Novel Hybrid Catalysts of Cysteine Proteases Enhanced by Chitosan and Carboxymethyl Chitosan Micro- and Nanoparticles.

Micro- and nanoparticles of chitosan and carboxymethyl chitosan were synthesized, both with and without ascorbic acid. Methods were developed to form complexes between these micro- and nanoparticles and plant proteases-ficin, papain, and bromelain. It was demonstrated that the activity of cysteine protease complexes with carboxymethyl chitosan micro- and nanoparticles was higher compared to those with chitosan micro- and nanoparticles.

Fallopian Tube Hemangioma Discovered on Follow-up for Uterine Leiomyoma.

Hemangioma in female reproductive organs, particularly in the fallopian tube (FT), is a sporadic disease. In this report, we describe a case of hidden capillary hemangioma in FT in a 39-year-old woman who suffered from uterine leiomyoma. During the preoperative stage, pelvic sonography, computed tomography, and diagnostic laparoscopy revealed a subserous leiomyomatous nodule located along the posterior wall of the uterus.

Novel biocatalysts based on enzymes in complexes with nano- and micromaterials.

In today's world, there is a wide array of materials engineered at the nano- and microscale, with numerous applications attributed to these innovations. This review aims to provide a concise overview of how nano- and micromaterials are utilized for enzyme immobilization. Enzymes act as eco-friendly biocatalysts extensively used in various industries and medicine.

Novel Biocatalysts Based on Bromelain Immobilized on Functionalized Chitosans and Research on Their Structural Features.

Enzyme immobilization on various carriers represents an effective approach to improve their stability, reusability, and even change their catalytic properties. Here, we show the mechanism of interaction of cysteine protease bromelain with the water-soluble derivatives of chitosan-carboxymethylchitosan, -(2-hydroxypropyl)-3-trimethylammonium chitosan, chitosan sulfate, and chitosan acetate-during immobilization and characterize the structural features and catalytic properties of obtained complexes. Chitosan sulfate and carboxymethylchitosan form the highest number of hydrogen bonds with bromelain in comparison with chitosan acetate and -(2-hydroxypropyl)-3-trimethylammonium chitosan, leading to a higher yield of protein immobilization on chitosan sulfate and carboxymethylchitosan (up to 58 and 65%, respectively).

The Sole DEAD-Box RNA Helicase of the Gastric Pathogen Is Essential for Colonization.

Present in every kingdom of life, generally in multiple copies, DEAD-box RNA helicases are specialized enzymes that unwind RNA secondary structures. They play major roles in mRNA decay, ribosome biogenesis, and adaptation to cold temperatures. Most bacteria have multiple DEAD-box helicases that present both specialized and partially redundant functions.

RNase J depletion leads to massive changes in mRNA abundance in Helicobacter pylori.

Degradation of RNA as an intermediate message between genes and corresponding proteins is important for rapid attenuation of gene expression and maintenance of cellular homeostasis. This process is controlled by ribonucleases that have different target specificities. In the bacterial pathogen Helicobacter pylori, an exo- and endoribonuclease RNase J is essential for growth.

A minimal bacterial RNase J-based degradosome is associated with translating ribosomes.

Protein complexes directing messenger RNA (mRNA) degradation are present in all kingdoms of life. In Escherichia coli, mRNA degradation is performed by an RNA degradosome organized by the major ribonuclease RNase E. In bacteria lacking RNase E, the existence of a functional RNA degradosome is still an open question.

Maturation of 23S rRNA in Bacillus subtilis in the absence of Mini-III.

23S rRNA maturation in Bacillus subtilis is catalyzed by the recently characterized enzyme Mini-RNase-III. Mini-III is dispensable, however, and 23S rRNA is matured by other ribonucleases in strains lacking this enzyme. Here we show that these RNases are the 5'-to-3' exoribonuclease RNase J1 and the 3'-to-5' exoribonucleases, principally RNase PH and YhaM.

Assay of Bacillus subtilis ribonucleases in vitro.

Significant progress has been made recently regarding the identification of the ribonucleases involved in RNA maturation and degradation in Bacillus subtilis. More than half of these enzymes have no ortholog in Escherichia coli. To confirm that the in vivo effects of mutations in genes encoding RNases are direct, it is often necessary to purify the enzymes and assay their activity in vitro.

Ribosomal protein L3 bound to 23S precursor rRNA stimulates its maturation by Mini-III ribonuclease.

