The Gene Encoding Flavanone 3-Hydroxylase is Expressed Normally in the Pale Yellow Flowers of the Japanese Morning Glory Carrying the speckled Mutation Which Produce Neither Flavonol nor Anthocyanin but Accumulate Chalcone, Aurone and Flavanone

The Japanese morning glory carrying the recessive mutable speckledallele with the dominant speckled-activator bears colorlessflowers with fine and round colored spots distributed over thecorolla whereas the plant without the speckled-activator producespale yellow flowers. Previous chemical analysis has indicatedthat a mutation in the gene for flavanone 3-hydroxylase (F3H)is a likely candidate for the speckled allele. However, theF3HmRNA without sequence alteration accumulates normally inthe pale yellow flowers, indicating that the speckled alleleis neither the F3H gene nor a regulatory gene acting on theF3H gene expression. (Received April 4, 1997; Accepted June 2, 1997)     

Expression level of enzymes related to in situ estrogen synthesis and clinicopathological parameters in breast cancer patients

In order to evaluate the importance of estrogen production in tumor and surrounding tissues, we measured mRNA expression levels of 5 enzymes participating to estrogen synthesis in situ and 4 breast cancer-related proteins in 27 pairs of tumor and non-malignant tissues. Steroid sulfatase (STS) mRNA was more frequently detected in tumor tissues rather than in their non-malignant counterparts. Estrogen sulfotransferase (EST) was constantly expressed with high level not only in tumor tissues but also in their surrounding non-malignant counterparts. In contrast, mRNA expression levels of aromatase, and 17β-hydroxysteroid dehydrogenase type I and II were relatively low and detected only in small proportion of the patients. We also measured the mRNA expression levels of the same nine genes in tumor tissues of 197 breast cancer patients, and analyzed relationship between the mRNA expression level and the clinicopathological parameters. The mRNA expression levels of STS, aromatase and erbB2 in tumor tissues increased as breast cancer progressed. The tumoral mRNA expression levels of STS, estrogen receptor β, and erbB2 in patients with recurrence were higher than those in patients without recurrence. Upregulation of STS expression plays an important role in tumor progression of human breast cancer and is considered to be responsible for estrogen production in tumor and surrounding tissues.     

Isolation of lactoperoxidase, lactoferrin, α-lactalbumin, β-lactoglobulin B and β-lactoglobulin A from bovine rennet whey using ion exchange chromatography

A mild and rapid method is described for isolating various milk proteins from bovine rennet whey. β-Lactoglobulin from bovine rennet whey was easily adsorbed on and desorbed from a weak anion exchanger, diethylaminoethyl-Toyopearl. However, α-lactalbumin could not be adsorbed onto the resin. α-Lactalbumin and β-lactoglobulin from rennet whey could also be adsorbed and separated using a strong anion exchanger, quaternary aminoethyl-Toyopearl. The rennet whey was passed through a strong cation exchanger, sulphopropyl-Toyopearl, to separate lactoperoxidase and lactoferrin. α-Lactalbumin and β-lactoglobulin were adsorbed onto quaternary aminoethyl-Toyopearl. α-Lactalbumin was eluted using a linear (0–0.15 M) concentration gradient of NaCl in 0.05 M Tris–HCl buffer (pH 8.5). Subsequently, β-lactoglobulin B and β-lactoglobulin A were eluted from the column with 0.05 M Tris–HCl (pH 6.8), using a linear (0.1–0.25 M) concentration gradient of NaCl. The yields were 1260 mg α-lactalbumin, 1290 mg β-lactoglobulin B and 2280 mg β-lactoglobulin A from 1 l rennet whey.     

Adenosine binding sites of rat pheochromocytoma PC 12 cell membranes: partial characterization and solubilization

Rat pheochromocytoma PC 12 cell membranes were shown to possess A2-like adenosine binding sites as assessed by using 5'-N-ethylcarboxamide[3H]adenosine [( 3H]NECA). Specific [3H]NECA binding to PC 12 cell membrane at 0 degrees C was saturable and showed a monophasic saturation profile. In contrast, [3H]NECA binding to PC 12 cell membrane at 30 degrees C exhibited a biphasic profile suggesting the presence of two specific binding site. The rank order of potency for inhibition of [3H]NECA binding at 0 degrees C was NECA greater than 2-chloroadenosine greater than 2',5'-dideoxyadenosine greater than isobutylmethylxanthine much greater than phenylisopropyladenosine. These adenosine binding sites were solubilized with sodium cholate and the solubilized portion retained the same ligand binding characteristics as those of the membrane-bound form. Gel filtration experiments indicated an apparent Stokes radius of 6.7 nm for these adenosine binding sites/detergent complexes.     

