Search results for "Peptidase"
showing 10 items of 567 documents
Function of Dipeptidyl Peptidase IV (CD26, Tp103) in Transfected Human T Cells
1993
CD26 (Tp103) is a proteolytic enzyme (dipeptidyl peptidase IV) expressed on the T cell surface that defines an alternative activation signal for human T lymphocytes. It is absent from or present in only low amounts on resting T cells but it is expressed strongly after activation. Crosslinking of CD26/Tp103 via the monoclonal antibody CB.1 triggers functional activities in preactivated T cells. To study the molecular requirements for T cell activation via CD26 we transfected a cDNA encoding CD26 into several CD26-negative cells. In Jurkat T cell leukemia cells that normally do not express the CD26 antigen, the transfected CD26 molecule is functional because the monoclonal antibody CB.1 induc…
Role of the virulence plasmid pR99 and the metalloprotease Vvp in resistance of Vibrio vulnificus serovar E to eel innate immunity
2007
Vibrio vulnificus biotype 2 serovar E (VSE) is a bacterial pathogen that produces a haemorrhagic septicaemia called vibriosis in eels. Its ability to grow in blood is conferred by a recently described virulence plasmid [Lee CT, Amaro C, Wu KM, Valiente E, Chang YF, Tsai SF, et al. A common virulence plasmid in biotype 2 Vibrio vulnificus and its dissemination aided by a conjugal plasmid. Journal of Bacteriology, submitted for publication.]. In this study, we analyzed the role of this plasmid together with the role played by the metalloprotease (Vvp) in the interaction between bacteria and eel innate immunity. To this end, we compared and statistically analyzed the differences in resistance …
Exploiting the Pleiotropic Antioxidant Effects of Established Drugs in Cardiovascular Disease.
2015
Cardiovascular disease is a leading cause of death and reduced quality of life worldwide. Arterial vessels are a primary target for endothelial dysfunction and atherosclerosis, which is accompanied or even driven by increased oxidative stress. Recent research in this field identified different sources of reactive oxygen and nitrogen species contributing to the pathogenesis of endothelial dysfunction. According to lessons from the past, improvement of endothelial function and prevention of cardiovascular disease by systemic, unspecific, oral antioxidant therapy are obviously too simplistic an approach. Source- and cell organelle-specific antioxidants as well as activators of intrinsic antiox…
Effects of PCSK9 variants on common carotid artery intima media thickness and relation to ApoE alleles.
2009
BACKGROUND: PCSK9 plays a key role in plasma cholesterol metabolism by modulating the expression of LDL receptors. OBJECTIVE AND METHODS: In this study we investigated the effects of two common polymorphism of the PCSK9 gene (E670G and I474V) on the intima media thickness of the common carotid artery and the possible relation with polymorphisms of apolipoprotein E in 1541 middle aged subjects selected from the general population enrolled in the PLIC study and confirmed the major findings in a second free-living population enrolled in the Ventimiglia study. RESULTS: 670G carriers showed significantly increased plasma total cholesterol, LDL-cholesterol, and Apo levels B while no significant d…
Reduced VLDL clearance in ApoeNpc1 mice is associated with increased Pcsk9 and Idol expression and decreased hepatic LDL-receptor levels
2010
Niemann-Pick type C1 (NPC1) promotes the transport of LDL receptor (LDL-R)-derived cholesterol from late endosomes/lysosomes to other cellular compartments. NPC1-deficient cells showed impaired regulation of liver_X receptor (LXR) and sterol regulatory element-binding protein (SREBP) target genes. We observed that Apoe(-/-)Npc1(-/-) mice displayed a marked increase in total plasma cholesterol mainly due to increased VLDL, reflecting decreased clearance. Although nuclear SREBP-2 and Ldlr mRNA levels were increased in Apoe(-/-)Npc1(-/-) liver, LDL-R protein levels were decreased in association with marked induction of proprotein convertase subtilisin/kexin type 9 (Pcsk9) and inducible degrade…
Protease A activity and nitrogen fractions released during alcoholic fermentation and autolysis in enological conditions
2000
Determination of protease A activity during alcoholic fermentation of a synthetic must (pH 3.5 at 25 degrees C) and during autolysis showed that a sixfold induction of protease A activity occurred after sugar exhaustion, well before 100% cell death occurred. A decrease in protease A activity was observed when yeast cell autolysis started. Extracellular protease A activity was detected late in the autolysis process, which suggests that protease A is not easily released. Evolution of amino acids and peptides was determined during alcoholic fermentation and during autolysis. Amino acids were released in early stationary phase. These amino acids were subsequently assimilated during the fermenta…
Protein quality control during aging involves recruitment of the macroautophagy pathway by BAG3.
2009
The Hsc/Hsp70 co-chaperones of the BAG (Bcl-2-associated athanogene) protein family are modulators of protein quality control. We examined the specific roles of BAG1 and BAG3 in protein degradation during the aging process. We show that BAG1 and BAG3 regulate proteasomal and macroautophagic pathways, respectively, for the degradation of polyubiquitinated proteins. Moreover, using models of cellular aging, we find that a switch from BAG1 to BAG3 determines that aged cells use more intensively the macroautophagic system for turnover of polyubiquitinated proteins. This increased macroautophagic flux is regulated by BAG3 in concert with the ubiquitin-binding protein p62/SQSTM1. The BAG3/BAG1 ra…
The Extracellular Vesicles of the Helminth Pathogen, Fasciola hepatica : Biogenesis Pathways and Cargo Molecules Involved in Parasite Pathogenesis
2015
Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterisation of the total secretome of this zoonotic parasite. Fasciola secretes at least two sub-populations of EVs that differ according to size, cargo molecules and site of release from the parasite. The larger EVs are released from the specialised cells that line the parasite gastrodermus and contain the zymogen of the 37 kDa cathepsin L peptidase that performs a digestive function. The smaller exosome-like vesicle population originate from multivesicular bodies with…
Mutation of the important Tyr-33 residue of chicken avidin: functional and structural consequences
2002
The strong interaction between avidin and biotin is so tight (dissociation constant 10-15M) that conditions usually sufficient for protein denaturing fail to dislodge biotin from the avidin—biotin complex. This kind of irreversible binding hinders the use of avidin in applications such as affinity purification or protein immobilization. To address this concern, we have constructed a series of mutants of the strategically positioned Tyr-33 in order to study the role of this residue in biotin binding, and to create avidin variants with more reversible ligand-binding properties. Unexpectedly, an avidin mutant in which Tyr-33 was replaced with phenylalanine (Avm-Y33F) displayed similar biotin-b…
EVOO's Effects on Incretin Production: Is There a Rationale for a Combination in T2DM Therapy?
2022
Type 2 diabetes mellitus (T2DM) is a serious public health concern as it is one of the most common chronic diseases worldwide due to social and economic developments that have led to unhealthy lifestyles, with a considerable impact both in terms of morbidity and mortality. The management of T2DM, before starting specific therapies, includes cornerstones such as healthy eating, regular exercise and weight loss. Strict adherence to the Mediterranean diet (MedDiet) has been related to an inverse association with the risk of T2DM onset, as well as an improvement in glycaemic control; in particular, thanks to the consumption of extra virgin olive oil (EVOO). Agonists of gut-derived glucagon-like…