Antimicrobiai properties of aromatic compounds of plant origin

The antimicrobial action of 11 compounds involving guaiacyl- and syringyl-like structures (low-molecular-weight part of lignin), gallic acid and its derivatives, cinnamic acid and its derivatives, veratric acid, anisic acid and crotonic acid (a total of 25 compounds) against bacteria, yeast-like organisms and protozoa was examined. Aromatic compounds modified in the C-side chain and aldehydes were effective preferentially againstTrichomonas vaginalis, whereas against bacteria and yeast-like organisms eugenol was the most effective inhibitor. Dedicated to Academician A. Blažej on the occasion of his 60th birthday.     

Isolation,origin and properties of enucleate plant microplasts

Summary Auxin-induced highly vacuolated thin-walled callus cells of several plant species, when ruptured, released large numbers of subcellular units most of which were enucleate. These enucleate microplasts are surrounded by an inner membrane of the cell, most probably derived from the tonoplast. When microplasts isolated fromSaintpaulia callus were cultured in a medium supplemented with growth substances they formed a thin wall and underwent budding. Microplasts could be useful for various studies in plant cell biology and for genetic manipulations.     

Immunochemical characteristics of plant pollen allergoid

Allergen from ragweed pollen was treated with formaldehyde to obtain allergoid. The preparation obtained loses to a significant extent its ability to react not only with allergic antibodies (reagins) of the patients but also with precipitins of sera from rabbits hyperimmunized with allergen. Immunoelectrophoresis in agarose allowed a conclusion that formaldehyde blocks up to 4--5 antigens possessing a higher positive electrophoretic charge. Electrophoresis in polyacrylamide gel has shown that concurrently there occur stabilization and enlargement of protein molecules.     

On the origin of family 1 plant glycosyltransferases

The phylogeny of highly divergent multigene families is often difficult to validate but can be substantiated by inclusion of data outside of the phylogeny, such as signature motifs, intron splice site conservation, unique substitutions of conserved residues, similar gene functions, and out groups. The Family 1 Glycosyltransferases (UGTs) comprises such a highly divergent, polyphyletic multigene family. Phylogenetic comparisons of UGTs from plants, animals, fungi, bacteria, and viruses reveal that plant UGTs represent three distinct clades. The majority of the plant sequences appears to be monophyletic and have diverged after the bifurcation of the animal/fungi/plant kingdoms. The two minor clades contain the sterol and lipid glycosyltransferases and each show more homology to non-plant sequences. The lipid glycosyltransferase clade is homologous to bacterial lipid glycosyltransferases and reflects the bacterial origin of chloroplasts. The fully sequenced Arabidopsis thaliana genome contains 120 UGTs including 8 apparent pseudogenes. The phylogeny of plant glycosyltransferases is substantiated with complete phylogenetic analysis of the A. thaliana UGT multigene family, including intron-exon organization and chromosomal localization.     

Eucaryotic elongation factors Ts is an integral component of rabbit reticulocyte elongation factor 1.

Elongation factor 1 (EF-1) was purified from rabbit reticulocytes and found to contain at least two distinct polypeptides: one of Mr 53 000 and one of Mr 30 000. The 30 000-Mr polypeptide was purified from EF-1 by treatment of the factor with 5.4 M guanidine . HCl and subsequent chromatography on DEAE-BioGel A in the presence of 5 M urea. By a number of functional criteria, the 30 000-Mr polypeptide was found to be the eucaryotic elongation factor Ts (eEF-Ts). These criteria include the ability of the polypeptide to stimulate Artemia salina eEF-Tu-dependent binding of aminoacyl-tRNA to 80-S ribosomes as well as eEF-Tu + EF-2-dependent polyphenylalanine synthesis. The reticulocyte factor also markedly increased the rate of exchange of eEF-Tu . gdp complexes with free GTP. Furthermore, rabbit antibodies to EF-1 from A. salina which was previously shown to contain eEF-Ts [Slobin, L. I. and M?ller, W. (1978) Eur. J. Biochem. 84, 69--77] were found to cross-react with reticulocyte eEF-Ts, suggesting extensive structural homology between brine shrimp and rabbit eEF-Ts. The demonstration that eEF-Ts is and integral component of EF-1 from such diverse sources as brine shrimp and rabbit reticulocytes supports the conclusion that the factor is universally present in eucaryotic EF-1.     

Immunochemical properties of D-amino-acid oxidase

Antiserum against homogeneous hog kidney D-amino-acid oxidase (D-amino-acid: oxygen oxidoreductase (deaminating), EC 1.4.3.3) was elicited in rabbits, and monospecific antibodies were prepared by affinity chromatography. The antibodies inhibited up to 90% of hog D-amino-acid oxidase activity, and 100% of the enzyme could be immunoprecipitated. The antibodies inhibited both holoenzyme and reconstituted apoprotein to a similar degree, indicating that they did not interfere with the FAD-binding site of the protein. The antibodies inhibited D-amino-acid oxidase activity from other mammalian species to a similar degree, while the enzyme activities from birds, amphibians, fishes and yeast were inhibited and immunoprecipitated to lower extents. In immunoblotting experiments, after SDS-polyacrylamide gel electrophoresis, the antibodies recognized a single band of about 40 kDa in all the species analyzed, and the entity of the signal was inversely related to the phylogenetic distance from mammals. The antibodies did not inhibit D-alanine dehydrogenase activity from Escherichia coli, but gave positive bands in immunoblotting.     

