Isolation and characterization of highly liganded protein from brewer's barley grain

Two basic proteins, HLP-1 and HLP-2, were isolated from brewer's barley grain (Hordeum vulgare L.) and characterized as glycoproteins with molecular masses of 16 and 13 kDa and pI values of 7.4 and 8.8, respectively. They could bind sugars, metal ions, and both hydrophobic and hydrophylic molecules of low molecular mass. These characteristics may be related to their potential plant-protecting role.     

The spectral analysis of syllables in patients using dentures

Changes in the oral cavity resulting from the loss of teeth and the ensuing reconstruction of a set of teeth by dentures (partial or complete) may cause changes in the speech and voice of the patient. The aim of the present investigation was to study the changes in speech and voice in patients suffering from teeth loss and the degree of speech improvement using dentures. Voice and speech parameters of a set of tested syllables were analysed in 10 patients at the 2nd Clinic of Stomatology. The analysis was carried out by means of an FFT, SoundForge 5.0 programme. Differently expressed acoustic changes in both consonants and vowels were ascertained in a percentage of the patients under examination. These concerned especially the sibilant ("s", "(see text)"), labiodental ("f", "v") and vibrating ("r", "(see text)") consonants. Changes in the FFT spectrum and air leakage in constrictive consonants were also found. In some patients the vowels, especially the closed ones ("i", "u"), may change their fundamental frequency and show noise admixture manifested as a blurred delimitation of the formants. A denture should, inter alia, render it possible for the patient to produce the same articulation to which he/she had been accustomed before the loss of teeth. For the construction of dentures the most important factors from a phonetic point of view appear to be the following: overbite, overjet, the height of the plate, the thickness of the palatal material, the incisor position, and the modelling of the ruga palatina on the hard palate. In case of wrong denture construction the acoustic changes may continue, resulting in the patient's stress load dependent upon sex, age, psychic condition and seriousness of the problem.     

Effect of<Emphasis Type="Italic">Glomus intraradices</Emphasis> isolated from Pb-contaminated soil on Pb uptake by<Emphasis Type="Italic">Agrostis capillaris</Emphasis> is changed by its cultivation in a metal-free substrate

Development and heavy metal tolerance of two cultivation lineages of the indigenous isolate of arbuscular mycorrhizal fungus (AMF)Glomus intraradices PH5 were compared in a pot experiment in soil from lead (Pb) smelter waste deposits. One lineage was sub-cultured in original Pb-contaminated soil; the second one was maintained for 13 months in an inert substrate (river sand) without Pb stress. The contribution of these cultivation lineages to the Pb uptake and accumulation by the host plantAgrostis capillaris was investigated. The experiment was conducted in a compartmented system where the lateral compartments withAgrostis seedlings were separated from the central pot containing 4-week olderAgrostis plants by a nylon mesh for allowing out-growing of extraradical mycelium (ERM) from the pot. No differences in mycorrhizal colonization, ERM length and viability were observed between the two lineages ofG. intraradices PH5 in the soil of the isolate origin. However, the ability to support plant growth and Pb uptake differed between the lineages and also between the plants in the central pots and the lateral compartments. The growth of the plants in the central pots was positively affected by AMF inoculation. The plants inoculated with the lineage maintained in original soil showed larger shoot biomass and higher shoot P content as compared to the other inoculation treatments. The shoot Pb concentration of these plants was lower when compared to the plants inoculated with the lineage sub-cultured in the inert substrate. However the concentration did not differ from non-mycorrhizal control or from the reference isolateG. intraradices BEG75 from non-contaminated soil. Also shoot Pb contents were similar for all inoculation treatments. The development ofG. intraradices BEG75 in the contaminated soil was very poor; this isolate was not able to initiate colonization of seedlings in lateral compartments. In lateral compartments, growth of seedlings in contaminated soil was inhibited by theG. intraradices PH5 lineage maintained in the inert substrate. Pb translocation from the seedling roots to shoots was increased for plants inoculated with either lineage as compared to the non-mycorrhizal control; however, the increase for the lineage cultivated in the inert substrate was significantly higher in comparison with that maintained in the original soil. After 13 months of cultivation in a metal free substrate, theG. intraradices isolate from Pb contaminated soil did not lose its tolerance to Pb as regards colonization of plant roots and growth of ERM in the soil of its origin. However, its ability to support plant growth and to prevent Pb translocation from the roots to the shoots was decreased.     

Do phytotropins inhibit auxin efflux by impairing vesicle traffic?

