The complexation behaviour of dithiocarbamate functions supported on polyacrylamides with varying extents (2-20 mol YO) of 4”-methylene-bisacrylamide (NNMBA) crosslinks was investigated. The crosslinked polyacrylamides were prepared by the free radical solution polymerization of the mononicrs in water at 80°C using potassium persulphate as initiator. The dithiocarbamate ligands were introduced ...

An important step ensuring the fidelity in protein biosynthesis is the aminoacylation of tRNAs by aminoacyl-tRNA synthetases. The accuracy of this process rests on a family of 20 enzymes, one for each amino acid. One exception is the formation of Gln-tRNA(Gln) that can be accomplished by two different pathways: aminoacylation of tRNA(Gln) with Gln by glutaminyl-tRNA synthetase (GlnRS; EC 6.1.1....

Glyoxalase 1 (GlxI) is the key enzyme that converts the highly reactive α-oxo-aldehydes into the corresponding α-hydroxy acids using l-glutathione as a cofactor. In our preliminary data, GlxI was identified as a substrate of transglutaminase 2 (TG2), a ubiquitous enzyme with multiple functions. According to the catalytic properties of TG2, protein cross-linking, polyamine conjugation, and/or de...

Transglutaminase2 (TGase2) activates Rho-associated kinase (ROCK), an important mediator of ischemia-reperfusion (IR) injury, through polyamination of RhoA. Cystamine, an oxidized dimer of cysteamine inhibits the transamidation activity of TGase2. We examined whether addition of cystamine to an organ preservation solution protects rat cardiomyocyte cells (H9C2) from cell death in IR injury. H9C...

C-peptide is a bioactive peptide with a potentially protective role in diabetes complications; however, its molecular mechanism of protection against cardiovascular damage caused by hyperglycemia-induced apoptosis remains unclear. We investigated the protective mechanism of C-peptide against hyperglycemia-induced apoptosis using human umbilical vein endothelial cells and streptozotocin diabetic...

Glutaminyl-tRNA synthetase is thought to be absent from organelles. Instead, Gln-tRNA is formed via the transamidation pathway, the other route to this essential compound in protein biosynthesis. However, it was previously shown that glutaminyl-tRNA synthetase activity is present in Leishmania mitochondria. This work identifies genes encoding glutaminyl- and glutamyl-tRNA synthetase in the clos...

Transglutaminase 3 (TGase 3) is a member of a family of Ca2+-dependent enzymes that catalyze covalent cross-linking reactions between proteins or peptides. TGase 3 isoform is widely expressed and is important for effective epithelial barrier formation in the assembly of the cell envelope. Among the nine TGase enzyme isoforms known in the human genome, only TGase 2 is known to bind and hydrolyze...

Four out of the 22 aminoacyl-tRNAs (aa-tRNAs) are systematically or alternatively synthesized by an indirect, two-step route requiring an initial mischarging of the tRNA followed by tRNA-dependent conversion of the non-cognate amino acid. During tRNA-dependent asparagine formation, tRNA(Asn) promotes assembly of a ribonucleoprotein particle called transamidosome that allows channelling of the a...

Neurodegeneration in diseases caused by altered metabolism of mammalian prion protein (PrP) can be averted by reducing PrP expression. To identify novel pathways for PrP downregulation, we analyzed cells that had adapted to the negative selection pressure of stable overexpression of a disease-causing PrP mutant. A mutant cell line was isolated that selectively and quantitatively routes wild typ...

We showed previously that transdifferentiation of skin epidermis to mucous epithelium can be induced by treatment with 20 µM retinol for 1 d followed by culture for 4 d without retinol in chick embryonic tarsometatarsal skin. In mouse epidermal cells, 3 µM retinoic acid (an active metabolite of retinol) inhibits epidermal keratinization in consistent with an increase in transglutaminase (TG)2/G...