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E Okuyama

Publications and source records attributed to E Okuyama.

At least 37 records · Page 2Linked to original sources
PubMed1997

Molecular cloning of sheep and goat ferredoxin reductase messenger ribonucleic acids, and identification of an alternatively spliced form of sheep ferredoxin reductase.

Complementary DNA clones of mRNAs for sheep and goat NADPH-ferredoxin reductases (ferredoxin NADP+ oxidoreductase, EC 1.18.1.2) were isolated by the reverse transcriptase polymerase chain reaction method, and the complete nucleotide sequences of the coding and 3'-flanking regions of these cDNA clones were determined. Comparative analysis using the deduced amino acid sequences of NADPH-ferredoxin reductases clarified the interspecific conservation of the ferredoxin-binding and flavin adenine dinucleotide (FAD)-binding regions, confirming the results reported previously. During this study, we happened to identify an alternatively spliced mRNA that completely lacks exon 3, just adjacent to the FAD-binding region of the sheep NADPH-ferredoxin reductase cDNA clone. In the screening of other alternatively spliced mRNAs of NADPH-ferredoxin reductases derived from several steroidogenic organs, such as adrenocortices, testes, and ovaries of sheep and goats, only one kind of alternatively spliced mRNA as described above was detected in sheep adrenocortices. Then, we constructed Escherichia coli expression systems for these two forms of mRNA and analyzed their enzymatic properties. We found that the ability of the alternatively spliced NADPH-ferredoxin reductase protein to transfer electrons to ferredoxin is completely abolished because FAD binding is inhibited.

Alternative Splicing↗
PubMed1997

No linkage of the cytochrome P-450IIE1 (CYP2E1) C1/C2 polymorphism to schizophrenia.

We investigated, using PCR-SSCP analysis, the relationship between schizophrenia and the polymorphism of d-benzphetamine N-demethylase (cytochrome P-450j or CYP2E1), which metabolizes psychotropic substances such as d-benzphetamine and alcohols. Among 41 patients with schizophrenia, no statistically significant change in the frequency of the mutant (C2) allele relative to in controls was found, and no novel structural mutation in the CYP2E1 gene, which would be expected to alter the CYP2E1 protein, was found. This could be explained by no linkage of the CYP2E1 gene (mutations in the exon 1-9, and C1/C2 polymorphism) to schizophrenia.

Adult↗
PubMed1997

A novel splicing junction mutation in the gene for the steroidogenic acute regulatory protein causes congenital lipoid adrenal hyperplasia.

Congenital lipoid adrenal hyperplasia (lipoid CAH) is a relatively common genetic disorder of adrenal and gonadal steroidogenesis and is the most severe form of CAH. As typical affected individuals cannot produce any steroid hormones or can only produce low levels of steroid hormones in the adrenals and gonads, including glucocorticoids, mineralcorticoids, and sex steroids, a genetic defect in the cholesterol side-chain cleavage enzyme, cytochrome P450scc (CYPXIA1), has been postulated to be the cause of their insufficient production to date. Recently, Lin and co-workers proved a link between mutations of the steroidogenic acute regulatory protein (StAR) gene and the lipoid CAH phenotype. Therefore, we investigated both the cytochrome P450scc and StAR genes in a Korean family with a fairly mild form of lipoid CAH to identify the mutation(s) causing this disease. The result was that no mutations could be found in the two genes, except for a thymine (T) insertion into intron 2 of the StAR gene, 3 bp from the splice donor site of exon 2. PCR-amplified StAR genes from a normal subject and the patient were cloned into an expression vector and then introduced into COS-7 cells. Northern blot and reverse transcriptase-PCR analyses indicated that the StAR messenger ribonucleic acid derived from the vector with the normal StAR gene spliced exons 2 and 3 correctly, whereas most, but not all, StAR messenger ribonucleic acid derived from the vector with the T-inserted StAR gene could not remove intron 2. We concluded from these results that the T insertion into the StAR gene accounts for the lipoid CAH phenotype in this patient.

