Search results for "Trypsin"
showing 10 items of 217 documents
Propeptide glycosylation and galectin‐3 binding decrease proteolytic activation of human proMMP‐9/progelatinase B
2019
Matrix metalloproteinases (MMPs) are secreted as proenzymes, containing propeptides that interact with the catalytic zinc, thereby controlling MMP activation. The MMP‐9 propeptide is unique in the MMP family because of its post‐translational modification with an N‐linked oligosaccharide. ProMMP‐9 activation by MMP‐3 occurs stepwise by cleavage of the propeptide in an aminoterminal (pro‐AT) and carboxyterminal (pro‐CT) peptide. We chemically synthesized aglycosyl pro‐AT and pro‐CT and purified recombinant glycosylated pro‐ATS f−9. First, we report new cleavage sites in the MMP‐9 propeptide by MMP‐3 and neutrophil elastase. Additionally, we demonstrated with the use of western blot analysis a…
Oxidative Stress and Endoplasmic Reticulum Stress in Rare Respiratory Diseases
2021
Several studies have shown that some rare respiratory diseases, such as alpha-1 antitrypsin deficiency (AATD), idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF), and primary ciliary dyskinesia (PCD) present oxidative stress (OS) and endoplasmic reticulum (ER) stress. Their involvement in these pathologies and the use of antioxidants as therapeutic agents to minimize the effects of OS are discussed in this review.
Nutritional Wheat Amylase-Trypsin Inhibitors Promote Intestinal Inflammation via Activation of Myeloid Cells.
2016
Background & Aims Wheat amylase-trypsin inhibitors (ATIs) are nutritional activators of innate immunity, via activation of the toll-like receptor 4 (TLR4) on myeloid cells. We aimed to characterize the biologic activity of ATIs in various foods and their effect on intestinal inflammation. Methods We selected 38 different gluten-containing and gluten-free products, either unprocessed (such as wheat, rye, barley, quinoa, amaranth, soya, lentils, and rice) or processed (such as pizza, pasta, bread, and biscuits). ATIs were extracted and their biological activities determined in TLR4-responsive mouse and human cell lines. Effects of oral ATIs on intestinal inflammation were determined in health…
Artefactual band patterns by SDS-PAGE of the Vip3Af protein in the presence of proteases mask the extremely high stability of this protein.
2018
Abstract Vip3 proteins are secretable proteins from Bacillus thuringiensis with important characteristics for the microbiological control of agricultural pests. The exact details of their mode of action are yet to be disclosed and the crystallographic structure is still unknown. Vip3 proteins are expressed as protoxins that have to be activated by the insect gut proteases. A previous study on the peptidase processing of Vip3Aa revealed that the protoxin produced artefactual band patterns by SDS-PAGE due to the differential stability of this protein and the peptidases to SDS and heating (Bel et al., 2017 Toxins 9:131). To determine whether this phenomenon also applies to other Vip3A proteins…
Insights into the Structure of the Vip3Aa Insecticidal Protein by Protease Digestion Analysis
2017
Vip3 proteins are secretable proteins from Bacillus thuringiensis whose mode of action is still poorly understood. In this study, the activation process for Vip3 proteins was closely examined in order to better understand the Vip3Aa protein stability and to shed light on its structure. The Vip3Aa protoxin (of 89 kDa) was treated with trypsin at concentrations from 1:100 to 120:100 (trypsin:Vip3A, w:w). If the action of trypsin was not properly neutralized, the results of SDS-PAGE analysis (as well as those with Agrotis ipsilon midgut juice) equivocally indicated that the protoxin could be completely processed. However, when the proteolytic reaction was efficiently stopped, it was revealed t…
Discovery and validation of 2-styryl substituted benzoxazin-4-ones as a novel scaffold for rhomboid protease inhibitors
2017
Abstract Rhomboids are intramembrane serine proteases with diverse physiological functions in organisms ranging from archaea to humans. Crystal structure analysis has provided a detailed understanding of the catalytic mechanism, and rhomboids have been implicated in various disease contexts. Unfortunately, the design of specific rhomboid inhibitors has lagged behind, and previously described small molecule inhibitors displayed insufficient potency and/or selectivity. Using a computer-aided approach, we focused on the discovery of novel scaffolds with reduced liabilities and the possibility for broad structural variations. Docking studies with the E. coli rhomboid GlpG indicated that 2-styry…
Accelerated telomere attrition in children and teenagers with α1-antitrypsin deficiency.
2016
Numerous studies have shown that oxidative stress accelerates telomere shortening in several lung pathologies. Since oxidative stress is involved in the pathophysiology of α1-antitrypsin deficiency (AATD), we hypothesised that telomere shortening would be accelerated in AATD patients. This study aimed to assess telomere length in AATD patients and to study its association with α1-antitrypsin phenotypes.Telomere length, telomerase activity, telomerase reverse transcriptase (hTERT) expression and biomarkers of oxidative stress were measured in 62 children and teenagers (aged 2–18 years) diagnosed with AATD and 18 controls (aged 3–16 years).Our results show that intermediate-risk (MZ; SZ) and …
Reply to Comment on Huang, X., et al. “Sourdough Fermentation Degrades Wheat Alpha-Amylase/Trypsin Inhibitor (ATI) and Reduces Pro-Inflammatory Activ…
2020
We thank Dr [...]
Nitration of Wheat Amylase Trypsin Inhibitors Increases Their Innate and Adaptive Immunostimulatory Potential
2018
Amylase trypsin inhibitors (ATI) can be found in all gluten containing cereals and are, therefore, ingredient of basic foods like bread or pasta. In the gut ATI can mediate innate immunity via activation of the Toll-like receptor 4 (TLR4) on immune cells residing in the lamina propria, promoting intestinal, as well as extra-intestinal, inflammation. Inflammatory conditions can induce formation of peroxynitrite (ONOO-) and, thereby, endogenous protein nitration in the body. Moreover, air pollutants like ozone (O3) and nitrogen dioxide (NO2) can cause exogenous protein nitration in the environment. Both reaction pathways may lead to the nitration of ATI. To investigate if and how nitration mo…
The Overlapping Area of Non-Celiac Gluten Sensitivity (NCGS) and Wheat-Sensitive Irritable Bowel Syndrome (IBS): An Update
2017
Gluten-related disorders have recently been reclassified with an emerging scientific literature supporting the concept of non-celiac gluten sensitivity (NCGS). New research has specifically addressed prevalence, immune mechanisms, the recognition of non-immunoglobulin E (non-IgE) wheat allergy and overlap of NCGS with irritable bowel syndrome (IBS)-type symptoms. This review article will provide clinicians with an update that directly impacts on the management of a subgroup of their IBS patients whose symptoms are triggered by wheat ingestion.