Search results for "Peptide"
showing 10 items of 4589 documents
The protease complex consisting of dipeptidyl peptidase IV and seprase plays a role in the migration and invasion of human endothelial cells in colla…
2006
Abstract Dipeptidyl peptidase IV (DPP4/CD26) and seprase/fibroblast activation protein α are homologous type II transmembrane, homodimeric glycoproteins that exhibit unique prolyl peptidase activities. Human DPP4 is ubiquitously expressed in epithelial and endothelial cells and serves multiple functions in cleaving the penultimate positioned prolyl bonds at the NH2 terminus of a variety of physiologically important peptides in the circulation. Recent studies showed a linkage between DPP4 and down-regulation of certain chemokines and mitogenic growth factors, and degradation of denatured collagens (gelatin), suggesting a role of DPP4 in the cell invasive phenotype. Here, we found the existen…
Probes for studying cholesterol binding and cell biology.
2011
Cholesterol is a multifunctional lipid in eukaryotic cells. It regulates the physical state of the phospholipid bilayer, is crucially involved in the formation of membrane microdomains, affects the activity of many membrane proteins, and is the precursor for steroid hormones and bile acids. Thus, cholesterol plays a profound role in the physiology and pathophysiology of eukaryotic cells. The cholesterol molecule has achieved evolutionary perfection to fulfill its different functions in membrane organization. Here, we review basic approaches to explore the interaction of cholesterol with proteins, with a particular focus on the high diversity of fluorescent and photoreactive cholesterol prob…
ADAM10 in Alzheimer's disease: Pharmacological modulation by natural compounds and its role as a peripheral marker.
2019
Abstract Alzheimer’s disease (AD) represents a global burden in the economics of healthcare systems. Amyloid-β (Aβ) peptides are formed by amyloid-β precursor protein (AβPP) cleavage, which can be processed by two pathways. The cleavage by the α-secretase A Disintegrin And Metalloprotease 10 (ADAM10) releases the soluble portion (sAβPPα) and prevents senile plaques. This pathway remains largely unknown and ignored, mainly regarding pharmacological approaches that may act via different signaling cascades and thus stimulate non-amyloidogenic cleavage through ADAM10. This review emphasizes the effects of natural compounds on ADAM10 modulation, which eventuates in a neuroprotective mechanism. M…
Protein expression in submandibular glands of young rats is modified by a high-fat/high-sugar maternal diet
2018
International audience; OBJECTIVE: Maternal diet has consequences on many organs of the offspring, but salivary glands have received little attention despite the importance of the saliva secretory function in oral health and control of food intake. The objective of this work was therefore to document in rats the impact of maternal high-fat/high-sugar diet (Western Diet) on submandibular glands of the progeny. DESIGN: Sprague-Dawley rat dams were fed either a Western diet or control diet during gestation and lactation and their pups were sacrificed 25 days after birth. The pups' submandibular gland protein content was characterized by means of 2D-electrophoresis followed by LC-MS/MS. Data we…
Less but better: cardioprotective lipid profile of patients with GCK-MODY despite lower HDL cholesterol level
2014
Patients with diabetes caused by single-gene mutations generally exhibit an altered course of diabetes. Those with mutations of the glucokinase gene (GCK-MODY) show good metabolic control and low risk of cardiovascular complications despite paradoxically lowered high-density lipoprotein (HDL) cholesterol levels. In order to investigate the matter, we analyzed the composition of low-density lipoprotein (LDL) and HDL subpopulations in such individuals. The LipoPrint(©) system (Quantimetrix, USA) based on non-denaturing, linear polyacrylamide gel electrophoresis was used to separate and measure LDL and HDL subclasses in fresh-frozen serum samples from patients with mutations of glucokinase or …
Antimicrobial peptides from echinoderms as antibiofilm agents: a natural strategy to combat bacterial infections
2014
AbstractIncreased attention has been focused on marine invertebrates as a source of bioactive molecules for biomedical applications. Many bioactive molecules are part of the innate immune system. Some more recently isolated compounds, mainly from the sea urchin and the sea cucumber, are antimicrobial peptides (AMPs) active against Gram-positive and Gram-negative bacteria, and fungi. In this review we described the most recent studies on AMPs isolated from echinoderms. AMPs are small peptides (< 10 kDa) with cationic charge and amphipathic structure. Recently, it was demonstrated that in the coelomocyte lysates of Paracentrotus lividus and Holothuria tubulosa, AMPs possess activity against s…
Why Women Have More Alzheimer's Disease Than Men: Gender and Mitochondrial Toxicity of Amyloid-β Peptide
2010
The main risk factors for developing Alzheimer's disease (AD) are age and gender. The incidence of the disease is higher in women than in men, and this cannot simply be attributed to the higher longevity of women versus men. Thus, there must be a specific pathogenic mechanism to explain the higher incidence of AD cases in women. In this regard, it is notable that mitochondria from young females are protected against amyloid-beta toxicity, generate less reactive oxygen species, and release less apoptogenic signals than those from males. However, all this advantage is lost in mitochondria from old females. Since estrogenic compounds protect against mitochondrial toxicity of amyloid-beta, estr…
N-valproyl-L-tryptophan for CNS-targeting: synthesis, characterization and efficacy in vitro studies of a new potential antiepileptic drug.
2010
A new aminoacidic derivative of valproic acid (VPA) has been synthesized and characterized by analytical and spectral data. The rationale for the preparation of such potential antiepileptic agent is based on the observation that chemical combination of the anticonvulsant pharmacophore, VPA with essential aminoacids could afford more effective and less toxic actives. The synthesis, characterization, physico-chemical parameters functional for crossing Blood Brain Barrier of N-valproyl-L-tryptophan (4) are reported. The Log D pH7.4 (0.3) indicates that (4) is adequate to cross biological membranes. Its chemical and enzymatic stability were assessed. The experiments indicate high stability of c…
Electrostatic Tuning of the Ligand Binding Mechanism by Glu27 in Nitrophorin 7
2018
AbstractNitrophorins (NP) 1–7 are NO-carrying heme proteins found in the saliva of the blood-sucking insect Rhodnius prolixus. The isoform NP7 displays peculiar properties, such as an abnormally high isoelectric point, the ability to bind negatively charged membranes, and a strong pH sensitivity of NO affinity. A unique trait of NP7 is the presence of Glu in position 27, which is occupied by Val in other NPs. Glu27 appears to be important for tuning the heme properties, but its influence on the pH-dependent NO release mechanism, which is assisted by a conformational change in the AB loop, remains unexplored. Here, in order to gain insight into the functional role of Glu27, we examine the ef…
Human kininogens interact with M protein, a bacterial surface protein and virulence determinant.
1995
Streptococcus pyogenes, the most significant streptococcal species in clinical medicine, expresses surface proteins with affinity for several human plasma proteins. Here we report that kininogens, the precursors to the vasoactive kinins, bind to the surface of S. pyogenes. M protein, a surface molecule and a major virulence factor-in these bacteria, occurs in &gt; 80 different serotypes. Among 49 strains of S. pyogenes, all of different M serotypes, 41 bound radiolabelled kininogens, whereas 6 M protein-negative mutant strains showed no affinity. M protein of most serotypes bind fibrinogen, and among the 55 strains tested, binding of kininogens was closely correlated to fibrinogen bindi…