Isolation and partial characterization of the major glycoproteins of horse and swine erythrocyte membranes

The major glycoproteins of horse and swine erythrocyte membranes were isolated and examined chemically and immunologically. The major glycoprotein of horse erythrocyte membranes had a molecular weight of 33 000 and consisted of 46.2% protein and 53.8% carbohydrate, of which 9.4% was hexose, 10.1% hexosamine and 33.7% sialic acid. This glycoprotein was associated with activity for the infectious mononucleosis heterophile antigen.There were two different major glycoproteins in swine erythrocyte membranes. One major glycoprotein had a molecular weight of 46 200 and consisted of 34.2% protein and 65.8% carbohydrate, of which 18% was hexose, 19% hexosamine and 27.2% sialic acid. This glycoprotein had phytohemagglutinin (Phaseolus vulgaris) binding activity. The other glycoprotein had a molecular weight of 29 000 and consisted of 50.4% protein and 49.6% carbohydrate, of which 6.4% was hexose, 7.0% hexosamine and 36.3% sialic acid. This glycoprotein had weak or absent phytohemagglutinin binding activity.     

Thermotropic phase behavior and stability of monosialoganglioside micelles in aqueous solution.

The thermotropic phase behavior of monosialoganglioside in a dilute aqueous dispersion at pH 6.8 was measured by using synchrotron radiation small-angle x-ray scattering and was analyzed by a shell-modeling method. Previous calorimetric studies on ganglioside systems have shown quite different thermotropic behaviors from other biological lipid systems, however, the details have still been ambiguous. Because of high statistical data and a shell-modeling analysis, we could elucidate the internal structural change of monosialoganglioside micelle induced by the elevation of temperature from 6 to 60 degrees C, that is, the shrinkage of the hydrophilic region and the slight expansion of the hydrophobic region occurring simultaneously, accompanying the elongation of the axial ratios of the ellipsoidal micelles. The model structures obtained explain the changes in the experimental scattering curves, the distance distribution functions, and the gyration radii. In addition we have also found an evident thermal hysteresis in the scattering curves and in the structural parameters. The present result suggests that the thickness of the hydrophilic region, namely, the conformation of oligosaccharide chains, is sensitive to a change of temperature.     

Methylation of c-myc gene changes in human lymphoproliferative diseases

The degree of methylation at the c-myc proto-oncogene was found to change in human lymphoproliferative diseases, when examined using a methylation-sensitive restriction enzyme. In peripheral blood mononuclear cells (PBMC) c-myc DNA showed hypomethylation in human lymphoproliferative diseases, in comparison to normal subjects matched in age and sex. In cases of chronic lymphocytic leukemia (CLL), the change was amplified in the crisis. When the DNA was examined at the actin gene, no significant change was observed. The results suggest that the change in c-myc proto-oncogene methylation might become an important clue in understanding the relationship between levels of gene expression and methylation in human lymphoproliferative diseases.     

Effect of Gibberellic Acid on the Ultrastructure and {alpha}-Amylase Activity of Aleurone Cells of Avena sativa L.

The -amylase activity and ultrastructure of aleurone cells inseeds of Avena sativa L. were studied using seed halves withembryo (embryo seeds) which had imbibed water and seed halveswithout embryo (embryo-less seeds) which had imbibed water withor without GA₃. -Amylase activity was detected in the aleurone layers of embryoseeds that had imbibed water and embryo-less seeds that hadimbibed GA₃-water. The ultrastructure of aleurone cells withdetectable -amylase activity showed marked changes in the roughsurfaced endoplasmic reticulum (rER), in the flattened sacculesforming stacks and in the aleurone grains. The progressive changesin the rER were as follows: first, the number of slender rERincreased; then, the inner space became wider and showed roundor oval profile; and finally, the rER became slender again witha reduced number of adhering ribosomes. The flattened sacculesforming stacks were appressed to the surface of aleurone grains.With time, they decreased in number and finally disappeared.In parallel with the decrease of flattened saccules, digestionof proteinaceous material inside the aleurone grains proceeded. (Received February 24, 1987; Accepted September 3, 1987)     

Analytical studies on the responses of sunflower (Helianthus annuus) to various defoliation treatments

The effects of defoliation treatments on plant growth in sunflower (Helianthus annuus) were studied in the field. Four defoliation treatments, 0 (control), 37.4, 56.1 and 93.4% of the total leaf dry weight, were applied to plants that had small third leaves. Decreased leaf weight/whole plant weight (F/W) ratios in defoliated plants rapidly recovered to almost the same ratio as that observed in the control within 12 to 16 days after defoliation according to the degree of defoliation. The mechanism involved in the recovery of the F/W ratio in defoliated plants mainly consisted of three parameters: enhancement of (1) carbon distribution ratios in the leaves, (2) photosynthetic activity in the remaining leaves, and (3) retranslocation of carbon from the stem and/or roots to leaves. Inhibitive effects of defoliation on relative growth rate and net assimilation rate were seen at an early stage, but subsequently both rates became larger in defoliated plants than in controls. Defoliated plants tended to show rapid development and expansion of new leaves, and to show increased specific leaf area and protein synthesis in individual leaves. The sugar content of leaves in defoliated plants was higher than that in controls, while the content in both stem and roots was lower. These responses seem to be advantageous for development of the photosynthetic system. Heights of defoliated plants were clearly depressed according to the degree of defoliation, and this was attributed largely to differences in the elongation rates of the internodes resulting from defoliation.