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PubMed1965

THE LYSIS OF CELL WALLS OF GROUP A STREPTOCOCCI BY STREPTOMYCES ALBUS ENZYME TREATED WITH DIISOPROPYL FLUOROPHOSPHATE. CHARACTERISTICS OF THE LYTIC REACTION AND THE SOLUBLE CELL WALL FRAGMENTS.

Diisopropyl fluorophosphate (DFP) effectively inhibited proteolytic activity in preparations of partially purified Streptomyces albus enzyme used to lyse cell walls of Group A streptococci. Lysis of non-trypsinized Group A cell walls with DFP-treated S. albus enzyme released a soluble protein fraction containing antigenic type-specific M protein, a carbohydrate fraction consisting of Group A and a small amount of A-variant polysaccharides, and a dialyzable fraction. The similarities of the products of DFP-treated S. albus enzyme lysis of streptococcal cell walls to those released by phage muralytic enzyme furnish additional evidence of the close relationship of these wall lysins. In view of small differences in electrophoretic mobility, immunodiffusion, and chemical composition, it is suggested that Group A streptococcal cell wall polysaccharide dissolved by DFP-S. albus enzyme consists of a spectrum of molecules having the same immunological determinants but differing in content of conjugated mucopeptide.

Bacteriolysis↗
PubMed1975

Isolation, ultrastructure and chemical composition of the outermost layer ("exo-layer") of the Epidermophyton floccosum cell wall.

The outer-most layer ("exo-layer") of the wall was isolated from cell walls of Epidermophyton floccosum. The pure cell walls, obtained by disruption in a Ribi cell fractionator, sonication and centrifugation, were digested with snail enzyme for 12 h. Thereafter, the exo-layer preparation was obtained as the fraction resistant to the snail enzyme. Electron microscopy showed that the exo-layer is a thin, stranded network structure 10-20 nm thick. Chemical analysis of the exo-layer showed that the main components are protein (63 percent), mannose (10 percent) and glucosamine (17 percent). Sodium dodecyl sulfate polyacrylamide gel electrophoresis has revealed that the main band is a glycoprotein containing mannose.

Amino Acids↗
PubMed1980

Lipids as a principle for the identification of archaebacteria.

The 'Archaebacteria' consist of several distinct subgroups including methanogens, extreme halophiles and specific thermoacidophiles. These bacteria are distinct from other bacteria with respect to their characteristic RNA compositions, the absence of muramic acid in the cell walls and the predominance of nonsaponifiable [correction of nonsaponifable] lipids. The lipid composition of the archaebacteria consists of isoprenoid and hydroisoprenoid hydrocarbons and isopranyl glycerol ether lipids. The pathways for the biosynthesis of the lipid components are those shared by most microorganisms and demonstrate a close relationship; however, an independent line of descent is indicated by the formation of the isopranyl glycerol ether lipids. This discontinuity formulates a point for delineating the early stages of biological evolution and for dividing bacteria into two subgroups.

Archaea↗
PubMed1991

A membrane protein is required for bacteriophage c2 infection of Lactococcus lactis subsp. lactis C2.

Phage-resistant mutants, isolated from cultures of Lactococcus lactis subsp. lactis C2 infected with phage c2, did not form plaques but bound phage normally. The mutants were sensitive to another phage, sk1, although the number of plaques was reduced approximately 56% and the plaques were four times smaller. Binding to phage sk1 was reduced about 10%. Another group of phage-resistant mutants, isolated from cultures infected with phage sk1, bound normally to both phages c2 and sk1 but did not form plaques with either phage. Carbohydrate analyses by gas chromatography of the cell walls showed no significant differences in saccharide compositions between the wild-type and phage-resistant cells. However, a difference was observed in the interactions of the phage with the cytoplasmic membranes. Membranes from the wild-type cells, but not mutant cells, inactivated phage c2. Phage sk1 was not inactivated by membrane from either strain. Treatment of wild-type membranes with proteinase K eliminated the ability of the membrane to inactivate the phage, whereas treatment with mutanolysin had no effect. On the basis of this ability to inactivate the phage, a membrane protein was partially purified by gel filtration and ion-exchange chromatography. Under nondenaturing conditions, the phage-inactivating protein has an apparent Mr of approximately 350,000. The protein has an apparent subunit size of 32 kDa, which suggests that it normally exists as a multimer with 10 to 12 subunits or in association with other membrane components. It is proposed that this protein is required for phage c2 infection.

Bacterial Proteins↗
PubMed1994

Cell wall proteins in seedling cotyledons of Prosopis chilensis.

