Percutaneous injection of thrombin for the treatment of pseudoaneurysms: the German multicentre registry.

Aims: False aneurysms can be treated surgically or by ultrasound guided manual compression. Another method is to inject thrombin into the aneurysm under ultrasound guidance. We evaluated safety and efficacy of this approach in a multicentre registry.

Validation of dual-chamber pacemaker diagnostic data using dual-channel stored electrograms.

Background: Pacemaker diagnostic counters are used to guide device programming and patient management. However, these data are susceptible to inappropriate classification of events. The aim of this multicenter study was to evaluate pacemaker diagnostic data using stored intracardiac electrograms (EGMs).

High-resolution crystal structures of Caldicellulosiruptor strain Rt8B.4 carbohydrate-binding module CBM27-1 and its complex with mannohexaose.

Carbohydrate-binding modules (CBMs) are the most common non-catalytic modules associated with enzymes active in plant cell-wall hydrolysis. Despite the large number of putative CBMs being identified by amino acid sequence alignments, only few representatives have been experimentally shown to have a carbohydrate-binding function. Caldicellulosiruptor strain Rt8B.

Folding and stability of the leucine-rich repeat domain of internalin B from Listeri monocytogenes.

Internalin B (InlB), a surface protein of the human pathogen Listeria monocytogenes, promotes invasion into various host cell types by inducing phagocytosis of the entire bacterium. The N-terminal half of InlB (residues 36-321, InlB321), which is sufficient for this process, contains a central leucine-rich repeat (LRR) domain that is flanked by a small alpha-helical cap and an immunoglobulin (Ig)-like domain. Here we investigated the spectroscopic properties, stability and folding of InlB321 and of a shorter variant lacking the Ig-like domain (InlB248).

[Results of single head VDD-stimulation].

VDD pacing systems provide a physiologic AV synchronous stimulation with only one lead in patients with high degree AV block and normal sinus node function. They compete with DDD systems.    This overview presents actual results of VDD stimulation concerning implantation, atrial sensing and AV synchrony, as well as stability of sinus node function.

Temperature-induced changes in copper centers and protein conformation of two fungal laccases from Coriolus hirsutus and Coriolus zonatus.

The paper reports on two fungal laccases from Coriolus hirsutus and Coriolus zonatus and their type-2 copper-depleted derivatives. Temperature-induced changes of the copper centers were characterized by optical and electron paramagnetic resonance (EPR) spectroscopy, and the overall protein stability by differential scanning microcalorimetry. The intact enzymes showed highly cooperative thermal unfolding transitions at about 90 degrees C.

Enthalpic barriers to the hydrophobic binding of oligosaccharides to phage P22 tailspike protein.

The structural thermodynamics of the recognition of complex carbohydrates by proteins are not well understood. The recognition of O-antigen polysaccharide by phage P22 tailspike protein is a highly suitable model for advancing knowledge in this field. The binding to octa- and dodecasaccharides derived from Salmonella enteritidis O-antigen was studied by isothermal titration calorimetry and stopped-flow spectrofluorimetry.

[The treatment of iatrogenic spurious aneurysm of the femoral artery by direct thrombin injection].

Background And Objective: After percutaneous catheter introduction a false aneurysm occasionally develops at the site of puncture. This has been treated either surgically or, more recently, by ultrasound-guided compression. A new method has been tried in which the false aneurysm is thrombosed by injecting thrombin into it.

[Primary stent implantation in the internal carotid artery].

Background And Objective: Advances in interventional catheter technology have made it possible to dilate stenoses also in the internal carotid artery (ICA). This may cause cerebral emboli, but primary stent implantation may fixate atherosclerotic material on the vessel wall and thus prevent embolization.

Patients And Methods: Marked stenosis in the ICA was treated by balloon dilatation in 71 consecutive patients aged between 40 and 85 years (mean 69 +/- 9 years).

Impact of the presequence of a mitochondrium-targeted precursor, preadrenodoxin, on folding, catalytic activity, and stability of the protein in vitro.

