Recurrent endocarditis on restrictive perimembranous septal defect causing aortic insufficiency.

Infective endocarditis (IE) in children is a rare entity which presents a high rate of events during follow-up. Congenital heart disease, i particular ventricular septal defect (VSD), is the main predisposing condition to IE at those ages. The long-term risk of IE is of concern and whose follow-up can be complicated by a relapse of IE and reintervention.

Prognostic Value of ISS and TRISS Scores in Tunisian Terrorism Victims.

Introduction: Injuries caused by terrorism attacks are one of the urgent problems of the society and the health system. In this work, we aimed to assess the injury severity score (ISS) and trauma injury severity score (TRISS) in Tunisian military combatants injured during terrorism attacks.

Materials And Methods: A total of 153 victims of terrorism admitted to the Military Hospital of Tunis between January 2012 and January 2017 were included.

Aortic floating thrombus in patients with COVID-19: a report of eight cases.

Background: Thromboembolic events of COVID-19 are due to hyperinflammatory process associated with hypercoagulable state. The aim of the study was to determine characteristics and clinical outcomes of patients with COVID-19 who presented with aortic thrombus.

Methods: We retrospectively conducted a single-center, descriptive study over a period of 1 year and 7 months, between June 2021 and December 2022, involving eight patients with documented SARS-CoV-2 infection associated with aortic thrombus revealed by acute limb ischemia.

Novel Stable Protease Inhibitor from Flowers with Antimicrobial and Antitumoral Activities.

A novel protease inhibitor isolated from date palm flowers (PIDF) was purified and characterized. A heat and acidic treatment step followed by ethanol precipitation and reverse-phase high-performance chromatography was applied to purify this natural protease inhibitor to homogeneity with a single band of about 19 kDa. The stability study depicted that PIDF was fully stable at 40 °C and retained 65% of its initial activity after heating at 50 °C for 24 h.

Functional Characterization and Anti-Tumor Effect of a Novel Group II Secreted Phospholipase A from Snake Venom of Saudi .

Secreted phospholipases A are snake-venom proteins with many biological activities, notably anti-tumor activity. Phospholipases from the same snake type but different geographical locations have shown similar biochemical and biological activities with minor differences in protein sequences. Thus, the discovery of a new phospholipase A with unique characteristics identified in a previously studied venom could suggest the origins of these differences.

Biodiesel Production by Single and Mixed Immobilized Lipases Using Waste Cooking Oil.

Biodiesel is one of the important biofuels as an alternative to petroleum-based diesel fuels. In the current study, enzymatic transesterification reaction was carried out for the production of biodiesel from waste cooking oil (WCO) and experimental conditions were optimized, in order to reach maximum biodiesel yield. and lipase enzymes were individually immobilized on CaCO to be used as environmentally friendly catalysts for biodiesel production.

A Novel Thermostable and Alkaline Protease Produced from Isolated from Olive Oil Mill Sols Suitable to Industrial Biotechnology.

This study was conducted to identify a new alkaline and thermophilic protease (Ba.St.Pr) produced from isolated from olive oil mill sols and to evaluate its culture conditions, including temperature, pH, carbon and nitrogen sources, and incubation time.

Cytotoxic, Antioxidant, and Metabolic Enzyme Inhibitory Activities of Extracts.

Plants of the Euphorbia genus present a wide range of therapeutic applications. This study is aimed at investigating new antidigestive enzyme agents from through inhibition of lipid and carbohydrate absorption, to evaluate their potential applications for the treatment of metabolic syndrome. Lipase, phospholipase, protease, -amylase, -glucosidase, and xanthine oxidase activities under treatment with aqueous and ethanolic extracts of were observed to evaluate the inhibitory effect of these extracts, as well as their antioxidant and cytotoxic effects.

Lipid Selectivity, Orientation, and Extent of Membrane Binding of Nonacylated RP2.

Retinitis pigmentosa 2 (RP2) is an ubiquitary protein of 350 residues. The N-terminus of RP2 contains putative sites of myristoylation and palmitoylation. The dually acylated protein is predominantly localized to the plasma membrane.

Structure and binding of the C-terminal segment of R9AP to lipid monolayers.

Phototransduction cascade takes place in disc membranes of photoreceptor cells. Following its activation by light, rhodopsin activates the G-protein transducin causing the dissociation of its GTP-bound α-subunit, which in turn activates phosphodiesterase 6 (PDE6) leading to the hyperpolarization of photoreceptor cells. PDE6 must then be inactivated to return to the dark state.