Ribosomal RNAs (rRNAs) are processed from larger primary transcripts in every living system known. The maturation of 23S rRNA in Bacillus subtilis is catalysed by Mini-III, a member of the RNase III family of enzymes that lacks the characteristic double-stranded RNA binding domain of its relatives. We have previously shown that Mini-III processing of 23S precursor rRNA in assembled 50S ribosomal subunits is much more efficient than a substrate with no ribosomal proteins bound, suggesting that one or more large subunit proteins act as a cofactor for Mini-III cleavage.

Mini-III, an unusual member of the RNase III family of enzymes, catalyses 23S ribosomal RNA maturation in B. subtilis.

The late steps of both 16S and 5S ribosomal RNA maturation in the Gram-positive bacterium Bacillus subtilis have been shown to be catalysed by ribonucleases that are not present in the Gram-negative paradigm, Escherichia coli. Here we present evidence that final maturation of the 5' and 3' extremities of B. subtilis 23S rRNA is also performed by an enzyme that is absent from the Proteobacteria.

An update on abscisic acid signaling in plants and more..

The mode of abscisic acid (ABA) action, and its relations to drought adaptive responses in particular, has been a captivating area of plant hormone research for much over a decade. The hormone triggers stomatal closure to limit water loss through transpiration, as well as mobilizes a battery of genes that presumably serve to protect the cells from the ensuing oxidative damage in prolonged stress. The signaling network orchestrating these various responses is, however, highly complex.

Lactococcus lactis gene yjgB encodes a gamma-D-glutaminyl-L-lysyl-endopeptidase which hydrolyzes peptidoglycan.

YjgB is one of five peptidoglycan hydrolases previously identified in Lactococcus lactis. Analysis of its amino acid sequence revealed that YjgB contains an NlpC/P60 domain, whereas no specific cell wall binding domain or motif could be identified. The NlpC/P60 family is characterized by three conserved residues, a cysteine, a histidine, and a polar residue.

When all's zed and done: the structure and function of RNase Z in prokaryotes.

RNase Z is a widely distributed and often essential endoribonuclease that is responsible for the maturation of the 3'-end of a large family of transfer RNAs (tRNAs). Although it has been the subject of study for more than 25 years, interest in this enzyme intensified dramatically with the identification of the encoding gene in 2002. This led to the discovery of RNase Z in bacteria, in which the final step in the generation of the mature 3'-end of tRNAs had previously been assumed to be catalysed by exoribonucleases.

Arabidopsis RNA-binding protein UBA2a relocalizes into nuclear speckles in response to abscisic acid.

The Arabidopsis thaliana RNA binding protein UBA2a is the closest homologue of the Vicia faba AKIP1 (56% identity). Like AKIP1, UBA2a is a constitutively-expressed nuclear protein and in response to ABA it is also reorganized within the nucleus in "speckles" suggesting a possible role of this protein in the regulation of mRNA metabolism during ABA signaling. AKIP1 interacts with, and is phosphorylated by, the upstream ABA-activated protein kinase AAPK.

"Zn-link": a metal-sharing interface that organizes the quaternary structure and catalytic site of the endoribonuclease, RNase E.

Ribonuclease E is an essential hydrolytic endonuclease in Escherichia coli, and it plays a central role in maintaining the balance and composition of the messenger RNA population. The enzyme is also required for rRNA and tRNA processing. We have shown earlier that the highly conserved catalytic domain of E.

Analysis of the peptidoglycan hydrolase complement of Lactococcus lactis: identification of a third N-acetylglucosaminidase, AcmC.

The peptidoglycan hydrolase (PGH) complement of Lactococcus lactis was identified by amino acid sequence similarity searching of the L. lactis IL-1403 complete genome sequence. Five PGHs that are not encoded by prophages were detected, including the previously characterized AcmA and AcmB proteins.

Quaternary structure and catalytic activity of the Escherichia coli ribonuclease E amino-terminal catalytic domain.

RNase E is an essential endoribonuclease that plays a central role in the processing and degradation of RNA in Escherichia coli and other bacteria. Most endoribonucleases have been shown to act distributively; however, Feng et al. [(2002) Proc.

Determination of the catalytic parameters of the N-terminal half of Escherichia coli ribonuclease E and the identification of critical functional groups in RNA substrates.

Ribonuclease E is required for the rapid decay and correct processing of RNA in Escherichia coli. A detailed understanding of the hydrolysis of RNA by this and related enzymes will require the integration of structural and molecular data with quantitative measurements of RNA hydrolysis. Therefore, an assay for RNaseE that can be set up to have relatively high throughput while being sensitive and quantitative will be advantageous.