Core alpha1,3-fucose is a key part of the epitope recognized by antibodies reacting against plant N-linked oligosaccharides and is present in a wide variety of plant extracts

Carbohydrates have been suggested to account for some IgE cross- reactions between various plant, insect, and mollusk extracts, while some IgG antibodies have been successfully raised against plant glycoproteins. A rat monoclonal antibody raised against elderberry abscission tissue (YZ1/2.23) and rabbit polyclonal antiserum against horseradish peroxidase were screened for reactivity in enzyme-linked immunosorbent assay against a range of plant glycoproteins and extracts as well as neoglycoproteins, bee venom phospholipase, and several animal glycoproteins. Of the oligosaccharides tested, Man3XylFucGlcNAc2(MMXF3) derived from horseradish peroxidase was the most potent inhibitor of the reactivity of both YZ1/2.23 and anti- horseradish peroxidase to native horseradish peroxidase glycoprotein. The reactivity of YZ1/2. 23 and anti-horseradish peroxidase against Sophora japonica lectin was most inhibited by a neoglycoconjugate of bromelain glycopeptide cross-linked to bovine serum albumin, while the defucosylated form of this conjugate was inactive as an inhibitor. A wide range of plant extracts was found to react against YZ1/2.23 and anti-horseradish peroxidase, with particularly high reactivities recorded for grass pollen and nut extracts. All these reactivities were inhibitable with the bromelain glycopeptide/bovine serum albumin conjugate. Bee venom phospholipase and whole bee venom reacted weakly with YZ1/2.23 but more strongly with anti-horseradish peroxidase in a manner inhibitable with the bromelain glycopeptide/bovine serum albumin conjugate, while hemocyanin from Helix pomatia reacted poorly with YZ1/2.23 but did react with anti-horseradish peroxidase. It is concluded that the alpha1, 3-fucose residue linked to the chitobiose core of plant glycoproteins is the most important residue in the epitope recognized by the two antibodies studied, but that the polyclonal anti-horseradish peroxidase antiserum also contains antibody populations that recognize the xylose linked to the core mannose of many plant and gastropod N-linked oligosaccharides.      

Induction of cytochrome P-450 forms by prolonged administration of nifedipine

In experiments on male Wistar rats it has been found that nifedipine applied in a dose of 10 mg/kg body weight i.p. daily for 20 days did not significantly increase the total amount of cytochrome P-450 but markedly increased the 7 alpha-, 16 beta- and 6 beta-hydroxylation of androstenedione in liver microsomes, suggesting the induction of cytochromes P-450a, P-450b and P-450p respectively. The induction of cytochrome P-450b was also confirmed immunochemically with polyclonal antibodies against cytochrome P-450b/e.     

A new practical tool for deriving a functional signature for herbaceous vegetation

Hypothesis: For any one time and place a ‘functional signature’ can be derived for a sample of herbaceous vegetation in a way that concisely represents the balance between the different clusters of functional attributes that are present among component species. Methods: We developed a spreadsheet‐based tool for calculating functional signatures within the context of the C‐S‐R system of plant functional types. We used the tool to calculate and compare signatures for specimen British vegetation samples which differed in management regime and location in time. Conclusion: The integrative power of the ‘C‐S‐R signature’ is useful in comparative studies involving widely differing samples. Movements in the signature can be used to indicate degree of resistance, resilience, eutrophication and dereliction. Systems of plant functional types other than C‐S‐R might also be approached in this way. Availability: The tool can be downloaded free of charge from the first author's web pages or from the journal's electronic archive.     

Mitochondria-targeted plastoquinone derivatives as tools to interrupt execution of the aging program. 4. Age-related eye disease. SkQ1 returns vision to blind animals

Mitochondria-targeted cationic plastoquinone derivative SkQ1 (10-(6′-plastoquinonyl) decyltriphenylphosphonium) has been investigated as a potential tool for treating a number of ROS-related ocular diseases. In OXYS rats suffering from a ROS-induced progeria, very small amounts of SkQ1 (50 nmol/kg per day) added to food were found to prevent development of age_induced cataract and retinopathies of the eye, lipid peroxidation and protein carbonylation in skeletal muscles, as well as a decrease in bone mineralization. Instillation of drops of 250 nM SkQ1 reversed cataract and retinopathies in 3-12-month-old (but not in 24-month-old) OXYS rats. In rabbits, experimental uveitis and glaucoma were induced by immunization with arrestin and injections of hydroxypropyl methyl cellulose to the eye anterior sector, respectively. Uveitis was found to be prevented or reversed by instillation of 250 nM SkQ1 drops (four drops per day). Development of glaucoma was retarded by drops of 5 μM SkQ1 (one drop daily). SkQ1 was tested in veterinarian practice. A totally of 271 animals (dogs, cats, and horses) suffering from retinopathies, uveitis, conjunctivitis, and cornea diseases were treated with drops of 250 nM SkQ1. In 242 cases, positive therapeutic effect was obvious. Among animals suffering from retinopathies, 89 were blind. In 67 cases, vision returned after SkQ1 treatment. In ex vivo studies of cultivated posterior retina sector, it was found that 20 nM SkQ1 strongly decreased macrophagal transformation of the retinal pigmented epithelial cells, an effect which might explain some of the above SkQ1 activities. It is concluded that low concentrations of SkQ1 are promising in treating retinopathies, cataract, uveitis, glaucoma, and some other ocular diseases. Electronic Supplementary Material  Supplementary material is available for this article at and is accessible for authorized users. Published in Russian in Biokhimiya, 2008, Vol. 73, No. 12, pp. 1641–1654.     

