Nematic structuring of transparent and multifunctional nanocellulose papers

The nematic structuring of cellulose nanofibers (CNFs) is proposed as a nanostructural engineering tool for exploiting the potential of CNFs in conceptually new "transparent papers". The nematic-structured CNF papers exhibit superior mechanical properties, optical transparency, gas-barrier properties, heat transfer properties and electrical resistivity, compared with conventional randomly-structured CNF papers.

C-Terminal Identification of AD74, a Proteolytic Product ofEnterococcus faecalisAggregation Substance: Application of Liquid Chromatography/Mass Spectrometry

Sexual aggregation involved in conjugative transfer of Enterococcus faecalis plasmid pAD1 is enhanced by the sex pheromone cAD1, which is excreted from recipient cells. A membrane-anchored 137 kDa protein is a pAD1-encoded aggregation substance designated asal, which is responsible for cell-cell contact and leads to the aggregation of cells. An AD74 protein is a proteolytic product corresponding to the N-terminal half of asal. The C-terminal of AD74 was identified as lysine at position 510 (K-510) by liquid chromatography/mass spectrometry (LC/MS): it indicates that asal is cleaved specifically between K-510 and G-511.

Structural Elucidation of Minor Components of Peptidyl Antibiotic P168s (Leucinostatins) by Tandem Mass Spectrometry

Tandem mass spectrometry with a four-sector type mass spectrometer was used to elucidate the structures of minor components of the peptidyl antibiotic P168s (leucinostatins). As N-terminal fragments, ions by B-type cleavage were dominant, while V-type cleavages were observed along with X, Y, and Z types as C-terminal ions. The V-type ions were predominant in the cleavages of the amino terminals of leucyl and hydroxyleucyl residues. The structures of several minor components could be deduced from the tandem mass spectra.

Peptidal Sex Hormones Inducing Conjugation Tube Formation in Compatible Mating-Type Cells of Tremella mesenterica

The pair of peptidal sex hormones (tremerogen A-10 and tremerogen a-13) that induce conjugation tube formation in compatible type cells (A and a types) of Tremella mesenterica were isolated. Tremerogen A-10 is a dodecapeptide and tremerogen a-13, a tridecapeptide. In both peptides, the sulfiydryl group of the cysteines at the carboxyl terminus was blocked by farnesyl moieties.

Amino acid sequence of a prothoracicotropic hormone of the silkworm Bombyx mori

We have determined the complete amino acid sequence of 4K-PTTH-II, one of three forms of the M(r) 4400 prothoracicotropic hormone of the silkworm Bombyx mori, active to brainless pupae of Samia cynthia ricini. Like vertebrate insulin, it consists of two nonidentical peptide chains (A and B chains). The A chain consists of 20 amino acid residues. The B chain is a mixture of four microheterogeneous peptides, two of which consist of 28 residues, and the other two, of 26 residues. 4K-PTTH-II has considerable sequence homology (40%) with human insulin, and it resembles porcine relaxin both in the carboxyl-terminal cysteine residue of the A chain and in the amino-terminal pyroglutamic acid residue of the B chain. The identical distribution of the six cysteine residues also indicates that 4K-PTTH-II belongs to the insulin family.

The S haplotypes lacking SLG in the genome of Brassica rapa

Self-incompatibility (SI) discriminating self- and non-self pollen is regulated by S-locus genes in Brassica. In most of the S haplotypes, a highly polymorphic S-locus glycoprotein ( SLG) gene is tightly linked to genes for the SI determinants, S-receptor kinase ( SRK) and SP11, although the precise function of SLG in SI has not been clarified. In the present study, we performed DNA gel blot analysis for S(32), S(33), and S(36) haplotypes of Brassica rapa showing normal SI phenotypes and concluded that there might be no SLG in their genome. RNA gel blot analysis of the SLG-less S haplotypes indicated the possible existence of eSRK transcripts in the stigma. These three S haplotypes are useful resources to discern the molecular mechanism of the SI reaction without SLG.