Structure of the N-terminal segment of human retinol dehydrogenase 11 and its preferential lipid binding using model membranes.

Retinol dehydrogenase 11 (RDH11) has been postulated to be anchored to membranes by means of its N-terminal segment in retinal pigment epithelial (RPE) cells where it participates to the visual cycle. The analysis of the primary sequence of RDH11 revealed that its N-terminal hydrophobic segment could be involved in the anchoring of this enzyme to membranes. However, no information is yet available on the properties of this N-terminal segment to support this role.

Interaction of the Spo20 membrane-sensor motif with phosphatidic acid and other anionic lipids, and influence of the membrane environment.

The yeast protein Spo20 contains a regulatory amphipathic motif that has been suggested to recognize phosphatidic acid, a lipid involved in signal transduction, lipid metabolism and membrane fusion. We have investigated the interaction of the Spo20 amphipathic motif with lipid membranes using a bioprobe strategy that consists in appending this motif to the end of a long coiled-coil, which can be coupled to a GFP reporter for visualization in cells. The resulting construct is amenable to in vitro and in vivo experiments and allows unbiased comparison between amphipathic helices of different chemistry.

Enzymatic activity of Lecithin:retinol acyltransferase: a thermostable and highly active enzyme with a likely mode of interfacial activation.

Lecithin:retinol acyltransferase (LRAT) plays a major role in the vertebrate visual cycle. Indeed, it is responsible for the esterification of all-trans retinol into all-trans retinyl esters, which can then be stored in microsomes or further metabolized to produce the chromophore of rhodopsin. In the present study, a detailed characterization of the enzymatic properties of truncated LRAT (tLRAT) has been achieved using in vitro assay conditions.

Comparison between the behavior of different hydrophobic peptides allowing membrane anchoring of proteins.

Membrane binding of proteins such as short chain dehydrogenase reductases or tail-anchored proteins relies on their N- and/or C-terminal hydrophobic transmembrane segment. In this review, we propose guidelines to characterize such hydrophobic peptide segments using spectroscopic and biophysical measurements. The secondary structure content of the C-terminal peptides of retinol dehydrogenase 8, RGS9-1 anchor protein, lecithin retinol acyl transferase, and of the N-terminal peptide of retinol dehydrogenase 11 has been deduced by prediction tools from their primary sequence as well as by using infrared or circular dichroism analyses.

Enzymatic properties of stingray Dasyatis pastinaca group V, IIA and IB phospholipases A(2): a comparative study.

In the present study, we have purified the group V phospholipase from the heart of cartilaginous fish stingray Dasyatis pastinaca and compared its biochemical properties with group IIA (sPLA2-IIA) and IB (sPLA2-IB) phospholipases previously purified from pancreas and intestine, respectively. Group V phospholipase (sPLA2-V) was purified to homogeneity by heat treatment, ammonium sulphate precipitation and RP-HPLC. The N-terminal sequence of the purified sPLA2-V exhibits a high degree of homology with those of mammal.

Surface behavior of α-Synuclein and its interaction with phospholipids using the Langmuir monolayer technique: a comparison between monomeric and fibrillar α-Synuclein.

Due to the involvement of α-Synuclein (α-Syn) in lipid transport and its role in the normal function and in the pathology of Parkinson disease, it is important to study first the surface properties of the protein at the air/water interface and second its behavior related to biological membranes. For this purpose, the monomolecular film technique was used as membrane model to compare the interactions with various phospholipids of monomeric and fibrillar forms of α-Syn. We have determined the equilibrium surface pressure of the two forms of α-Syn (monomeric and fibrillar form) at the air/water interface.

Antibacterial properties of intestinal phospholipase A2 from the common stingray Dasyatis pastinaca.

Stingray phospholipase A(2) group IIA (SPLA(2)-IIA) was recently isolated and purified to homogeneity from the intestine of the common stingray Dasyatis pastinaca, suggesting that this enzyme plays an important role in systemic bactericidal defense. The present study showed that SPLA(2)-IIA was highly bactericidal against Gram-positive bacteria with inhibition zones and minimal inhibitory concentration values in the range of 13-25 mm and 2-8 μg/ml, respectively, whereas Gram-negative bacteria exhibited a much higher resistance. The bactericidal efficiency of SPLA(2)-IIA was shown to be unaffected by high protein and salt concentrations, but dependent upon the presence of calcium ions, and then correlated to the hydrolytic activity of membrane phospholipids.