Phytotropins such as 1-N-naphthylphthalamic acid (NPA) strongly inhibit auxin efflux, but the mechanism of this inhibition remains unknown. Auxin efflux is also strongly decreased by the vesicle trafficking inhibitor brefeldin A (BFA). Using suspension-cultured interphase cells of the BY-2 tobacco (Nicotiana tabacum L. cv Bright-Yellow 2) cell line, we compared the effects of NPA and BFA on auxin accumulation and on the arrangement of the cytoskeleton and endoplasmic reticulum (ER). The inhibition of auxin efflux (stimulation of net accumulation) by both NPA and BFA occurred rapidly with no measurable lag. NPA had no observable effect on the arrangement of microtubules, actin filaments, or ER. Thus, its inhibitory effect on auxin efflux was not mediated by perturbation of the cytoskeletal system and ER. BFA, however, caused substantial alterations to the arrangement of actin filaments and ER, including a characteristic accumulation of actin in the perinuclear cytoplasm. Even at saturating concentrations, NPA inhibited net auxin efflux far more effectively than did BFA. Therefore, a proportion of the NPA-sensitive auxin efflux carriers may be protected from the action of BFA. Maximum inhibition of auxin efflux occurred at concentrations of NPA substantially below those previously reported to be necessary to perturb vesicle trafficking. We found no evidence to support recent suggestions that the action of auxin transport inhibitors is mediated by a general inhibition of vesicle-mediated protein traffic to the plasma membrane.     

Combination of modeling and experiment in structure analysis of intercalated layer silicates

A strategy for the structure analysis of intercalated layer silicates based on a combination of modeling (i.e. force field calculations) and experiment is presented. Modeling in conjunction with experiment enables us to analyze the disordered intercalated structures of layer silicates where conventional diffraction analysis fails. Experiment plays a key role in the modeling strategy and in corroboration of the modeling results. X-ray powder diffraction and IR spectroscopy were found to be very useful complementary experiments to molecular modeling. Molecular mechanics and molecular dynamics simulations were carried out in the Cerius2 and Materials Studio modeling environments. An overview is given of the structures of layer silicates, especially smectites intercalated with various inorganic and organic guest species. Special attention is paid to the ordering of guests in the interlayer space, as it is important for the practical applications of these intercalates, where the interlayer porosity, photofunctions, etc. must be controlled. Figure Structure of montmorillonite intercalated with octadecylamine via ion-dipole interaction with the maximum concentration of guests corresponding to the monolayer arrangement of guests with basal spacing 33.3 A. The Na cations remaining in the interlayer are visualized as pink balls     

Mitogen-activated protein kinases in the acute diabetic myocardium

Diabetes mellitus (DM) causes myocardial remodeling on the subcellular level and alterations in the function of the cell membranes ion transport systems resulting in contractile dysfunction. The present study was aimed to investigate the expression and activation of mitogen-activated protein kinases (MAPKs) and their possible role in the acute diabetic rat hearts. Rats were injected with single dose of streptozotocin (45 mg/kg, i.v.), and after 1 week the disease was manifested by hyperglycemia and cardiac dysfunction. The Langendorff-perfused hearts were subjected to ischemia (5 or 30 min occlusion of LAD coronary artery). The protein pattern in cytosolic fraction of the heart tissue was determined after electrophoretic separation. The levels and activation of MAPKs were determined by Western blot analysis using specific antibodies. No differences between the diabetics and controls in the level of ERKs were found at baseline. However, in DM samples ERKs phosphorylation was markedly increased, and further changes occurred during ischemia. Also content of phoshorylated c-Raf kinase (an upstream activator of ERKs) was slightly increased at baseline conditions in the diabetic samples. In contrast, no significant changes in the contents and phosphorylation of p38-MAPK were observed at baseline. But some differences in the p38-MAPK phosphorylation were found during ischemia.The results show that differential pattern of protein kinase cascades activation in the diabetic hearts might be account for the modulation of their response to ischemia.     

2,6,8,9-tetrasubstituted purines as new CDK1 inhibitors

Purine inhibitors of cyclin-dependent kinases attract attention as potential anticancer drugs because their first representative roscovitine recently entered clinical trials. Although well described in terms of structure-activity relationships, we still present here a novel modification of the purine scaffold influencing their inhibitory properties. The introduced C-8 substituents, however, lowered the CDK inhibitory activity of roscovitine, whereas the antiproliferative potential of several derivatives remained high.     

Selective enzymic esterification of free fatty acids with n-butanol under microwave irradiation and under classical heating

Selective enzymic esterification of free fatty acids, obtained from blackcurrant oil by chemical saponification, with n-butanol using four immobilized lipases under microwave irradiation and under classical heating was studied. A positive effect of microwave irradiation on chemical yields of the products of the enzymic reactions and specificity of lipases were observed in comparison with a controlled heating in an incubator equipped with shaking (classical heating) applied during the identical enzyme-mediated processes. The maximum quantity of -linolenic acid (30%) was obtained with Lipozyme used as biocatalyst of the reaction under microwave irradiation. The maximum quantity of butyl -linolenate (20%) was obtained by a Pseudomonas cepacia lipase catalyzed esterification under classical heating.