Daily use of dentifrice with and without xylitol and fluoride: effect on glucose retention in humans in vivo

The effect of daily use of three different dentifrices on glucose retention after glucose mouth rinsing was tested in this study regarding xylitol and fluoride. Six experimental groups used three different dentifrices produced by two different companies: xylitol- and fluoride-containing dentifrice (XF), non-xylitol- and fluoride-containing dentifrice (F), and non-xylitol- and non-fluoride-containing dentifrice (NonX-NonF). Subjects were divided at random and rinsed their mouths for 15s with 20ml of 0.5M glucose solution. Glucose and lactate retention were determined by collecting samples of saliva from the approximal areas of the maxillary and mandibular anterior teeth and using the enzyme membrane test. Samples were collected 0, 1 and 2 months after the start of regular dentifrice use. There were significant differences in glucose retention in relation to the dentifrice used, month of sampling, site of sampling, and time since start of rinsing. Their contribution ratios were 2.0, 4.4, 11.7 and 7.4%, respectively (P<0.01). There were significant differences observed between the XF and NonX-NonF groups, with the XF group presenting lower glucose retention than the NonX-NonF group. The XF group presented lower glucose retention than the F group. The F group showed lower glucose retention than the NonX-NonF group. There were significant differences in lactate retention in relation to the month and site of sampling, and their contribution ratios were 3.3 and 2.8%, respectively (P<0.01). There were, however, no significant differences in glucose and lactate retention in relation to the dentifrice manufacturer. It was concluded that the XF dentifrice was the most effective, and the F dentifrice was more effective in reducing glucose retention than the NonX-NonF dentifrice.

Characterization of expressed genes in the SLL2 region of self-compatible Arabidopsis thaliana

Self-incompatibility in Brassica species is regulated by a set of S-locus genes: SLG, SRK, and SP11/SCR. In the vicinity of the S-locus genes, several expressed genes, SLL2 and SP2/ClpP, etc., were identified in B. campestris. Arabidopsis thaliana is a self-compatible Brassica relative, and its complete genome has been sequenced. From comparison of the genomic sequences between B. campestris and A. thaliana, microsynteny between gene clusters of Arabidopsis and Brassica SLL2 regions was observed, though the S-locus genes, SLG, SRK, and SP11/SCR were not found in the region of Arabidopsis. Almost all genes predicted in this region of Arabidopsis were expressed in both vegetative and reproductive organs, suggesting that the genes in the SLL2 region might not be related to self-incompatibility. Considering the recent speculation that the S-locus genes were translocated as a single unit between Arabidopsis and Brassica, the translocation might have occurred in the region between the SLL2 and SP7 genes.

Direct ligand-receptor complex interaction controls Brassica self-incompatibility

Many higher plants have evolved self-incompatibility mechanisms to prevent self-fertilization. In Brassica self-incompatibility, recognition between pollen and the stigma is controlled by the S locus, which contains three highly polymorphic genes: S-receptor kinase (SRK), S-locus protein 11 (SP11) (also called S-locus cysteine-rich protein; SCR) and S-locus glycoprotein (SLG). SRK encodes a membrane-spanning serine/threonine kinase that determines the S-haplotype specificity of the stigma, and SP11 encodes a small cysteine-rich protein that determines the S-haplotype specificity of pollen. SP11 is localized in the pollen coat. It is thought that, during self-pollination, SP11 is secreted from the pollen coat and interacts with its cognate SRK in the papilla cell of the stigma to elicit the self-incompatibility response. SLG is a secreted stigma protein that is highly homologous to the SRK extracellular domain. Although it is not required for S-haplotype specificity of the stigma, SLG enhances the self-incompatibility response; however, how this is accomplished remains controversial. Here we show that a single form of SP11 of the S8 haplotype (S8-SP11) stabilized with four intramolecular disulphide bonds specifically binds the stigma membrane of the S8 haplotype to induce autophosphorylation of SRK8, and that SRK8 and SLG8 together form a high-affinity receptor complex for S8-SP11 on the stigma membrane.