Four cell wall proteins of cotyledons of Prosopis chilensis seedlings were characterized by PAGE and Western analyses using a polyclonal antibody, generated against soybean seed coat extensin. These proteins had M(r)s of 180,000, 126,000, 107,000 and 63,000, as determined by SDS-PAGE. The proteins exhibited a fluorescent positive reaction with dansylhydrazine suggesting that they are glycoproteins; they did not show peroxidase activity. The cell wall proteins were also characterized by their amino acid composition and by their amino-terminal sequence. These analyses revealed that there are two groups of related cell wall proteins in the cotyledons. The first group comprises the proteins of M(r)s 180,000, 126,000, 107,000 which are rich in glutamic acid/glutamine and aspartic acid/asparagine and they have almost identical NH2-terminal sequences. The second group comprises the M(r) 63,000 protein which is rich in proline, glycine, valine and tyrosine, with an NH2-terminal sequence which was very similar to that of soybean proline-rich proteins.

Amino Acid Sequence↗
PubMed1990

[The detection of streptococcal cell-wall proteins that form complexes with human macroglobulins].

The composition of the extracts of the cultures of individual streptococcal strains, studied by immunoblotting techniques, has been shown to contain proteins with a molecular weight of 70-80 KD. These proteins have pronounced affinity to human macroglobulins: alpha-macroglobulin, alpha-glycoprotein associated with pregnancy and protein A. The significance of this phenomenon on the cellular and somatic levels is discussed.

Bacterial Proteins↗
PubMed1998

Cell walls: structures and signals.

Cell walls harbor proteins and polysaccharides able to condition the development of a plant. In the past year, genes and enzymes modulating the composition and physical properties of walls have been characterized, and wall composition has been linked to the way a cell interacts with another cell, and to the way in which it differentiates. The sum of the signaling and physical activities of a cell wall may explain much about the control of development.

Arabidopsis↗
PubMed1992

[New reconstruction method for defect of chest wall using composite graft].

In the case of a 64-year-old man squamous cell carcinoma in the left lung with metastasis to the rib, we excised the affected portion of the chest wall and used a composite graft, a combination hydroxyapatite (HAP) filler, for reconstruction with good results. HAP filler is a ceramic that combines the calcium phosphate apatite hydroxide with 3-calcium phosphate. The Dacron fabric used was made of polyethylene terephthalate fiber. Two layers of Dacron fabric were laid together, stitched to the rib with nylon thread, and the resulting tubular cavity packed with HAP filler to create an artificial rib. The intercostal muscle was sandwiched between the layers of Dacron fabric and the ends of the natural rib laid across those of the artificial one. We used the periosteum and intercostal muscle to integrate the graft and complete reconstruction. Postoperative recovery was good, and there was no visible sign of deformation at the graft site. Even in palpation we were unable to tell that the rib was artificial.

Biocompatible Materials↗
PubMed1985

Medium-dependent properties of mycoplasmas.

Without a cell wall, the morphology, growth rate, and composition of mycoplasmas are culture media-dependent with variable properties best described as environmentally related. The adaptation of mycoplasmas to either a tissue cell or cell-free culture media, with dependency upon specific animal or plant products for survival, has led to investigations of their human host-related properties. The influence of culture media on the antibiotic sensitivities of mycoplasmas was measured by use of three different broths in two different assay systems. The variable results indicate that the inhibition of mycoplasma protein synthesis or growth may also be host-tissue dependent. The addition of noninhibitory penicillins to different culture media was found to affect the composition and antigenicity of some mycoplasmas. Using the complement fixation test, we found some human sera that were more reactive than rabbit antisera to mycoplasmas cultured in human synovial broth or in myelin-enriched broth. Mycoplasmas cultured in human lung broth and pig lung broth had media-dependent antigenicity. The antigenicity and the growth of mycoplasmas were found to depend on the proteolytic enzymes used to provide the essential peptides in tissue broths. The media-affected mycoplasmas indicate the presence of species-, strain-, and tissue-specific antigen sites that may determine immunopathogenicity in the genetically susceptible host.

Adaptation, Physiological↗
PubMed2002

Nuclear magnetic resonance and plant metabolic engineering.

Nuclear magnetic resonance (NMR) can be used to measure metabolite levels and metabolic fluxes, to probe the intracellular environment, and to follow transport and energetics nondestructively. NMR methods are therefore powerful aids to understanding plant metabolism and physiology. Both spectroscopy and imaging can help overcome the unique challenges that plants present to the metabolic engineer by detecting, identifying, quantifying, and localizing novel metabolites in vivo and in extracts; revealing the composition and physical state of cell wall and other polymers; allowing the identification of active pathways; providing quantitative measures of metabolic flux; and testing hypotheses about the effects of engineered traits on plant physiological function. The aim of this review is to highlight recent studies in which NMR has contributed to metabolic engineering of plants and to illustrate the unique characteristics of NMR measurements that give it the potential to make greater contributions in the future.

