Search results for "Glutaminase"
showing 10 items of 78 documents
Monitoring of transglutaminase crosslinking reaction by 1H NMR spectroscopy on model substrates
2015
International audience; A new method based on 1H NMR spectroscopy was developed for monitoring transglutaminase crosslinking reaction with model molecules (CBZ-Gln-Gly and N-α-acetyl-lysine). The transglutaminase reaction led to the appearance of new resonances on NMR spectrum as well as significant decrease in others. The new observed resonances, originated from newly formed ɛ-(γ-glutamyl)lysine isopeptide bonds, evidence the enzymatic reaction and allow to quantify the ɛ-(γ-glutamyl)lysine fragment. Moreover, the decrease in resonance intensity, originated from lysine, permit to determine the crosslinking degree. These results obtained by 1H NMR spectroscopy can be used as an alternative …
Innovative food processing technologies on the transglutaminase functionality in protein-based food products: Trends, opportunities and drawbacks
2018
Abstract Background Consumption of protein-based food products has a key role in the improvement of human health. The crosslinking agent microbial transglutaminase (mTGase) is an effective and promising tool to modify animal proteins used in the food industry. Improvement in the gelation process, physicochemical and textural quality, and consumer's demand of protein-based food products could be attained by combining mTGase and some non-conventional food processing technologies. Scope and approach New perspectives and key areas for future research in the development of high-quality food proteins and protein-based products as a function of interaction effect of mTGase and some new processing …
Duodenal Bacteria From Patients With Celiac Disease and Healthy Subjects Distinctly Affect Gluten Breakdown and Immunogenicity
2016
Background & Aims Partially degraded gluten peptides from cereals trigger celiac disease (CD), an autoimmune enteropathy occurring in genetically susceptible persons. Susceptibility genes are necessary but not sufficient to induce CD, and additional environmental factors related to unfavorable alterations in the microbiota have been proposed. We investigated gluten metabolism by opportunistic pathogens and commensal duodenal bacteria and characterized the capacity of the produced peptides to activate gluten-specific T-cells from CD patients. Methods We colonized germ-free C57BL/6 mice with bacteria isolated from the small intestine of CD patients or healthy controls, selected for their in v…
β1-Integrin– and K(V)1.3 channel–dependent signaling stimulates glutamate release from Th17 cells
2020
Although the impact of Th17 cells on autoimmunity is undisputable, their pathogenic effector mechanism is still enigmatic. We discovered soluble N-ethylmaleimide–sensitive factor attachment receptor (SNARE) complex proteins in Th17 cells that enable a vesicular glutamate release pathway that induces local intracytoplasmic calcium release and subsequent damage in neurons. This pathway is glutamine dependent and triggered by binding of β1-integrin to vascular cell adhesion molecule 1 (VCAM-1) on neurons in the inflammatory context. Glutamate secretion could be blocked by inhibiting either glutaminase or K(V)1.3 channels, which are known to be linked to integrin expression and highly expressed…
Aβ Induces Excitotoxicity Mediated by APC/C-Cdh1 Depletion That Can Be Prevented by Glutaminase Inhibition Promoting Neuronal Survival
2016
AbstractThe E3 ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C) is activated by the fizzy-related protein homolog/CDC20-like protein 1 (cdh1) in post-mitotic neurons. Growing evidence suggests that dysregulation of APC/C-Cdh1 is involved in neurodegenerative diseases. Here we show in neurons that oligomers of amyloid beta (Aβ), a peptide related to Alzheimer’s disease, cause proteasome-dependent degradation of cdh1. This leads to a subsequent increase in glutaminase (a degradation target of APC/C-Cdh1), which causes an elevation of glutamate levels and further intraneuronal Ca2+ dysregulation, resulting in neuronal apoptosis. Glutaminase inhibition prevents glutamate excitotoxi…
Vascular ageing and endothelial cell senescence: Molecular mechanisms of physiology and diseases
2016
Ageing leads to a progressive deterioration of structure and function of all organs over the time. During this process endothelial cells undergo senescence and manifest significant changes in their properties, resulting in impairment of the vascular functionality and neo-angiogenic capability. This ageing-dependent impairment of endothelial functions is considered a key factor contributing to vascular dysfunctions, which is responsible of several age-related diseases of the vascular system and other organs. Several mechanisms have been described to control ageing-related endothelial cell senescence including microRNAs, mitochondrial dysfunction and micro environmental stressors, such as hyp…
The Candida albicans ENO1 gene encodes a transglutaminase involved in growth, cell division, morphogenesis, and osmotic protection
2018
Candida albicans is an opportunistic fungus that is part of the normal microflora commonly found in the human digestive tract and the normal mucosa or skin of healthy individuals. However, in immunocompromised individuals, it becomes a serious health concern and a threat to their lives and is ranked as the leading fungal infection in humans worldwide. As existing treatments for this infection are non-specific or under threat of developing resistance, there is a dire necessity to find new targets for designing specific drugs to defeat this fungus. Some authors reported the presence of the transglutaminase activity in Candida and Saccharomyces, but its identity remains unknown. We report here…
Celiac disease and endocrine autoimmunity - the genetic link.
2018
Celiac disease is a small intestinal inflammatory disease with autoimmune features that is triggered and maintained by the ingestion of the storage proteins (gluten) of wheat, barley and rye. The prevalence of celiac disease is increased in patients with monoglandular and/or polyglandular autoimmunity and their relatives. Between 10 and 30% of patients with celiac disease are thyroid and/or type 1 diabetes antibody positive, while around 5 to 7% of patients with autoimmune thyroid disease and/or type 1 diabetes are IgA anti-tissue transglutaminase antibody positive. The close relationship between celiac disease and endocrine autoimmunity is largely explained by sharing a common genetic back…
Adherence to dietary treatment and clinical factors associated with anti-transglutaminase antibodies in celiac disease during the follow-up
2021
Introduction In clinical practice, celiac disease (CD) is monitored through anti-transglutaminase (TGA-IgA) antibody levels. The normalization of serum levels in successive periodic measurements indicates good response and adherence to dietary treatment. Objectives To evaluate the factors associated with the evolution of TGA-IgA antibodies and their association with dietary non-compliance and diseases related to CD. Methods This prospective observational study was carried out in 254 participants, who were recruited from patients from a hospital in southern Spain. Information about sex, age, serological test results, HLA DQ2/DQ8 haplotypes, mucosal atrophy, gastrointestinal and extra-intesti…
Binding of basic amphipathic peptides to neutral phospholipid membranes: a thermodynamic study applied to dansyl-labeled melittin and substance P ana…
1997
A thermodynamic approach is proposed to quantitatively analyze the binding isotherms of peptides to model membranes as a function of one adjustable parameter, the actual peptide charge in solution z(p)+. The main features of this approach are a theoretical expression for the partition coefficient calculated from the molar free energies of the peptide in the aqueous and lipid phases, an equation proposed by S. Stankowski [(1991) Biophysical Journal, Vol. 60, p. 341] to evaluate the activity coefficient of the peptide in the lipid phase, and the Debye-Huckel equation that quantifies the activity coefficient of the peptide in the aqueous phase. To assess the validity of this approach we have s…