Dual targeting of spinach protoporphyrinogen oxidase II to mitochondria and chloroplasts by alternative use of two in-frame initiation codons

Protoporphyrinogen oxidase (Protox) is the final enzyme in the common pathway of chlorophyll and heme biosynthesis. Two Protox isoenzymes have been described in tobacco, a plastidic and a mitochondrial form. We isolated and sequenced spinach Protox cDNA, which encodes a homolog of tobacco mitochondrial Protox (Protox II). Alignment of the deduced amino acid sequence between Protox II and other tobacco mitochondrial Protox homologs revealed a 26-amino acid N-terminal extension unique to the spinach enzyme. Immunoblot analysis of spinach leaf extract detected two proteins with apparent molecular masses of 57 and 55 kDa in chloroplasts and mitochondria, respectively. In vitro translation experiments indicated that two translation products (59 and 55 kDa) are produced from Protox II mRNA, using two in-frame initiation codons. Transport experiments using green fluorescent protein-fused Protox II suggested that the larger and smaller translation products (Protox IIL and IIS) target exclusively to chloroplasts and mitochondria, respectively.

Sequence comparisons among dispersed members of the Brassica S multigene family in an S9 genome

Self-incompatibility (SI) systems prevent self-pollination and promote outbreeding. In Brassica, the SI genes SLG (for S-locus glycoprotein) and SRK (for S-receptor kinase) are members of the S multigene family, which share the SLG-like domain (S domain), which encodes a putative receptor. We have cloned members of the S multigene family from the S9 haplotype of B. campestris (syn. rapa). In addition, eight distinct genomic regions harboring 10 SLG/SRK-like genes were characterized in the present study. Sequence analysis revealed two novel SRK-like genes, BcRK3 and BcRK6 (for B. campestris receptor kinases 3 and 6, respectively). Other genes that were characterized included SFR2 (for S gene family receptor 2), SLR2 (for S locus related gene 2), and a pseudogene. Based on phylogenetic analysis of the nucleotide sequences of the S domain regions, SLG and SRK appear to be distinct from other members of the S multigene family. Linkage analysis showed that most members of the S multigene family are dispersed in the Brassica genome, and that SLR1 (S locus related gene 1) is not linked to the SLR2 in B. campestris.

The S receptor kinase gene determines dominance relationships in stigma expression of self-incompatibility in Brassica

Self-incompatibility (SI) in Brassica is sporophytically controlled by the multi-allelic S locus. SI phenotypes of the stigma and pollen in an S heterozygote are determined by the two S haplotypes it carries; the two haplotypes may be co-dominant or exhibit a dominant/recessive relationship. Because the S receptor kinase (SRK) gene of the S locus was recently shown to determine the S haplotype specificity of the stigma, we wished to investigate whether SRK also plays a role in the dominance relationships between S haplotypes. We crossed plants carrying an SRK28 transgene with plants homozygous for one of five S haplotypes that are either co-dominant with, or recessive to, S28 haplotype in the stigma, and analyzed the SI phenotypes of the progeny. In all cases, the SI phenotype of the stigma of plants carrying the SRK28 transgene could be predicted by the known dominance relationships between the S haplotype(s) and the S28 haplotype. Moreover, in the S43 homozygote carrying the SRK28 transgene where the S43 phenotype in the stigma was masked by the presence of the SRK28, the transcript level of SRK28 was found to be much lower than that of SRK43. All these results suggest that the dominance relationships between S haplotypes in the stigma are determined by SRK, but not by virtue of its relative expression level.

A pollen coat protein, SP11/SCR, determines the pollen S-specificity in the self-incompatibility of Brassica species

