Search results for "Chymotrypsin"
showing 10 items of 47 documents
Colorado potato beetle chymotrypsin genes are differentially regulated in larval midgut in response to the plant defense inducer hexanoic acid or the…
2019
When Colorado potato beetle larvae ingested potato plants treated with the plant defense inducer compound hexanoic acid, midgut chymotrypsin enzyme activity increased, and the corresponding chymotrypsin genes were differentially expressed, evidence of the larval digestive proteolytic system's plasticity. We previously reported increased susceptibility to Cry3Aa toxin in larvae fed hexanoic acid treated plants. Here we show that the most expressed chymotrypsin gene in larvae fed hexanoic acid treated plants, CTR6, was dramatically downregulated in Cry3Aa intoxicated larvae. lde-miR-965-5p and lde-miR-9a-5p microRNAs, predicted to target CTR6, might be involved in regulating the response to h…
Identification of noncovalent proteasome inhibitors with high selectivity for chymotrypsin-like activity by a multistep structure-based virtual scree…
2016
Noncovalent proteasome inhibitors introduce an alternative mechanism of inhibition to that of covalent inhibitors, e.g. carfilzomib, used in cancer therapy. A multistep hierarchical structure-based virtual screening (SBVS) of the 65,375 NCI lead-like compound library led to the identification of two compounds (9 and 28) which noncovalently inhibited the chymotrypsin-like (ChT-L) activity (Ki = 2.18 and 2.12 μM, respectively) with little or no effects on the other two major proteasome proteolytic activities, trypsin-like (T-L) and post-glutamyl peptide hydrolase (PGPH) activities. A subsequent hierarchical similarity search over the full NCI database with the most active tripeptide-based inh…
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…
Serum and fecal pancreatic enzymes in beta-thalassemia major
1997
This study, using indirect tests, demonstrated that exocrine pancreatic function is impaired in a proportion of patients with beta-thalassemia major (TM), though this impairment is generally mild or moderate.Impaired structure and function of the exocrine pancreas has been reported in patients with Beta-thalassemia major.In this study we measured fecal fats and serum and fecal pancreatic enzymes in 30 patients (13 M, 17 F) with TM, mean age 22.1 yr (range 14-39) and compared them with those of a matched group of healthy controls. Results were correlated with age, serum ferritin, blood transfusion, and various nutritional parameters. Enzymes assays included: serum pancreatic amylase (PA), li…
MR imaging of pancreatic changes in patients with transfusion-dependent beta-thalassemia major.
1999
The aim of this study was to evaluate MR imaging changes of the pancreas in patients with transfusion-dependent beta-thalassemia major.Twenty patients with transfusion-dependent beta-thalassemia major were examined using MR imaging at 0.5 T, with spin-echo T1-weighted, fast spin-echo T2-weighted, and gradient-echo T2*-weighted sequences. Image analysis was performed to assess pancreas-to-fat signal intensity ratios for all pulse sequences. Pancreatic exocrine and endocrine function and serum ferritin levels were assessed. Twenty healthy volunteers underwent MR imaging with the same three sequences and served as a control group.The pancreas-to-fat signal intensity ratio was significantly dec…
Diagnostic accuracy of fecal elastase 1 assay in patients with pancreatic maldigestion or intestinal malabsorption: a collaborative study of the Ital…
2001
Several reports have indicated that fecal elastase-1 (EL-1) determination is a new, sensitive, and specific noninvasive pancreatic function test; however, very few patients with malabsorption due to small intestine diseases have been included in the previous studies. The aim of the study was to compare the diagnostic accuracy of fecal EL-1 and fecal chymotrypsin (FCT) in distinguishing between pancreatic maldigestion and intestinal malabsorption. Three groups of subjects were studied: group A included 49 patients with known cystic fibrosis (25 males, median age 5 years); group B included 43 subjects with various small intestine diseases (17 males, median age 6 years); and group C included 4…
A multicenter clinical trial on the use of alpha1-antichymotrypsin-prostate-specific antigen in prostate cancer diagnosis
2001
BACKGROUND The aim was to evaluate the clinical performance of alpha1-antichymotrypsin prostate-specific antigen (PSA-ACT) for early diagnosis of prostate cancer (PCa) in a multicenter trial. METHODS Three hundred sixty-seven white men with PCa and 290 with benign prostatic hyperplasia (BPH) with tPSA concentrations between 2 and 20 μg/L were analyzed. The Elecsys system 2010 (Roche Diagnostics, Germany) was used for determination of total PSA (tPSA) and free PSA (fPSA). The PSA-ACT test was a prototype assay used on the ES system (Roche Diagnostics). RESULTS The median concentrations of tPSA (PCa: 8.43 μg/L vs. BPH: 6.60 μg/L) and PSA-ACT (8.30 μg/L vs. 6.46 μg/L) were significantly differ…
Shared Binding Sites for the Bacillus thuringiensis Proteins Cry3Bb, Cry3Ca, and Cry7Aa in the African Sweet Potato Pest Cylas puncticollis (Brentida…
2014
ABSTRACT Bacillus thuringiensis Cry3Bb, Cry3Ca, and Cry7Aa have been reported to be toxic against larvae of the genus Cylas , which are important pests of sweet potato worldwide and particularly in sub-Saharan Africa. However, relatively little is known about the processing and binding interactions of these coleopteran-specific Cry proteins. The aim of the present study was to determine whether Cry3Bb, Cry3Ca, and Cry7Aa proteins have shared binding sites in Cylas puncticollis to orient the pest resistance strategy by genetic transformation. Interestingly, processing of the 129-kDa Cry7Aa protoxin using commercial trypsin or chymotrypsin rendered two fragments of about 70 kDa and 65 kDa. N-…
Evaluation of the proteolysis degree with the o-phthalaldehyde/N-acetyl-L-cysteine reagent
1990
The o-phthalaldehyde/N-acetyl-L-cysteine (OPA-NAC) reagent is applied to the spectrophotometric evaluation of the proteolytic activity of enzymes. The high stability of the OPA-NAC isoindoles makes a strict control of the time of reaction unnecessary. A mathematical expression is proposed to calculate proteolysis degrees, where the absorbance decrease of the OPA-NAC derivative of the protein itself during the hydrolysis process is taken into account. The method is applied to bovine serum albumine, caseine, lysozyme, lactoglobuline and protamine sulphate as substrates, and pronase, papaine, trypsin and chymotrypsin as enzymes.
Phenoloxidase characterization in vacuolar hemocytes from the solitary ascidian Styela plicata
1995
Phenoloxidase (PO) activity was shown in lysates of Styela plicata hemocytes assayed spectrophotometrically by means of L-Dopa oxidation without divalent cations. Trypsin and chymotrypsin pretreatment and preincubation with microbial lipopolysaccharides significantly activated PO, whereas laminarin or zymosan were ineffective. Soybean trypsin inhibitor, tropolone, and phenylthiourea, but not benzamidine, were inhibitors. Finally, hemocytes were separated by a discontinuous Percoll density gradient to determine which cells were active. PO activity was demonstrated, by both biochemical and cytochemical assays, in the separated fraction enriched mainly with the globular granulocytes called mor…