Design,synthesis and evaluation of curcumin-based fluorescent probes to detect Aβ fibrils

Amyloid β fibrillation is an early event in Alzheimer’s disease, so its detection is important to understand its roles in Alzheimer’s disease. Curcumin, which has poor water solubility, has been reported to have many pharmacological activities including potent anti-amyloid β fibril activity in Alzheimer’s disease. In this study, we found that curcumin analogues with the fluorescence property instead of non-inhibition of amyloid β fibrils. The development of new curcumin analogue, Me-CUR (9), as fluorescent switchable probe to detect amyloid β fibrils is described. Me-CUR (9) shows excellent fluorescence, especially higher than ThT (4), in the presence of amyloid β fibrils. These results suggest that Me-CUR (9) can become a useful in vitro amyloid fluorescence sensor for diagnosis of Alzheimer’s disease.     

Class I HLA antigens in two long-separated populations: Melanesians and South Amerinds

Class I HLA antigens have been compared in 5,835 Melanesians of Papua New Guinea and 2,028 Amerindians of South America. The sample includes 50 PNGMel ethnolinguistic groups and 22 SAmlnd groups. Both carry 15 serologically defined antigens and an undefined C allele. Except for A2 in Papua New Guinea and Cwl in South America, these antigens are widely distributed in their respective populations. Nine (A2 and A24, B39, B60 and B62, and Cwl, Cw3, Cw4, and Cw7) are common to both. This commonality suggests that these two populations derive from an ancestral population with less polymorphism than modern East Asians. In both populations several theoretically possible haplotypes were absent, and other haplo-types were in positive disequilibrium in both. The parallels in disequilibria suggest that haplotypes are subject to selective forces acting on the level of allelic interaction. Based on three locus haplotype frequencies, the PNGMel groups form five clusters with internally typical linguistic and geographic characteristics and a miscellaneous category, but Samlnd groups show no cluster. © 1995 Wiley-Liss, Inc.     

Construction of new excretion vectors: two and three tandemly located promoters are active for extracellular protein production from Escherichia coli

Summary In order to develop a more useful system for extracellular protein production from Escherichia coli, we have constructed the new excretion vectors pEAP82-1, pEAP82-2, and pEAP82-3. These vectors have, respectively, a single, double, and triple penicillinase promoter upstream of a penicillinase structural gene; E. coli HB101 carrying pEAP82-2 or pEAP82-3 produced respectively, about twice or three times as much penicillinase protein than that produced by E. coli carrying pEAP82-1, and 70% to 80% of the protein was excreted into the culture medium. The E. coli carrying pEAP82-3 was cultivated at various temperatures and it was observed that the optimum for extracellular penicillinase production was 30°–37°C. Using this multi-promoter excretion system, the amount of extracellular production of human growth hormone was increased by several fold as observed with penicillinase excretion.     

Family resemblance for glucose tolerance in a Melanesian population, the Tolai

Path analysis of family resemblance for plasma glucose concentration, 2 h after an oral glucose challenge, failed to detect significant genetic heritability. There were no intergenerational differences and marital resemblance was moderate. Over one-third of sibling environmental similarity was due to non-inherited factors. Cultural inheritance was very strong, tending to mimic genetic inheritance, and cultural heritability was considerable. Measures of obesity were included in the environmental index, an estimate of familial environment, in this analysis, for comparability with previous studies. Since obesity appears, in part, to be a heritable trait, in future studies a bivariate approach to family resemblance for both glucose tolerance and obesity could yield important additional insight.     

Microbial communities associated with geological horizons in coastal subseafloor sediments from the sea of okhotsk

Microbial communities from a subseafloor sediment core from the southwestern Sea of Okhotsk were evaluated by performing both cultivation-dependent and cultivation-independent (molecular) analyses. The core, which extended 58.1 m below the seafloor, was composed of pelagic clays with several volcanic ash layers containing fine pumice grains. Direct cell counting and quantitative PCR analysis of archaeal and bacterial 16S rRNA gene fragments indicated that the bacterial populations in the ash layers were approximately 2 to 10 times larger than those in the clays. Partial sequences of 1,210 rRNA gene clones revealed that there were qualitative differences in the microbial communities from the two different types of layers. Two phylogenetically distinct archaeal assemblages in the Crenarchaeota, the miscellaneous crenarchaeotic group and the deep-sea archaeal group, were the most predominant archaeal 16S rRNA gene components in the ash layers and the pelagic clays, respectively. Clones of 16S rRNA gene sequences from members of the gamma subclass of the class Proteobacteria dominated the ash layers, whereas sequences from members of the candidate division OP9 and the green nonsulfur bacteria dominated the pelagic clay environments. Molecular (16S rRNA gene sequence) analysis of 181 isolated colonies revealed that there was regional proliferation of viable heterotrophic mesophiles in the volcanic ash layers, along with some gram-positive bacteria and actinobacteria. The porous ash layers, which ranged in age from tens of thousands of years to hundreds of thousands of years, thus appear to be discrete microbial habitats within the coastal subseafloor clay sediment, which are capable of harboring microbial communities that are very distinct from the communities in the more abundant pelagic clays.     

Analysis of the Bacillus subtilis spoIIIJ gene and its Paralogue gene, yqjG

The Bacillus subtilis spoIIIJ gene, which has been proven to be vegetatively expressed, has also been implicated as a sporulation gene. Recent genome sequencing information in many organisms reveals that spoIIIJ and its paralogous gene, yqjG, are conserved from prokaryotes to humans. A homologue of SpoIIIJ/YqjG, the Escherichia coli YidC is involved in the insertion of membrane proteins into the lipid bilayer. On the basis of this similarity, it was proposed that the two homologues act as translocase for the membrane proteins. We studied the requirements for spoIIIJ and yqjG during vegetative growth and sporulation. In rich media, the growth of spoIIIJ and yqjG single mutants were the same as that of the wild type, whereas spoIIIJ yqjG double inactivation was lethal, indicating that together these B. subtilis translocase homologues play an important role in maintaining the viability of the cell. This result also suggests that SpoIIIJ and YqjG probably control significantly overlapping functions during vegetative growth. spoIIIJ mutations have already been established to block sporulation at stage III. In contrast, disruption of yqjG did not interfere with sporulation. We further show that high level expression of spoIIIJ during vegetative phase is dispensable for spore formation, but the sporulation-specific expression of spoIIIJ is necessary for efficient sporulation even at the basal level. Using green fluorescent protein reporter to monitor SpoIIIJ and YqjG localization, we found that the proteins localize at the cell membrane in vegetative cells and at the polar and engulfment septa in sporulating cells. This localization of SpoIIIJ at the sporulation-specific septa may be important for the role of spoIIIJ during sporulation.     

Tandem location of the cellulase genes on the chromosome of Bacillus sp. strain N-4

Abstract A 5.7-kb Eco RI DNA fragment has been isolated from Bacillus sp. strain N-4 chromosome DNA. This fragment contained both the pNK1-encoded cellulase ( celB ) gene and the pNK2-encoded cellulase ( celA ) gene which were highly homologous [13]. These results demonstrate the tandem location of these genes on the chromosomal DNA. The homologous sequence, which may play an important role for the gene duplication, were observed 5' upstream of the celA gene, between the celA and celB genes, and 3' downstream from the celB gene.