Molecular modeling of flavonoids that inhibits xanthine oxidase

The inhibition of xanthine oxidase activity by various flavonoids was assessed. All of the tested flavonoids were competitive inhibitors, and from the kinetic analysis suggested that flavonoids bind to the reactive site. To further understand the stereochemistry between these flavonoids and xanthine oxidase, structure-based molecular modeling was performed. Apigenin was the most potent inhibitor which showed the most favorable interaction in the reactive site. The bicyclic benzopyranone ring of apigenin stacked with phenyl of Phe 914, and the phenolic group stretched to the space surrounding with several hydrophobic residues. Quercetin and myricetin composed a 3-hydroxyl group on benzopyranone which resulting in reduction of binding affinity. The phenolic group of genistein positioned in opposite orientation comparison with apigenin, and resulted in a weaker interaction with xanthine oxidase. Isovitexin showed the weakest inhibitory effect among the compounds tested. The bulky group of sugar in isovitexin may hamper its interaction with xanthine oxidase.     

Resistin and RELM-alpha gene expression in white adipose tissue of lactating mice

An ORF2 gene located upstream of the cellulose synthase (bcs) operon of Acetobacter xylinum BPR2001 was disrupted and a mutant (M2-2) was constructed. In static cultivation, the parent strain produced a tough, colorless, and insoluble cellulose pellicle, whereas M2-2 culture produced a thin, yellow, and fragile pellicle. The results of X-ray diffraction and 13C solid-state NMR indicated that the product of M2-2 is a mixture of cellulose I, cellulose II, and amorphous cellulose. The cellulose I to cellulose II ratio of the mixture was evaluated from the signal areas of C6 to be about 1:2. Electron microscopy revealed that the product of M2-2 included ribbon-like cellulose and irregularly shaped particles attached to the ribbons. On the other hand, the mutant complemented with plasmid pSA-ORF2/k containing the ORF2 gene and BPR2001 produced only cellulose I. These results indicate that the ORF2 gene is involved in the production and crystallization of cellulose I microfibrils by this microorganism.     

Blazeispirane and protoblazeispirane derivatives from the cultured mycelia of the fungus Agaricus blazei

Two blazeispirane derivatives including blazeispirols G and I were isolated from the cultured mycelia of the fungus Agaricus blazei Murill and were established to be (20S, 22S, 23R, 24S)-14 beta,22: 22,25-diepoxy-5-methoxy-des-A-ergosta-5,7,9-triene-11 alpha,23-diol and (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-5-methoxy-des-A-ergosta-5,7,9,11-tetraene-23,28-diol by comparison of extensive 1D and 2D NMR spectral data with that of blazeispirol A. Furthermore, four blazeispirol derivatives blazeispirols, U, V, V(1) and Z(1) were isolated form the same source described above. Their structures were determined to be (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-23-hydroxyergosta-4,6,8,11-tetraen-3-one, (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-6 alpha,7 alpha,23-trihydroxyergosta-4,8,11-trien-3-one, (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-6 beta,7 alpha,23-trihydroxyergosta-4,8,11-trien-3-one and (20S, 22S, 23R, 24S)-14 beta,22:22,25-diepoxy-23-hydroxy-4,5-seco-ergosta-6,8-diene-3,5-dione by extensive 1 D and 2D NMR spectral data.     

Enhancement of the protective efficacy of an oprF DNA vaccine against Pseudomonas aeruginosa

The outer membrane protein F gene (oprF) of Pseudomonas aeruginosa was recently shown by us to protect mice from P. aeruginosa chronic pulmonary infection when used as a DNA vaccine administered by three biolistic (gene gun) intradermal inoculations given at 2-week intervals. In the present study, we used two different strategies to improve the protective efficacy of the DNA vaccine. In the first strategy, mice were primed with two biolistic intradermal inoculations with the oprF vaccine and then were given a final intramuscular booster immunization containing either a synthetic peptide-keyhole limpet hemocyanin (KLH) conjugate or a chimeric influenza virus. Both the synthetic peptide conjugate and the chimeric virus contained peptide 10, a previously identified immunoprotective epitope of protein F. The second strategy involved the addition of a second outer membrane protein to the vaccine. DNA encoding a fusion protein comprised of the C-terminal half of protein F fused to OprI was administered by three biolistic intradermal inoculations. Challenge with P. aeruginosa in a chronic pulmonary infection model demonstrated that boosting with the chimeric virus (but not with peptide-KLH) or adding oprI to the DNA vaccine significantly enhanced protection as compared to that afforded by the oprF vaccine given alone. Thus, both strategies appear to augment the protection afforded by an oprF-only DNA vaccine.     

Endometriosis: the pathophysiology as an estrogen-dependent disease

Endometriosis, defined as the presence of endometrial glands and stroma outside of the uterine cavity, develops mostly in women of reproductive age and regresses after menopause or ovariectomy, suggesting that the growth is estrogen-dependent. Indeed, the lesions contain estrogen receptors (ER) as well as aromatase, an enzyme that catalyses the conversion of androgens to estrogens, suggesting that local estrogen production may stimulate the growth of lesions. The expression patterns of ER and progesterone receptors in endometriotic lesions are different from those in the eutopic endometrium. Moreover, estrogen metabolism, including the expression pattern of aromatase and the regulation of 17β-hydroxysteroid dehydrogenase type 2 (an enzyme responsible for the inactivation of estradiol to estrone), is altered in the eutopic endometrium of women with endometriosis, adenomyosis, and/or leiomyomas compared to that in the eutopic endometrium of women without disease. Immunostaining for P450arom in endometrial biopsy specimens diagnosed these diseases with sensitivity and specificity of 91 and 100%, respectively. This is applicable to the clinical diagnosis of endometriosis. The polymorphisms in the ER- gene, the CYP19 gene encoding aromatase, and several other genes are associated with the risk of endometriosis. Studies of these will lead to better understandings of the etiology and pathophysiology of endometriosis.     

The absence of molybdenum cofactor sulfuration is the primary cause of the flacca phenotype in tomato plants

The molybdenum cofactor (MoCo)-containing enzymes aldehyde oxidase (AO; EC 1.2.3.1) and xanthine dehydrogenase (XDH; EC 1.2.1.37) require for activity a sulfuration step that inserts a terminal sulfur ligand into the MoCo. The tomato flacca mutation was originally isolated as a wilty phenotype due to a lack of abscisic acid (ABA) that is related to simultaneous loss of AO and XDH activities. An expressed sequence tag candidate from tomato was selected on the basis of homology to sulfurases from animals, fungi and the recently isolated Arabidopsis genes LOS5/ABA3. The tomato homologue maps as a single gene to the bottom of chromosome 7, consistent with the genetic location of the flacca mutation. The structure of FLACCA shows a multidomain protein with an N-terminal NifS-like sulfurase domain; a mammal-specific intermediate section; and a C-terminus containing conserved motifs. Prominent among these are molybdopterin oxidoreductases and thioredoxin redox-active centre/iron-sulfur-binding region signatures which may be relevant to the specific sulfuration of MoCo. Indeed, the molecular analysis of flacca identifies the mutation in a highly conserved motif located in the C-terminus. Activity gel assays show that FLACCA is expressed throughout the plant. Transient and stable complementation of flacca and the Arabidopsis aba3 mutants with Aspergillus nidulans hxB and FLACCA yielded full, partial and tissue-specific types of Mo-hydroxylase activities. Restoration of activity in the root alone is sufficient to augment plant ABA content and rectify the wild-type phenotype. Thus the pleiotropic flacca phenotype is due to the loss of activity of enzymes requiring a sulfurated MoCo.