Possible effect of structural phase transition in the reactive center of Rhodobacter sphaeroides on the rate of dark adaptation of photooxidized bacteriochlorophyll from primary quinone

The dependence of the rate of dark recombination between the photooxidized primary donor--dimer bacteriochlorophyll molecule (P) and reduced primary quinone acceptor (QA), P+QA(-)-->PQA was studied in photosynthetic reaction centers (RC) from Rhodobacter sphaeroides in the temperature range of 100-320 K. Control RC preparations, RC species with the removed H-subunit as well as RC samples with the hydrogen bonds network modified by isotopic D2O-H2O substitution were investigated. An anomalous temperature dependence of the recombination time (tau rec) of dark reaction P+QA(-)-->PQA was found for all RC samples. It was found that upon heating from 120 to 290 K tau rec increased 2.5 fold. However, upon further heating to 320 K, tau rec decreased again. The temperature dependences of the P+QA(-)-->PQA recombination time were compared with those of the thermodepolarization current of RC preparations in the same temperature range. The temperature curve of the thermodepolarization current was also nonmonotonous. The theoretical interpretation of the temperature dependence of tau rec as well as of the thermodepolarization current was made in the framework of the theory of structural phase transitions within the hydrogen bond network in the water-protein surrounding of the redox centers participating in the electron transfer reactions.     

Changes in the ratio of microsomal electron carriers in reconstituted microsomal membranes

The reconstitution of microsomal membrane monooxygenase system with variable contents of the hydroxylating chain enzymatic components was carried out. It was found that during self-assembly of microsomal membranes solubilized with 4% sodium cholate and gel filtration through Sephadex LH-20 in the presence of isolated microsomal enzymes, two forms of cytochrome P-450, i. e. phenobarbital- and 3-methylcholantrene-induced ones, and NADPH-cytochrome P-450 reductase, the exogenous enzymes are incorporated into the microsomal membrane matrices of control and methyl-cholantrene-treated animals. In the membranes reconstituted from the microsomes of the methylcholantrene-induced animals the catalytic activity of cytochrome P-448 in the metabolism of benz(a)pyrene at varying cytochrome P-448 and NADPH-cytochrome P-450 reductase contents were investigated.     

Correlation between cytochrome P-448 content and benzopyrene hydroxylase activity during the induction of microsomal monooxygenases using methylcholanthrene-type xenobiotics

Using antibodies against electrophoretically homogeneous cytochrome P-448 from rat liver microsomes induced by 3-methylcholanthrene, the changes in the immunologic identity and contents by cytochrome P-448 induced by 3-methylcholanthrene, 3.4-benzpyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), were studied. No cytochrome P-448 was detected in the liver microsomes of control or phenobarbital-induced rats. This form of the cytochrome makes up to about 35% of the total content of the CO-binding hemoprotein during TCDD induction and up to 90% during 3-methylcholanthrene and 3,4-benzpyrene induction. On the other hand, 3-methylcholanthrene, 3,4-benzpyrene and TCDD significantly and equally activates the cytochrome P-448-dependent benzpyrene hydroxylase, since the antibodies against cytochrome P-448 inhibit benzpyrene metabolism in the microsomes by 85-90%. The possible reasons for the TCDD-induced increase in the catalytic activity of cytochrome P-448 as compared to the immunologically identical cytochrome P-448 induced by 3-methylcholanthrene and 3,4-benzpyrene, are discussed.     

Mechanism of inhibiting the cytochrome P-450-dependent monooxygenase system in liver with fluorocarbons]

The inducer of the liver monooxygenase system perfluorodecalin added to microsomes as a submicron emulsion forms an enzyme-substrate complex with cytochrome P-450. The K(app) values for the perfluorodecalin binding to cytochrome P-450 in microsomes isolated from the livers of control and phenobarbital-treated rats are 5 x 10(-5) M and 2.3 x 10(-6) M, respectively. Perfluorodecalin competitively inhibits the binding of substrates to cytochrome P-450 and decreases the rates of monooxygenase reactions. Perfluorodecalin extrusion from the active center of cytochrome P-450 occurs when an excess of perfluorocarbons non-interacting with cytochrome P-450 is added to microsomes. There is a significant vagueness in the rates of various monooxygenase reactions because of simultaneous induction and inhibition of monooxygenase enzymes after perfluorodecalin administration to rats. The data obtained are consistent with the hypothesis that constitutive forms of cytochrome P-450 are primary receptors for xenobiotic-inducers of phenobarbital-type cytochrome P-450 isoforms.