Adrenal Hyperplasia, Congenital↗
PubMed1996

Characteristic properties of a retinoic acid synthetic cytochrome P-450 purified from liver microsomes of 3-methylcholanthrene-induced rats.

An inducible cytochrome P-450 (P-450) catalyzing retinoic acid synthesis was purified from liver microsomes of 3-methylcholanthrene (3-MC)-treated rats, based on the activity of all-trans-retinoic acid formation from all-trans-retinal. We previously reported that the retinoic acid synthesis by microsomes was catalyzed by a cytochrome P-450-linked monooxygenase system (Tomita et al. (1993) Int. J. Biochem. 25, 1775-1784). This microsomal retinoic acid synthesis in rat liver was induced more than 8-fold by 3-MC. The purified P-450 electophoretically gave a single protein band and its minimum molecular weight was estimated to be 57.2 kDa on SDS-PAGE. The optical spectrum of the oxidized P-450 without retinal revealed it was the low-spin form, and the CO-complex exhibited a maximum peak at 447 nm. The specific activity of the reconstituted P-450-linked monooxygenase system was 29.5 nmol/min per nmol P-450 at pH 7.6 and 37 degrees C. The K(m) and Vmax values for all-trans-retinal were 11.6 microM and 38.5 nmol/min per nmol P-450, respectively. The amino-acid sequence of the N-terminal region of the P-450 was identical to that of rat P-450 1A1 (CYP 1A1). Xenobiotic activities, such as 7-ethoxycoumarin O-deethylase (7-ECOD) and 7-ethoxyresorufin O-deethylase (7-EROD) activities, of the P-450-linked monooxygenase system were specific to the P-450 1A1. The retinoic acid formation in the reconstituted monooxygenase system was specifically inhibited by alpha-naphthoflavone (alpha-NF), which is a P-450 1A1-specific inhibitor, citral, which is a retinoid analogue structurally, and an anti-rat P-450 1A1 antibody. These results further support that the purified P-450 is P-450 1A1. This paper describes that P-450 1A1 was purified and characterized as a retinoic acid synthetic P-450.

Acyclic Monoterpenes↗
PubMed1996

Genetic analysis of the cytochrome P-45OIIC18 (CYP2C18) gene and a novel member of the CYP2C subfamily.

The CYP2C18 gene was investigated in order to characterize its molecular basis in the CYP2C subfamily. A mutation of the CYP2C18 gene was identified at the 5'-flanking region of the gene, which could be detected by digestion with DdeI. The allele frequency of the mutant CYP2C18 gene was 21.4%. Genotypes of the polymorphic DdeI site of the CYP2C18 gene were found to be completely consistent with that of the polymorphic CYP2C19 gene (the m1 mutant). The CYP2C18 and CYP2C19 genes were suggested to be linked and located close together on the chromosome. Clones containing the 5'-flanking region of a member of the CYP2C subfamily were obtained from the PCR products from human genomic DNA. The nucleotide sequence of the clone proved to be 90.5% identical to the corresponding region of the CYP2C18 gene. This is very likely to be a novel member of the CYP2C subfamily.

Alleles↗
PubMed1996

Molecular cloning and nucleotide sequences of cDNA clones of sheep and goat adrenocortical cytochromes P450scc (CYP11A1).

We isolated cDNA clones of the mRNAs for cytochromes P450scc (CYP11A1) from sheep and goat adrenocortices using the RT-PCR method. We determined the complete nucleotide sequences of the coding and 3'-flanking regions of these cDNA clones. The results confirmed the amino terminal sequence of the sheep cytochrome P450scc reported previously [Miyatake et al., Biochim. Biophys. Acta 1215,176-182 (1994)]. On the basis of comparison of the deduced amino acid sequences of various animals and rainbow trout cytochromes P450scc, and other mitochondrial cytochrome P450 isozymes, we discussed the substrate-associated and adreno-ferredoxin-binding region of cytochrome P450scc.