Purification, biochemical and kinetic properties of recombinant Staphylococcus aureus lipase.

We have compared the purification procedures as well as the biochemical and kinetic properties of wild type (wt-SAL3), untagged recombinant (rec(-His)SAL3), and tagged recombinant (rec(+His)SAL3) purified forms of Staphylococcus aureus lipase (SAL3). We used the pH-stat method (with emulsified tributyrin and olive oil as substrates) and the monomolecular film technique (with the three dicaprin isomers spread in the form of monomolecular films at the air-water interface). The data obtained showed that the recombinant expression process as well as the presence of a his-tag at the N-terminus of recombinant SAL3 affects significantly many biochemical and catalytic properties.

Heterologous expression and N-terminal His-tagging processes affect the catalytic properties of staphylococcal lipases: a monolayer study.

The interfacial and kinetic properties of wild type, untagged recombinant and tagged recombinant forms of three staphylococcal lipases (SSL, SXL and SAL3) were compared using the monomolecular film technique. A kinetic study on the dependence of the stereoselectivity of these nine lipase forms on the surface pressure was performed using the three dicaprin isomers spread in the form of monomolecular films at the air-water interface. New parameters, termed Recombinant expression Effects on Catalysis (REC), N-Tag Effects on Catalysis (TEC), and N-Tag and Recombinant expression Effects on Catalysis (TREC), were introduced.

Staphylococcal lipases stereoselectively hydrolyse the sn-2 position of monomolecular films of diglyceride analogs. Application to sn-2 hydrolysis of triolein.

Using the monomolecular film technique, a kinetic study on the stereoselectivity of nine staphylococcal lipase forms was carried out with three pairs of enantiomers from diglyceride analogs (didecanoyl-deoxyamino-O-methyl glycerol, DDG) containing a single hydrolysable decanoyl ester group and two lipase-resistant groups. Our results show that the kinetic profiles of the wild type, the recombinant untagged and the recombinant tagged forms of staphylococcal lipases are significantly different. As with most of the lipases investigated so far, these staphylococcal lipases showed higher catalytic rates with primary esters than with secondary esters.

Enzymatic synthesis of eugenol benzoate by immobilized Staphylococcus aureus lipase: optimization using response surface methodology and determination of antioxidant activity.

The ability of a non-commercial immobilized Staphylococcus aureus lipase to catalyze the esterification of eugenol with benzoic acid was checked and the antioxidant power of the ester formed was evaluated. Response surface methodology based on four variables (the reaction temperature, the amount of lipase, the benzoic acid/eugenol molar ratio and the volume of solvent) was used to optimize the experimental conditions of eugenol benzoate synthesis. The maximum conversion yield (75%) was obtained using 240 IU of immobilized lipase, a benzoic acid/eugenol molar ratio of 1.

A novel hepatopancreatic phospholipase A2 from Hexaplex trunculus with digestive and toxic activities.

A marine snail digestive phospholipase A2 (mSDPL) was purified from delipidated hepatopancreas. Unlike known digestive phospholipases A2, which are 14 kDa proteins, the purified mSDPL has a molecular mass of about 30 kDa. It has a specific activity of about 180 U/mg measured at 50 degrees C and pH 8.

Crab digestive phospholipase: a new invertebrate member.

Crab digestive phospholipase (CDPL) was purified from the hepatopancreas of Carcinus mediterraneus crabs. Homogeneous enzyme was obtained after two chromatography steps: anion exchange and size exclusion HPLC column. Homogeneous CDPL has a molecular mass of 14 kDa as determined by SDS/PAGE analysis.

Involvement of Gly 311 residue on substrate discrimination, pH and temperature dependency of recombinant Staphylococcus xylosus lipase: a study with emulsified substrate.

The importance of microbial lipases like the staphylococcal ones, results not only from their significance implication in the bacterial lipid metabolism but also their involvement in some pathogenic processes. The aminoacid sequence of the mature Staphylococcus xylosus lipase (SXL) shows 99.7% identity with the mature aminoacid sequence of Staphylococcus simulans lipase (SSL) with one substitution of Gly311 by Val.