Search results for "Amidase"

Irreversible gelation of thermally unfolded proteins:structural and mechanical properties of lysozyme aggregates

2010

The formation of protein aggregates is important in many fields of life science and technology. The morphological and mechanical properties of protein solutions depend upon the molecular conformation and thermodynamic and environmental conditions. Non-native or unfolded proteins may be kinetically trapped into irreversible aggregates and undergo precipitation or gelation. Here, we study the thermal aggregation of lysozyme in neutral solutions. We characterise the irreversible unfolding of lysozyme by differential scanning calorimetry. The structural properties of aggregates and their mechanisms of formation with the eventual gelation are studied at high temperature by spectroscopic, rheolog…

Calculation of partition coefficient and hydrophobic moment of the secondary structure of lysozyme

2001

A method that permits a semiquantitative estimate of the partitioning of any solute between any two media is presented. As an example, the partition coefficients and hydrophobic moment of the secondary structure of lysozyme are calculated. Program GSCAP is written as a version of Pascal's solvent-dependent conformational analysis (SCAP) program. The dipole moments calculated for the helices are trebled with respect to that for the sheet. For helices, the main contribution to the water-accessible surface area is the hydrophobic term, while the hydrophilic part dominates in the sheet. Molecular globularity and the three studied partition coefficients differentiate between helices and sheet.

Influence of anti-inflammatory flavonoids on degranulation and arachidonic acid release in rat neutrophils.

1994

We assessed the effects of 24 flavonoid derivatives, reported as anti-inflammatory, on lysosomal enzyme secretion and arachidonic acid release in rat neutrophils. Amentoflavone, quercetagetin- 7-O -glucoside, apigenin, fisetin, kaem pferol, luteolin and quercetin were the most potent inhibitors of β-glucuronidase and lysozyme release. The first com pound was also able to inhibit basal release. These flavonoids besides chrysin and to a reduced extent, naringenin, significantly inhibited arachidonic acid release from membranes. A correlation between degranulation and arachidonic acid release was found for this series of compounds. Structureactivity relationships and implications for the anti-…

Combination of acoustic levitation with small angle scattering techniques and synchrotron radiation circular dichroism. Application to the study of p…

2016

Abstract Background The acoustic levitation technique is a useful sample handling method for small solid and liquids samples, suspended in air by means of an ultrasonic field. This method was previously used at synchrotron sources for studying pharmaceutical liquids and protein solutions using x-ray diffraction and small angle x-ray scattering (SAXS). Methods In this work we combined for the first time this containerless method with small angle neutron scattering (SANS) and synchrotron radiation circular dichroism (SRCD) to study the structural behavior of proteins in solutions during the water evaporation. SANS results are also compared with SAXS experiments. Results The aggregation behavi…

Strong stabilization of amorphous calcium carbonate emulsion by ovalbumin: gaining insight into the mechanism of 'polymer-induced liquid precursor' p…

2011

8 pages; International audience; The impact of the ovo proteins ovalbumin and lysozyme-present in the first stage of egg shell formation-on the homogeneous formation of the liquid amorphous calcium carbonate (LACC) precursor, was studied by a combination of complementing methods: in situ WAXS, SANS, XANES, TEM, and immunogold labeling. Lysozyme (pI = 9.3) destabilizes the LACC emulsion whereas the glycoprotein ovalbumin (pI = 4.7) extends the lifespan of the emulsified state remarkably. In the light of the presented data: (a) Ovalbumin is shown to behave commensurable to the 'polymer-induced liquid precursor' (PILP) process proposed by Gower et al. Ovalbumin can be assumed to take a key rol…

Late-Onset Globoid Cell Leukodystrophy: Unusual Ultrastructural Pathology and Subtotal β-Galactocerebrosidase Deficiency

1990

An 11-year-old girl was found to have severely reduced β-galactocerebrosidase activity as evidence of late-onset globoid cell leukodystrophy, while her mother had almost normal enzyme activity in circulating white blood cells. Clinically, the patient showed a remitting course marked by seizures, ataxia, white-matter disease on computed tomographic scan, and reduced conduction velocities of peripheral nerves. Symptoms improved somewhat around the age of 10 years. Two sural nerve biopsies, performed 6 years apart, disclosed a demyelinating neuropathy. By electron microscopy, membrane-bound vacuolar lysosomes in Schwann cells of myelinated axons, unlike the typical needlelike inclusions seen …

Early access experience with VPRIV®: Recommendations for ‘core data’ collection

2011

Acid ceramidase deficiency: Farber lipogranulomatosis, spinal muscular atrophy associated with progressive myoclonic epilepsy and peripheral osteolys…

2020

Abstract An inherited deficiency of the lysosomal enzyme ceramidase leads to accumulation of the sphingolipid ceramide in several organs such as skin, liver, brain and other tissues, resulting in a broad spectrum of clinical manifestations. The most common form, called Farber lipogranulomatosis, is characterized by subcutaneous skin nodules and a progressive hoarseness, in many cases also the central nervous system is affected. A lethal hydrops fetalis represents the most severe form. A ceramidase deficiency was also found in a few patients in whom neurological symptoms such as spinal muscular atrophy and myoclonus epilepsy dominated the clinical picture, in other adult patients peripheral …

Differentiation of Penicillium griseofulvum Dierckx isolates by enzyme assays and by patulin and griseofulvin analyses

1990

The production of patulin and griseofulvin by 49 different isolates of Penicillium griseofulvum Dierckx was analyzed by high-performance liquid chromatography. Eleven isolates were obtained from pistachio nuts, 37 were obtained from wheat seeds, and 1 was obtained from the American Type Culture Collection. Activities of 19 enzymes were also assayed by the API ZYM system. From these results it may be deduced that there are two different groups among the strains tested which cannot be distinguished by morphological and cultural characteristics. One group of isolates did not produce detectable amounts of patulin and griseofulvin when grown in sucrose-yeast extract and Wickerham media, while en…

Über die Hemmung der Arginase durch Stickstofflost

1952

Liver arginase is completely inhibited by nitrogen mustard [tris-(β-chloroethyl)amine, HCl] at a final concentration of 4.6×10−4 M. This holds true for isolated liver cell nuclei also. The experimental conditions are described exactly.