Adrenal Cortex↗
PubMed1996

Molecular evolution of the 5'-flanking regions of the duplicated Amy genes in Drosophila melanogaster species subgroup.

The nucleotide sequences of the 5'-flanking regions of the duplicated Amy genes in eight sibling species belonging to the melanogaster species subgroup are analyzed. In Drosophila melanogaster, a region of about 450 bp immediately upstream of the translation initiation site of the two paralogous genes (the proximal and distal genes) has sequence similarities. However, we could not detect any significant sequence similarity in the region more upstream than -450. This result indicates that the coding regions of the ancestral Amy gene were duplicated together with 450 bp of the 5'-flanking region as one unit. Multiple alignment of these 450-bp sequences in the proximal and distal genes of all eight species revealed a mosaic pattern of highly conserved and divergent regions. The conserved regions included almost all the putative regulatory elements identified in previous analyses of the sequences. A phylogenetic analysis of the aligned sequences shows that these 450-bp sequences are clustered into the proximal and the distal groups. As a whole, the divergence between groups in this region is very large in contrast to that in the coding regions. Based on the divergence between groups, the 450-bp region is divided into two subregions. We found that the ratios of the divergence between groups to that within groups differ in the two subregions. From these observations, we discuss a possibility of positive selection acting on the subregion immediately upstream of the Amy coding region to cause divergence of regulatory elements of the paralogous genes.

Animals↗
PubMed1996

A new series of coumarin derivatives having monoamine oxidase inhibitory activity from Monascus anka.

Monankarins A-F (1-6), a new series of pigments having conjugated pyrano-coumarin skeleton have been isolated from Monascus anka. Their structures have been elucidated by spectroscopic means and chemical modification. Monankarins A-D exhibited monoamine oxidase (MAO) inhibitory activity, while the activity was not observed in monankarins E and F or some other simple coumarins. Monankarin C (3) showed stronger inhibition of MAO-B than MAO-A in mice brain. However, the specificity was not found in mice liver MAO.

Animals↗
PubMed1996

Neurotropic components from star anise (Illicium verum Hook. fil.)

Three new neurotropic sesquiterpenoids, veranisatins A, B and C, were isolated from star anise (Illicium verum Hook. fil., Illiciaceae). Veranisatins showed convulsion and lethal toxicity in mice at a dose of 3 mg/kg (p.o.), and at lower doses they caused hypothermia. Veranisatin A and the related compound, anisatin, were tested for the other pharmacological activities such as locomotor activity and analgesic effect. Both compounds decreased the locomotion enhanced by methamphetamine at oral doses of 0.1 and 0.03 mg/kg, respectively, and demonstrated the analgesia on acetic acid-induced writhing and tail pressure pain at almost similar doses.

Acetic Acid↗
PubMed1996

Pharmacologically active components of a Peruvian medicinal plant, huanarpo (Jatropha cilliata).

From Jatropha cilliata M. Arg., a Peruvian medicinal plant, isoorientin and orientin were isolated as anxiolytic components by using the isolation guide of anti-conflict effect in mice. Several related flavonoids were also tested for this effect. Another bioassay-guided isolation using the acetic acid-induced writhing method gave a coumarin compound, fraxetin, as an analgesic principle.

Analgesics↗
PubMed1996

A novel mutation in the cytochrome P450(27) (CYP27) gene caused cerebrotendinous xanthomatosis in a Japanese family.

