Search results for "ENZYMES"
showing 10 items of 730 documents
Purification and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds.
2013
Aminopeptidases (EC 3.4.11) are proteolytic enzymes, which hydrolyze one amino acid from N-terminus of peptidic substrates. Inhibitors of plant aminopeptidases can find an application in agriculture as herbicides. Isolation and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds has been described. The enzyme was purified to molecular homogeneity using a six-step purification procedure (precipitation with (NH4)2SO4, followed by chromatography on Sephadex G-25, DEAE-Sepharose, Sephacryl HR 300, Macro-Prep Q and Phenyl-Sepharose HP columns). The enzyme was purified 365-fold with recovery above 18%. The molecular weight of the purified enzyme was determined by SDS…
Proteins in Ionic Liquids: Reactions, Applications, and Futures
2019
Biopolymer processing and handling is greatly facilitated by the use of ionic liquids, given the increased solubility, and in some cases, structural stability imparted to these molecules. Focussing on proteins, we highlight here not just the key drivers behind protein-ionic liquid interactions that facilitate these functionalities, but address relevant current and potential applications of protein-ionic liquid interactions, including areas of future interest.
Metabotropic glutamate receptors activate phospholipase D in astrocytes through a protein kinase C-dependent and Rho-independent pathway.
2003
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that mediate phospholipase D (PLD) activation in brain, but the mechanism underlying this response remains unclear. Here we used primary cultures of astrocytes as a cell model to explore the mechanism that links mGluRs to PLD. Glutamate activated both phospholipase C (PLC) and PLD with equal potency and this effect was mimicked by L-cysteinesulfinic acid, a putative neurotransmitter previously shown to activate mGluRs coupled to PLD, but not PLC, in adult brain. PLD activation by glutamate was dependent on Ca(2+) mobilization and fully blocked by both protein kinase C (PKC) inhibitors and PKC down-regulation, suggesti…
Influence of Degradative Enzymatic Activities on the Shelf Life of Ready-to-Eat Prickly Pear Fruits
2012
Prickly pear fruit (Opuntia ficus indica L. Miller) belongs to the Cactaceae family. This species is very sensitive to low storage temperatures (< 5°C) which cause damages. The fruits can be peeled, suitably packaged and successfully commercialized as a ready-to-eat product. The main limit to the extension of the shelf life is the production of off-flavors due to different factors, the growth of microorganisms and the action of endogenous enzymes. Lipoxygenase (LOX) and Pectinesterase (PE) are involved in fruit degradation. In particular, LOX pathway is directly responsible for lipid oxidation, and the subsequent production of off-flavours, while PE causes the softening of fruit during m…
Primer estudio experimental sobre los efectos de la digestión en restos esqueléticos de murciélagos (Mammalia: Chiroptera)
2018
Taphonomic studies dealing with small mammals do not usually consider bats. Therefore, the degree to which bat bones are modi? ed by predation and other taphonomic agents are largely unknown. Here we present the results obtained from a set of experiments developed to approach this issue, focusing initially on the e?ect of digestion. For this purpose several bat bones and teeth were exposed to HCl and to two di?erent proteolithic enzymes. The experiments showed that bat bones are altered by acidic and enzymatic attack in a similar way as the bones of other small mammals. However, some patterns were observed in the teeth that had not been previously described in other groups. Thus, both the i…
Enzimas salivales y enfermedad periodontal
2006
Objetivos: Las enfermedades que producen daño tisular producen la liberación de diferentes enzimas relacionadas con la muerte y destrucción celular, como son la aspartato y alanino aminotransferasa (AST, ALT), lactato dehidrogenasa (LDH), creatinin kinasa (CK), alcalina y ácida (ALP, ACP) y gamma glutamil transferasa (GGT). Al tratarse la enfermedad periodontal (EP) de un proceso inflamatorio con afectación de la encía y periodonto, parece lógico pensar que la actividad enzimática debe reflejar los cambios metabólicos secundarios a esta reacción inflamatoria. Diseño del estudio: En este artículo examinamos la actividad de CK, LDH, AST, ALT, GGT, ALP y ACP en la saliva de pacientes con EP, a…
Functional characterization of the human tRNA methyltransferases TRMT10A and TRMT10B
2020
Abstract The TRM10 family of methyltransferases is responsible for the N1-methylation of purines at position 9 of tRNAs in Archaea and Eukarya. The human genome encodes three TRM10-type enzymes, of which only the mitochondrial TRMT10C was previously characterized in detail, whereas the functional significance of the two presumably nuclear enzymes TRMT10A and TRMT10B remained unexplained. Here we show that TRMT10A is m1G9-specific and methylates a subset of nuclear-encoded tRNAs, whilst TRMT10B is the first m1A9-specific tRNA methyltransferase found in eukaryotes and is responsible for the modification of a single nuclear-encoded tRNA. Furthermore, we show that the lack of G9 methylation cau…
Role of human metabolizing enzymes in food perception
2022
Flavor is the main factor determining food acceptability. Flavor corresponds to the combination of the signals from the gustatory system, the olfactory system and the trigeminal system. Interactions between proteins and flavor molecules in oral/nasal cavities are proposed to modulate flavor perception through a series of events knowns as perireceptor events. Among these proteins involved in this modulation are found enzymes mainly known for their role in the detoxification process. These enzymes are able to recognize a large panel of molecules. We proposed to explore the role of these enzymes in food perception. We demonstrated that enzymatic activities present in the oral epithelium and sa…
Characterization of the autoantigen La (SS-B) as a dsRNA unwinding enzyme
1997
During the analysis of the La (SS-B) autoantigen for catalytic activities an ATP-dependent double-stranded RNA unwinding activity was detected. Both native and recombinant La proteins from different species displayed this activity, which could be inhibited by monospecific anti-La antibodies. La protein was able to melt dsRNA substrates with either two 3'-overhangs or a single 3'- and a 5'-overhang. Double-stranded RNAs with two 5'-overhangs were not unwound, indicating that at least one 3'-overhang is required for unwinding. Sequence elements of the La protein that might be involved in dsRNA unwinding, such as an evolutionarily conserved putative ATP-binding motif and an element that is hom…