Many flowering plants have evolved self-incompatibility (SI) systems to prevent inbreeding. In the Brassicaceae, SI is genetically controlled by a single polymorphic locus, termed the S-locus. Pollen rejection occurs when stigma and pollen share the same S-haplotype. Recognition of S-haplotype specificity has recently been shown to involve at least two S-locus genes, S-receptor kinase (SRK) and S-locus protein 11 or S-locus Cys-rich (SP11/SCR). SRK encodes a polymorphic membrane-spanning protein kinase, which is the sole female determinant of the S-haplotype specificity. SP11/SCR encodes a highly polymorphic Cys-rich small basic protein specifically expressed in the anther tapetum and in pollen. In cauliflower (B. oleracea), the gain-of-function approach has demonstrated that an allele of SP11/SCR encodes the male determinant of S-specificity. Here we examined the function of two alleles of SP11/SCR of B. rapa by the same approach and further established that SP11/SCR is the sole male determinant of SI in the genus Brassica sp. Our results also suggested that the 522-bp 5'-upstream region of the S9-SP11 gene used to drive the transgene contained all the regulatory elements required for the unique sporophytic/gametophytic expression observed for the native SP11 gene. Promoter deletion analyses suggested that the highly conserved 192-bp upstream region was sufficient for driving this unique expression. Furthermore, immunohistochemical analyses revealed that the protein product of the SP11 transgene was present in the tapetum and pollen, and that in pollen of late developmental stages, the SP11 protein was mainly localized in the pollen coat, a finding consistent with its expected biological role.

Use of fluoridated dentifrice and glucose retention at the approximal areas of anterior teeth

The present study was undertaken to learn to what extent the use of dentifrice with fluoride affected glucose retention after glucose rinsing. Fifty-eight subjects consisting of forty male adults and eighteen female adults whose average age was 21.9 years were divided at random into two groups; one group used fluoridated dentifrice and the other group used nonfluoridated dentifrice. Subjects rinsed their mouths for fifteen seconds with 20 mL of 0.5 M glucose solution. Samples of saliva were taken from the approximal areas between the right and left central incisors of the maxilla and mandible by inserting the tip portion of a paper point three-minutes after the glucose rinsing, sample of saliva were taken from the neighboring approximal areas of the left central and left lateral incisors. Glucose content of the paper points was determined using the enzyme membrane method. Determinations were made before and at the end of the first, third, and fifth month over a five-month period. Fluoride concentrations in the resting saliva were also determined in different months during this period. At three-minutes and six-minutes, glucose retention in the group using fluoridated dentifrice was found to decrease slightly throughout the experiment; while glucose retention in the group on nonfluoridated dentifrice leveled off or increased in the fifth month. Fluoride concentration in the resting saliva increased during the experiment in the group using fluoridated dentifrice; while fluoride concentration in the group using nonfluoridated dentifrice did not change. It was concluded that the regular use of fluoridated dentifrice made glucose retention slightly lower and fluoride level in whole saliva higher.

Blasticidin A as an inhibitor of aflatoxin production by Aspergillus parasiticus

Blasticidin A, an antibiotic, showed strong inhibitory activity toward aflatoxin production by Aspergillus parasiticus. Its structure was characterized by NMR and chemical degradation experiments as 1, which is a tetramic acid derivative with a highly oxygenated long alkyl chain similar to aflastatin A (2). Absolute configurations of the eight chiral centers at C-4, 6, 31, 32, 33, 34, 35 and 37 of 1 were chemically determined. Blasticidin A almost completely inhibited aflatoxin production at 0.5 microM.

Flagellin from an incompatible strain of Pseudomonas avenae induces a resistance response in cultured rice cells

The host range of Pseudomonas avenae is wide among monocotyledonous plants, but individual strains can infect only one or a few host species. The resistance response of rice cells to pathogens has been previously shown to be induced by a rice-incompatible strain, N1141, but not by a rice-compatible strain, H8301. To clarify the molecular mechanism of the host specificity in P. avenae, a strain-specific antibody that was raised against N1141 cells and then absorbed with H8301 cells was prepared. When a cell extract of strain N1141 was separated by SDS-polyacrylamide gel electrophoresis and immunostained with the N1141 strain-specific antibody, only a flagellin protein was detected. Purified N1141 flagellin induced the hypersensitive cell death in cultured rice cells within 6 h of treatment, whereas the H8301 flagellin did not. The hypersensitive cell death could be blocked by pretreatment with anti-N1141 flagellin antibody. Furthermore, a flagellin-deficient N1141 strain lost not only the induction ability of hypersensitive cell death but also the expression ability of the EL2 gene, which is thought to be one of the defense-related genes. These results demonstrated that the resistance response in cultured rice cells is induced by the flagellin existing in the incompatible strain of P. avenae but not in the flagellin of the compatible strain.