Biopolymers↗
PubMed1995

Xylem-specific gene expression in loblolly pine.

Two genes preferentially expressed in differentiating xylem of loblolly pine (Pinus taeda L.) were cloned from cDNA and genomic libraries and designated PtX3H6 and PtX14A9. Transcripts of PtX3H6 and PtX14A9 are very abundant in differentiating xylem, less abundant in needles, and very low or non-detectable in embryos and megagametophytes. PtX3H6 contains a putative signal peptide, a threonine-rich region, a proline-rich region, and a hydrophobic tail. Repeats of Pro-Pro-Pro-Val-X-X are similar to repeats found in proline-rich cell wall proteins. The amino acid compositions of PtX3H6 and PtX14A9 are similar to those of arabinogalactan proteins (AGPs). PtX14A9 contains an 8 amino acid sequence similar to amino terminal sequences of ryegrass, carrot and rose AGPs. Upstream sequences have been determined from genomic clones encoding PtX3H6 and PtX14A9. A 7 bp sequence found in the 5' flanking regions of both genes has previously been shown to be involved in the vascular-specific expression of GRP 1.8, a glycine-rich protein found in bean. The sequence is also present upstream of another glycine-rich protein from bean, GRP 1.0, and may be partially responsible for the xylem-specific expression of pTx3H6 and PtX14A9.

Amino Acid Sequence↗
PubMed1990

Efficient production of human alpha-amylase by a Bacillus brevis mutant.

A cDNA for mature human salivary alpha-amylase was directly joined to a sequence encoding the signal peptide of the middle wall protein (MWP) gene of Bacillus brevis 47. This hybrid gene was placed downstream from the multiple promoter region of the MWP gene on a low copy-number plasmid vector, pHW1. B. brevis 47 carrying the plasmid produced 0.9 mg/l of active human alpha-amylase in the medium. A B. brevis 47 mutant obtained on mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine produced an increased amount of the alpha-amylase (6 mg/l). When the fused gene was inserted into a high copy-number expression vector, pNU200, and then introduced into the mutant, a large amount (60 mg/l) of the alpha-amylase was produced in the medium. The alpha-amylase showed approximately the same specific activity and molecular weight as those of the natural enzyme. The mutant showed higher sensitivity to various antibiotics than the original strain, and altered cell wall and cytoplasmic membrane protein compositions. The results of reversion analysis suggested that a single mutation is responsible for the above phenotypes and hyper-productivity of human alpha-amylase.

Amino Acid Sequence↗
PubMed1978

Ultrastructural detection of Haemophilus ducreyi in biopsies of chancroid.

During an endemic appearance of chancroids (26 cases) in Berlin (West) coccobacilli were disclosed in biopsies by electron microscopy. The bacteria were aggregated predominantly in groups in the extracellular space. Their cell wall is approximately 120 A thick and trilaminar as in Gram-negative bacteria. Concerning the cell wall structure and the cytoplasmic composition, the detected coccobacilli are identical to culturally grown Haemophilus ducreyi obtained from chancroids.

Chancroid↗
PubMed1998

Production and structure elucidation of di- and oligosaccharide lipids (biosurfactants) from Tsukamurella sp. nov.

The bacterium Tsukamurella sp. nov., isolated from soil, was found to produce novel glycolipids when grown on sunflower oil as the sole carbon source. The glycolipids were isolated by chromatography on silica columns and their structures elucidated using a combination of multidimensional NMR and MS techniques. The three main components are 2,3-di-O-acyl-alpha-D-glucopyranosyl-(1-1)-alpha-D-glucopyranose, 2,3-di-O-acyl-beta-D-glucopyranosyl-(1-2)-4,6-di-O-acyl-alpha-D- glucopyranosyl-(1-1)-alpha-D-glucopyranose and 2,3-di-O-acyl-beta-D-glucopyranosyl-(1-2)-beta-D-galactopyranosyl- (1-6)-4,6-di-O-acyl-alpha-D-glucopyranosyl-(1-1)-alpha-D- glucopyranosyl which are linked to fatty acids varying in chain length from C4 to C18. The glycolipids are mainly extracellular but are also found attached to the cell walls. During the cultivation the composition of the glycolipids changed from disaccharide- to tri- and tetrasaccharide lipids. The glycolipids show good surface-active behaviour and have antimicrobial properties.