Immunochemical properties of vertebrate alpha-crystallins

A competitive radioimmunoassay was used to determine the reactivities of alpha-crystallins from 13 species with antibodies directed toward calf alpha-crystallin. The results indicate that species as diverse as human and dogfish share the same number of crossreacting antigenic determinants. The various alpha-crystallins can be distinguished only on the basis of their differing affinities for the antiserum. Hydrophilicity profiles for alpha A and alpha B polypeptides of all species were found to be remarkably similar. On the basis of these, four major sequential determinants could be predicted for each polypeptide. The location and sequence of these determinants were found to be essentially conserved in all alpha-crystallins examined. These results are in agreement with the observed crossreactivities. However, there was little obvious correlation between substitutions in determinants and observed variations in respective alpha-crystallin/antibody affinities. Conservation of antigenic determinants over such a wide evolutionary range may reflect stringent constraints on the overall surface and three-dimensional structure of vertebrate alpha-crystallins.     

The reflectance properties of plant internodes modify elongation responses to lateral far-red radiation

The quality and quantity of light reflected from Nicotinia tabacum L. internodes was monitored as the angle of incidence was varied. Reflectance of incident light, which was either normal or longitudinal to the internode axis, was investigated. Increasing the angle of incidence caused a greater proportion of incident light to be reflected. Light striking N. tabacum internodes was always modified prior to reflection, and smaller incident angles produced greater modification of the reflected light quality. At larger angles, interactions with the internode were reduced. As a parallel investigation, the extension growth rate of light-grown Sinapis alba L. seedlings was monitored continuously using sensitive linear displacement transducers. When the angle of illumination by fibre-optic probes, presenting far-red light to the growing internode, was changed from 0° to 45°, an increase was observed in stem extension rate. There is a possibility that this rate increase was the result of a fall in the red:far-red ratio (R:FR) present inside the plant internode as the angle of incidence was altered. However, it is more likely that it was due to the larger surface area of stem being illuminated. The consequences of these observations are discussed in relation to the potential influence of such modified reflections on canopy light environments and resultant shade responses which may occur when light of known R:FR impinges on plant internodes at angles other than 0°. The possibility is discussed that plants may perceive the quality of reflected radiation from neighbouring plants to be substantially different dependent upon the angle at which it is reflected.     

Immunochemical comparison of peptide angiogenic factors

A panel of 40 monoclonal antibodies was constructed in response to cationic endothelial cell growth factor (c-ECGF), the cationic peptide mitogen isolated from endothelial mitogen. The monoclonal antibodies were assayed by dot blot for immunoreactivity to various other peptide angiogenic factors. The panel of monoclonal antibodies to c-ECGF exhibited complete cross-reactivity with pituitary fibroblast growth factor and sarcoma-derived growth factor. A group of 28 monoclonal antibodies was found to exhibit reactivity to anionic endothelial mitogen (a-ECGF), brain fibroblast growth factor, endothelial cell growth factor, and retina-derived growth factor. None of the monoclonal antibodies was found to react with epidermal growth factor or platelet-derived growth factor. These data provide an immunological basis for grouping heparin-binding endothelial cell growth factors into anionic and cationic groups.     

Purification and properties of rabbit reticulocyte elongation factor 1.

Elongation factor 1 has been purified about 100-fold from the lysate of rabbit reticulocytes. The native enzyme is highly asymmetric ($\text{f}\text{f}{}_0\text{= 1.53}$) and has a molecular weight of 450,000. Polyacrylamide-gel electrophoresis in sodium dodecyl sulfate shows two major bands with molecular weights of about 53,000 and 50,000. Partially purified phospholipase C and AB preparations and elastase cause dissociation of the aggregate form of the enzyme to an active form which has a molecular weight of about 50,000. The effect of these phospholipase preparations is unexplained since rabbit reticulocyte elongation factor 1 contains little or no phospholipid. A protease contamination has been considered but no evidence of protease activity has been detected in the phospholipase preparations. In aminoacyl-tRNA binding, elongation factor 1 appears to show very little, if any, turnover. However, in the presence of elongation factor 2, under conditions where polymerization occurs, elongation factor 1 functions catalytically.     

Isolation and properties of elongation factor 1 from Saccharomyces cerevisiae

Polypeptide elongation factor 1 was isolated from yeast postribosomal supernatant. The highly purified factor was resolved on Ultrogel AcA-44 into two complementary fractions. One of these fractions contained two different polypeptide chains corresponding to a Ts-like elongation factor EF-1 beta gamma. The other fraction represented the light form of the factor, designated EF-1 alpha, with a molecular weight of approximately 50,000. The obtained results indicate that EF-1 from lower eukaryotes is also composed of three distinct polypeptides.     

Eukaryotic protein elongation factors

In eukaryotes, peptide chain elongation is mediated by elongation factors EF-1 and EF-2. EF-1 is composed of a nucleotide-binding protein EF-1 alpha, and a nucleotide exchange protein complex, EF-1 beta gamma, while EF-2 catalyses the translocation of peptidyl-tRNA on the ribosome. Elongation factors are highly conserved among different species and may be involved in functions other than protein synthesis, such as organization of the mitotic apparatus, signal transduction, developmental regulation, ageing and transformation. Yeast contains a third factor, EF-3, whose structure and function is not yet well understood.     

Immunochemical properties ofVibrio cholerae LPS

Immunochemical analysis of LPS isolated fromVibrio cholerae O1 and non O1 showed that this macromolecular complex shares common antigenic epitopes in the sugar moiety. The epitopes can be detected after mild alkaline hydrolysis of LPSin vitro. Membrane-associating activity of both O1 and non O1 LPS did not indicate any differences of the species.