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disease caused by mutations in the cytochrome P450(27) (CYP27) gene. This disease is characterized by the accumulation of a bile alcohol, cholestanol, in diverse tissues. Accumulation in the central nervous system leads to neurological dysfunction including dementia, spinal cord paresis, and cerebellar ataxia. Accumulation in other tissues causes tendon xanthomas, premature atherosclerosis, and cataracts. In a Japanese family with CTX, we identified two points mutations in the CYP27 gene at different sites. One is a novel transversion, which substitutes G for C at Pro 368 (CCC) to Arg (CGC). The other is a transition, which substitutes A for G at Arg441 (CGG) to Gln (CAG), this being the same mutation that Kim et al. reported (1994. J. Lipid Res. 35: 1031 - 1039). Allele-specific polymerase chain reaction analysis indicated that the father and mother of this family, who themselves had no clinical manifestations of CTX, had the former and latter mutations heterozygously, respectively. On the other hand, the patients each had both mutations heterozygously. These results are highly suggestive, but not conclusive, that the newly identified transversion in the CYP27 gene accounts for the sterol 27-hydroxylase (EC 1.14.13.15) deficiency in these patients.

Alleles↗
PubMed1995

Usnic acid and diffractaic acid as analgesic and antipyretic components of Usnea diffracta.

Diffractaic acid and usnic acid were identified as the analgesic and antipyretic components of a lichen, Usnea diffracta. Both compounds showed an analgesic effect by the acetic acid-induced writhing and tail-pressure methods in mice. Regarding the effect on normal body temperature and LPS-induced hyperthermia in mice, diffractaic acid showed a significant effect only on the former and usnic acid only on the latter.

Analgesics↗
PubMed1995

Evolutionary relationships and sequence variation of alpha-amylase variants encoded by duplicated genes in the Amy locus of Drosophila melanogaster.

To infer the genealogical relationships of alpha-amylase electromorphs of Drosophila melanogaster, we determined the nucleotide sequences of a collection of electromorphs sampled throughout the world. On average there were 1.0 amino acid substitutions between identical electromorphs and 3.9 between different electromorphs, respectively. We found that the evolution of AMY1 through AMY6 electromorphs occurred by sequential accumulation of single amino acid substitutions each causing one charge difference. The nucleotide diversities at synonymous sites within Amy1,Amy2,Amy3,Amy4 and Amy6 were 0.0321, 0.0000, 0.0355, 0.0059 and 0.0030, respectively. We also obtained evidence of genetic exchanges, such as intrachromosomal recombination, interchromosomal recombination or gene conversion, between the two duplicated Amy genes as well as among the alleles.

Amino Acid Sequence↗
PubMed1995

Pharmacologically active components of Todopon Puok (Fagraea racemosa), a medicinal plant from Borneo.

The lignans of (+)-pinoresinol, (+)-epipinoresinol, (+)-lariciresinol and (+)-isolariciresinol together with phenols such as syringaldehyde and 7,8-dihydro-7-oxy-coniferyl alcohol were isolated from Todopon Puok (Fagraea racemosa Jack ex Wall), a medicinal plant from Borneo, using a bioassay of the relaxation effect on norepinephrine (NE)-induced contraction in rat aortic strips. The plant extract also exhibited analgesic properties in the acetic acid-induced writhing and tail pressure tests in mice, with the activity being concentrated in the lignan fraction. (+)-Pinoresinol showed analgesic effect on writhing symptoms in mice which were dose-dependent, and produced local anesthesia in guinea pigs.

Analgesics↗
PubMed1994

Pharmacologically active components from a Peruvian medicinal plant, huira-huira (Culcitium canescens H. & B.).

The methanol extract of Huira-Huira (Culcitium canescens) showed analgesic effects in acetic acid-induced writhing and tail pressure tests, and it also produced potent prolongation of hypnosis induced by pentobarbital. The latter activity was used as an isolation-guide to determine the active components which were identified as dehydrocacalohastine, cacalohastine and cacalonol.

Analgesics↗
PubMed1993

Ascaridole as a pharmacologically active principle of "Paico," a medicinal Peruvian plant.

"Paico," Chenopodium ambrosioides L., is a traditional Peruvian medicine which is considered to be nervine, antirheumatic, anthelmintic, etc. An attempt was made to isolate the component having sedative and/or analgesic properties from "Paico" and "Aritasou" (the Japanese name for C. ambrosioides). Ascaridole was identified as the active principle in both materials.

Analgesics↗