,6-diphosphate dependent reaction that glucose 1,6-diphosphate was formed by the phosphate-transfer of fructose 1,6-diphosphate to glucose 1-phosphate in the first step, and in the second step the conversion of glucose 1-phosphate to glucose 6-phosphate, the original mutase reaction, occurred in the presence of glucose 1,6-diphosphate. The kinetic constants in the reaction of the first step were determined from the time courses of the fructose 1,6-diphosphate dependent reaction.     

Isolation and Identification of Native Auxins in Marine Algae

Endosperm cell walls were isolated from rice grains and their chemical composition was analyzed. The cell walls were composed of cellulose microfibrils and matrix phase which consisted of hemicellulose and pectic substances. Hemicellulose mainly comprised arabinoxylan, accompanied by a small amount of glucose-containing polysaccharide. Pectic substances contained polygalacturonides, some of which had side chains containing neutral sugars such as galactose and arabinose. Amino acid analysis of these fractions suggested that hydroxyproline-containing glycoproteins were contained in these cell walls and firmly bound to cellulose microfibrils.     

2-Nitropropane Dioxygenase from Hansenula mrakii: Re-characterization of the Enzyme and Oxidation of Anionic Nitroalkanes

2-Nitropropane dioxygenase, purified to homogeneity by an improved method from a yeast, Hansenula mrakii, has a molecular weight of 42,000, and consists of a single polypeptide. The enzyme contains 1 mol of FAD per mol of enzyme. The iron protein associated with previous preparations was removed by the present purification procedures. The enzyme catalyzes the oxygenative denitrification of anionic nitroalkanes much more effectively than that of the neutral ones with the optimum pH of 6.5. The Michaelis constants for the anionic substrates are as follows: 2-nitropropane, 1.61 mM; 1-nitropropane, 3.23 mM; nitroethane, 3.13 mM, and 3-nitro-2-butanol, 0.59 mM.     

Post-translational Modification of κ-Casein in the Golgi Apparatus of Mid-lactating Mammary Glands from Rat and Cow

Bovine κ-casein, a phosphoglycoprotein, has mucin-type carbohydrate chains. Subcellular distribution of enzymes that take part in the post-translational modification of κ-casein was examined. In lactating mammary glands from rats and cows, N-acetyl-galactosaminyl transferase, galactosyl transferase, sialyl transferase, and casein kinase were localized specifically in the Golgi apparatus.

The substrate specificities indicate that these enzymes are actually responsible for the processing of κ-casein.

The presence of a phosphate group attached to κ-casein did not affect the rate of glycosylation by N-acetyl-galactosaminyl transferase, while the presence of carbohydrate chains attached to κ- casein strongly reduced the rate of phosphorylation by casein kinase. These results suggest that in the Golgi apparatus, phosphorylation of κ-casein precedes glycosylation.     

A Phytotoxin,Betaenone C,and Its Related Metabolites of Phoma betae Fr

For rough quantitative analysis of genetically modified maize contents, rapid methods for measurement of the copy numbers of the cauliflower mosaic virus 35S promoter region (P35S) and MON810 construct-specific gene (MON810) using a combination of a capillary-type real-time PCR system with a plasmid DNA were established. To reduce the characteristic differences between the plasmid DNA and genomic DNA, we showed that pretreatment of the extracted genomic DNA by a combination of sonication and restriction endonuclease digestion before measurement is effective. The accuracy and reproducibility of this method for MON810 content (%) at a level of 5.0% MON810 mixed samples were within a range from 4.26 to 5.11% in the P35S copy number quantification. These methods should prove to be a useful tool to roughly quantify GM maize content.     

Action of α-Amylases on Oligosaccharides Terminated at the Reducing End by Sucrose

Oligosaccharides terminated by radioactive sucrose at the reducing end of maltooligosaccharides have been used in the oligosaccharide mapping procedure for characterizing α-amylases. The action patterns of ten α-amylases from various origins were investigated with this mapping method and compared with the results with normal maltooligosaccharides. The experimental results indicated that Bacillus subtilis saccharifying, Endomycopsis and pancreatic α-amylases had similar action patterns toward oligosaccharides with or without fructose at the reducing end. However, the action patterns of other seven α-amylases were somewhat different.     

Relative Cytokinin Activity of 3-Methyl Substituted Adenylate Cytokinins

More than 100 multi-component lures consisting of primary straight chain alkenols, their acetates and alkenals were prepared and tested as attractants of male lepidopterous insects. In field trials, male moths of 52 species were specifically attracted to two- or three-component lures. Further 35 lepidopterous species were found to be attracted to single component lures used as control. The main families captured by the multi-component lures were Tortricidae (24 species), Noctuidae (11 species) and Acrolepiidae (3 species). This successful attraction of so many species indicates the usefulness of systematic field tests using multi-component lures of selected synthetic chemicals.     

Effect of 1-Anilino-8-naphthalenesulfonate on Properties and Associations of αs-, β- and κ-Caseins

It was indicated from fluorescence spectra and fluorescence titration that a hydrophobic probe, 1-anilino-8-naphthalenesulfonate (ANS), binds to casein components (α_s-, β- and κ-caseins). Fluorescence intensity and affinity of ANS-κ-casein complex were larger than that of ANS-α_s- and ANS-β-casein complexes. Enhancements of fluorescence intensity of complexes of casein components were observed by the addition of KCI or CaCl₂. Reason for the enhancement was postulated to be the increase of the quantum yield of the ANS fluorescence caused by the environmental change of ANS binding region of the casein components.

Marked increase of sedimentation coefficient of β-casein in the presence of KCl or CaCl₂ at 10°C was caused by the addition of ANS. This may be responsible for the stimulation of the Ca-dependent precipitation of β-casein by the addition of ANS.

It was found that α_s · κ-association was prevented by ANS and that hydrophobic interaction have an important role for α_s · κ-association.     

Formation of Nicotinamide Ribose Diphosphate Ribose,a New Metabolite of NAD,by Aspergillus niger

Aspergillus niger (AKU 3302) degraded NAD to form Compound X. This compound was identified as nicotinamide ribose diphosphate ribose (NAmRDPR) by hydrolysis with alkaline or phosphodiesterase followed by chemical analysis of the products. NAmRDPR showed absorption maxima at 265~266 nm in 0.1 n HCI and 325 nm in 1.0 n KCN. Optimal pH for NAmRDPR formation by the enzyme preparation from this organism was around 4.0. Formation of NAmRDPR proceeded stoichiometrically with degradation of NAD. Some of other strains of A. niger formed NAmRDPR, but production of this compound was not demonstrated in other mold genera.