Search results for "aminopeptidases"
showing 10 items of 22 documents
Constitutive Activation of the Midgut Response to Bacillus thuringiensis in Bt-Resistant Spodoptera exigua
2010
Bacillus thuringiensis is the most effective microbial control agent for controlling numerous species from different insect orders. The main threat for the long term use of B. thuringiensis in pest control is the ability of insects to develop resistance. Thus, the identification of insect genes involved in conferring resistance is of paramount importance. A colony of Spodoptera exigua (Lepidoptera: Noctuidae) was selected for 15 years in the laboratory for resistance to Xentari (TM), a B. thuringiensis-based insecticide, reaching a final resistance level of greater than 1,000-fold. Around 600 midgut ESTs were analyzed by DNA-macroarray in order to find differences in midgut gene expression …
Brief Report: Functional Interaction of Endoplasmic Reticulum Aminopeptidase 2 and HLA-B27 Activates the Unfolded Protein Response.
2017
Objective: The basic mechanisms underlying the pathogenesis of ankylosing spondylitis (AS) remain unresolved. We previously reported an association of the single-nucleotide polymorphism (SNP) rs2549782 in the endoplasmic reticulum aminopeptidase 2 gene (ERAP2) with AS. It is known that patients homozygous for the G allele (GG) of another ERAP2 SNP, rs2248374, lack expression of ERAP2 (ERAP2 null). The present study utilized this information to study the impact of ERAP2 deficiency on HLAâB27 expression in patients with AS, specifically focusing on the functional interaction of ERAP2 and HLAâB27 in peripheral blood mononuclear cells (PBMCs) from patients with AS and assessing the effects …
Disease-associated polymorphisms in ERAP1 do not alter endoplasmic reticulum stress in patients with ankylosing spondylitis
2014
The mechanism by which human leukocyte antigen B27 (HLA-B27) contributes to ankylosing spondylitis (AS) remains unclear. Genetic studies demonstrate that association with and interaction between polymorphisms of endoplasmic reticulum aminopeptidase 1 (ERAP1) and HLA-B27 influence the risk of AS. It has been hypothesised that ERAP1-mediated HLA-B27 misfolding increases endoplasmic reticulum (ER) stress, driving an interleukin (IL) 23-dependent, pro-inflammatory immune response. We tested the hypothesis that AS-risk ERAP1 variants increase ER-stress and concomitant pro-inflammatory cytokine production in HLA-B27(+) but not HLA-B27(-) AS patients or controls. Forty-nine AS cases and 22 healthy…
Selective inhibition of binding of Bacillus thuringiensis Cry1Ab toxin to cadherin-like and aminopeptidase proteins in brush-border membranes and dis…
2007
Binding analyses with denatured epithelial membrane proteins from Bt (Bacillus thuringiensis) demonstrated at least two kinds of proteins, APNs (aminopeptidases N) and cadherin-like proteins, as possible receptors for the Cry1A class of Bt toxins. Two alternative models have been proposed, both based on initial toxin binding to a cadherin-like protein, but one involving APN and the other not. We have used two Bombyx mori strains (J65 and Kin), which are highly susceptible to Cry1Ab, to study the role of these two types of receptors on Cry1Ab toxin binding and cytotoxicity by means of the inhibitory effect of antibodies. BBMVs (brush-border membrane vesicles) of strain J65 incubated with lab…
Spectrophotometric and voltammetric determination of 2,5-dimethylaniline as potential product of enzymatic splitting of XY-2,5-dimethylanilide type s…
1999
A method for determination of 2,5-dimethylaniline is proposed. The procedure enables both spectrophotometrical and voltammetric measurements. The spectrophotometrical determination at λmax = 385.8 nm is possible for concentrations up to 1.25 × 10-6 mol l-1. The voltammetric method takes more time, however, due to the adsorptive enrichment of the substrate it is possible to determine concentrations in the range of 10-7 mol l-1). In the paper the optimal conditions and parameters for the determination are suggested.
Morphological studies on CLN2
2001
Electron microscopic, fluorescence microscopic, and immunohistochemical studies earlier performed on archivalcerebral tissue from Max Bielchowsky's original three patients revealed curvilinear bodies rich in subunit C of mitochondrial ATP synthase (SCMAS). Recent progress in the elucidation of CLN2, i.e. identification of the defective lysosomal enzyme tripeptidyl-peptidase I (TPP-I) and mutations in the CLN2 gene have further corroborated earlier data. Immunohistochemically the absence of the TPP-I protein could be confirmed in the archival tissues using pathological controls. Unlike biochemistry, immunohistochemistry enables examination of these archival tissues elucidating the causative …
Shotgun Proteomics of Isolated Urinary Extracellular Vesicles for Investigating Respiratory Impedance in Healthy Preschoolers
2021
Urine proteomic applications in children suggested their potential in discriminating between healthy subjects from those with respiratory diseases. The aim of the current study was to combine protein fractionation, by urinary extracellular vesicle isolation, and proteomics analysis in order to establish whether different patterns of respiratory impedance in healthy preschoolers can be characterized from a protein fingerprint. Twenty-one 3–5-yr-old healthy children, representative of 66 recruited subjects, were selected: 12 late preterm (LP) and 9 full-term (T) born. Children underwent measurement of respiratory impedance through Forced Oscillation Technique (FOT) and no significant differen…
Prostasome-like vesicles stimulate acrosome reaction of pig spermatozoa
2007
Abstract Background The presence of small membranous particles characterizes the male genital fluids of different mammalian species. The influence of semen vesicles, denominated prostasomes, on sperm functional properties has been well documented in humans, but their biological activity is scarcely known in other species. The present work investigated prostasome-like vesicles in pig semen for their ability to interact with spermatozoa and to affect acrosome reaction. Methods Prostasome-like vesicles have been isolated from pig seminal plasma by high-speed centrifugation and Sephadex G-200 gel chromatography. Morphology of purified vesicles has been checked by scanning electron microscopy wh…
Structure-Guided, Single-Point Modifications in the Phosphinic Dipeptide Structure Yield Highly Potent and Selective Inhibitors of Neutral Aminopepti…
2014
Seven crystal structures of alanyl aminopeptidase from Neisseria meningitides (the etiological agent of meningitis, NmAPN) complexed with organophosphorus compounds were resolved to determine the optimal inhibitor–enzyme interactions. The enantiomeric phosphonic acid analogs of Leu and hPhe, which correspond to the P1 amino acid residues of well-processed substrates, were used to assess the impact of the absolute configuration and the stereospecific hydrogen bond network formed between the aminophosphonate polar head and the active site residues on the binding affinity. For the hPhe analog, an imperfect stereochemical complementarity could be overcome by incorporating an appropriate P1 side…
Late infantile neuronal ceroid lipofuscinosis: Quantitative description of the clinical course in patients withCLN2 mutations
2002
We examined 26 individuals with clinical and electron microscopic signs of late infantile neuronal ceroid lipofuscinosis (LINCL). In 22 cases, we found both pathogenic alleles. Sixteen patients exclusively carried either one or a combination of the two common mutations R208X and IVS5-1G > C. In the remaining cases, four missense mutations could be detected, of which R127Q, N286S, and T353P represent novel, previously not described alleles. A clinical performance score was developed by rating motor, visual, and verbal functions and the incidence of cerebral seizures in 3-month intervals during the course of the disease. A Total Disability Score was derived by summing up the single scores for…