The cleavage of C−O linkages in aryl ethers biomass-derived lignin compounds without hydrogenation the aromatic rings is a major challenge for production sustainable mono-aromatics. Conventional strategies over heterogeneous metal catalysts require addition homogeneous base additives causing environmental problems. Herein, we propose Ru/C catalyst modified by Br atoms selective direct bonds dip...

Signal peptidase cleavage at the C-prM junction in the flavivirus structural polyprotein is inefficient in the absence of the cytoplasmic viral protease, which catalyzes cleavage at the COOH terminus of the C protein. The signal peptidase cleavage occurs efficiently in circumstances where the C protein is deleted or if the viral protease complex is present. In this study, we used cDNA of Murray...

Herein we report the mechanism of human acid ceramidase (AC; N-acylsphingosine deacylase) cleavage and activation. A highly purified, recombinant human AC precursor underwent self-cleavage into alpha and beta subunits, similar to other members of the N-terminal nucleophile hydrolase superfamily. This reaction proceeded with first order kinetics, characteristic of self-cleavage. AC self-cleavage...

At the 64-cell-stage embryos of Patella develop a prototroch consisting of four groups of four cilia-bearing cells. Ciliogenesis of isolated blastomeres and trochoblasts was studied, as well as the effect on it of cleavage arrest caused by cytochalasin B treatment. Isolation of blastomeres or trochoblast cells has no influence on ciliogenesis; neither has arrest of cleavage in whole embryos aft...

Several major alliances of metazoan phyla have been identified by small subunit rRNA sequence comparisons. It is possible to arrange the phyla to produce a parsimonious distribution of cleavage types, requiring only one change from a radial ancestral condition to spiral cleavage and one other to "idiosyncratic" cleavage; this arrangement is consistent with most of the recent molecular phylogeni...

Truncated versions of the human cytomegalovirus (CMV) strain Towne glycoprotein B (gB) gene were stably expressed in CHO cell lines. The calcium-specific ionophore A23187 inhibited proteolytic cleavage of C-terminal-truncated gB expressed by cell line 67.77. These inhibition studies also showed that the 93-kilodalton cleavage product most likely represents the N-terminal cleavage fragment of gB...

Of the various theories that have been advanced to account for the mechanism of furrow formation and cytokinesis in animal cells (9, 21), the notion of active constriction in the equatorial cortex has recently received support from physical measurements such as those reported by Wolpert (22) and Rappaport (13) . A probable structural manifestation of the "contractile ring" has been found throug...

A large protein machinery is required for 3'-end processing of mRNA precursors in eukaryotes. Cleavage factor IA (CF IA), a complex in the 3'-end processing machinery in yeast, contains four subunits, Rna14, Rna15, Clp1, and Pcf11. Rna14 has a HAT (half a TPR) domain at the N terminus and a region at the C terminus that mediates interactions with Rna15. Rna15 contains a RNA recognition module (...

An efficient system has been developed for the reproducible regeneration of plants from cell suspension-derived protoplasts of the two commercial Iranian Japonica rice cultivars Tarom and Khazer. Friable embryogenic calli were used for cell suspension initiation and protoplasts were isolated from both varieties. When embedded in agarose, protoplasts failed to divide. However, sustained division...

We have analysed the DNA cleavage reaction of DNA gyrase using oligonucleotides annealed to a single-stranded M13 derivative containing a preferred gyrase cleavage site. We find that gyrase can cleave duplexes down to approximately 20 bp in size in the presence of the quinolone drugs ciprofloxacin and oxolinic acid. Ciprofloxacin shows a variation in its site specificity with an apparent prefer...