Actinomycetales↗
PubMed1992

Polypeptide profiles of normal and inflamed rabbit aqueous humor: identification of catabolic products of immunoglobulin G in the normal eye.

The anterior segment of the eye is isolated from the bloodstream by anatomic barriers. These barriers break down during inflammation elicited by muramyl dipeptide (MDP), a component of the cell walls of bacteria. The protein composition of normal aqueous humor and inflamed aqueous were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. The presence of transferrin, albumin, IgG and IgM were demonstrated in normal and inflamed aqueous. Normal aqueous additionally contained seven polypeptides (35, 31, 29, 25, 22, 21 and 19 kDa, respectively) that were not observed in inflamed aqueous. Four of these peptides (31, 29, 25 and 19 kDa) were identified as fragments of IgG heavy chains based on their reactivity with anti-IgG antibodies and staphylococcal protein A. Immunoglobulin catabolism has been noted to occur in tissues diffusely throughout the body; this is the first report of it occurring in the eye. This phenomenon appears to be circumvented on breakdown of the blood-aqueous barrier. These observations may relate to the immunoprivilege of the eye and its modulation in inflammation.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed2004

Temporal and spatial distribution of pectin epitopes in differentiating anthers and microspores of fertile and sterile sugar beet.

We studied the possible involvement of several pectin epitopes in anther differentiation and microsporogenesis in fertile and cytoplasmically male sterile sugar beets. The spatial and temporal distribution of five structural motifs were traced with a panel of monoclonal antibodies in six stages: premeiosis, meiotic prophase, young and mature tetrads, young and expanding microspores. The composition of the walls of sporogenous cells and meiocytes differed than that in the tapetum, as evidenced by the presence of alpha-Fuc(1-->2)-beta-Gal and alpha-(1-->5)-L-Ara epitopes binding CCRC-M1 and LM6 antibodies. At meiotic prophase, the meiocyte walls were additionally marked by the appearance of poorly methyl-esterified domains of homogalacturonan and of (1-->4)-beta-Gal residues, detected by JIM5 and LM5. Some constituents of the meiocyte wall which reacted with JIM5 and JIM7 persisted on the surface of the special callose sheath during tetrad development. In newly formed primexine and exine layers of tetrads and microspores, epitopes that were bound by JIM5, JIM7 and LM5 were abundant. No differences in the deposition or relative abundance of pectins were found between fertile and sterile anthers until microspore release from the callose. Later, at the time of abortion, sterile microspores had much larger amounts of epitopes detected by JIM5 than their fertile counterparts.

Antibodies, Monoclonal↗
PubMed1999

Protection against cancer by wheat bran: role of dietary fibre and phytochemicals.

Human intervention and animal studies have shown that supplementing the diet with wheat bran can protect against the development of a range of cancers, especially those of the colon and breast. Wheat bran is a rich source of dietary fibres (plant cell walls) that have structures and compositions which indicate that they may protect against cancer. Nevertheless, dietary fibre makes up less than half of wheat bran. Other nutrients and phytochemicals are present in wheat bran, some of which may also protect against cancer. These include phytic acid and various phenolic components such as phenolic acids, lignans and flavonoids. A major goal of future research on wheat bran should be to determine the relative roles in cancer prevention of the different components in wheat bran.

Animals↗
PubMed2003

Rhodoglobus vestalii gen. nov., sp. nov., a novel psychrophilic organism isolated from an Antarctic Dry Valley lake.

A novel, psychrophilic, gram-positive bacterium (designated strain LV3T) from a lake near the McMurdo Ice Shelf, Antarctica, has been isolated and characterized. This organism formed red-pigmented colonies, had an optimal growth temperature of 18 degrees C and grew on a variety of media between -2 and 21 degrees C. Scanning electron micrographs of strain LV3T that showed small rods with unusual bulbous protuberances during all phases of growth were of particular interest. The G + C content of the genomic DNA was approximately 62 mol%. The cell walls contained ornithine as the diamino acid. The major fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. Cells grown at -2 degrees C contained significant amounts of anteiso-C15:1. The major menaquinones found in strain LV3T were MK-11 and MK-12. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain LV3T was a member of the family Microbacteriaceae and related to, but distinct from, organisms belonging to the genera Agreia, Leifsonia and Subtercola. In addition, alignments of 16S rRNA sequences showed that the sequence of strain LV3T contained a 13 bp insertion that was found in only a few related sequences. Based on the low growth temperature, unusual cell shape, distinct 16S rRNA gene sequence and structure and cell-wall amino acid and menaquinone compositions, Rhodoglobus vestalii gen. nov., sp. nov. is proposed, with the type strain LV3T (= ATCC BAA-534T = CIP 107482T).

Actinomycetales↗