Bovine preadrenodoxin, an adrenocortical precursor protein destined for mitochondrial import, was expressed in Escherichia coli as an [2Fe-2S] cluster-containing protein. It was found in inclusion bodies, purified from there, and finally reconstituted to obtain soluble holo-protein. The impact of the presequence on folding of the protein using biochemical and biophysical approaches has been investigated.

Stability and co-operative properties of partially folded proteins.

Biophysical and thermodynamic properties of various partially folded forms of proteins are considered which can be obtained by (a) removal of prosthetic groups, (b) acid denaturation, (c) melting of subdomain-containing proteins, and (d) selective cleavage of disulfides. The examples of alpha-lactalbumin and myoglobin will be discussed in more detail. The existence of both co-operative and gradual transitions is shown.

Role of non-compatible osmolytes in the stabilization of proteins during heat stress.

This study is a systematic attempt to understand the roles of non-compatible osmolytes, i.e. solutes that have inhibitory effects on enzymes, in the stabilization of proteins against denaturing stress.

Is the molten globule a third thermodynamic state of protein? The example of alpha-lactalbumin.

Thermal and denaturant-induced transitions of the acid molten globule state of bovine alpha-lactalbumin (acid [A] state) are analyzed by scanning calorimetry, titration calorimetry, viscosimetry, and derivative spectroscopy. A denaturant-induced heat effect of the A state is shown by a calorimetric difference titration of the A-state versus unfolded (reduced) alpha-lactalbumin. However, changes of viscosity and derivative spectra do not parallel the heat effect.

Evidence that nonbilayer phase propensity of the membrane is important for the side chain cleavage activity of cytochrome P450SCC.

To analyze whether specific protein-lipid interactions or physical features of the membrane contribute to cytochrome P450SCC (CYP11A1) activation by lipids, dimyristoylphosphatidylcholine/cardiolipin and dimyristoylphosphatidylcholine/branched phosphatidylcholine vesicles of defined acyl chain structure were studied for their ability to stimulate the side chain cleavage activity of the enzyme. Activation was found to increase with the mole percent of nonbilayer lipids in the system and the chain lengths of both the branched and main fatty acyl chains of the activator lipid. Unsaturation provided by dioleoylphosphatidylcholine as host lipid leads to a further increase in the potency of the branched phosphatidylcholines to activate the enzyme.

Ferredoxin from the hyperthermophile Thermotoga maritima is stable beyond the boiling point of water.

Heat-stable proteins from hyperthermophilic microorganisms are ideally suited for investigating protein stability and evolution. We measured with differential scanning calorimetry and optical absorption spectroscopy the thermal stability of [4Fe-4S] ferredoxin from Thermotoga maritima (tfdx), which is a small electron transfer protein. The results are consistent with two-state unfolding at the record denaturation temperature of 125 degrees C.

The conformational stability of alpha-crystallin is rather low: calorimetric results.

The eye lens protein and chaperonin, alpha-crystallin, was studied by differential scanning microcalorimetry, spectroscopy and size exclusion chromatography. The thermal transition of alpha-crystallin proceeds at Ttrs = 59.8 +/- 0.

Conformational stability of adrenodoxin mutant proteins.

Adrenodoxin and the mutants at the positions T54, H56, D76, Y82, and C95, as well as the deletion mutants 4-114 and 4-108, were studied by high-sensitivity scanning microcalorimetry, limited proteolysis, and absorption spectroscopy. The mutants show thermal transition temperatures ranging from 46 to 56 degrees C, enthalpy changes from 250 to 370 kJ/mol, and heat capacity change delta Cp = 7.28 +/- 0.

Dimer structure as a minimum cooperative subunit of small heat-shock proteins.

Recently, it has been shown that small heat-shock proteins (Hsp25, Hsp27) are molecular chaperones. They bind to thermally unfolded proteins and can also assist refolding of denatured proteins. Mammalian small Hsps can form oligomeric structures of about 32 subunits.

Interaction of phosphatidylcholine liposomes with the human stratum corneum.

The interaction of dimyristoylphosphatidylcholine liposomes with the human stratum corneum was investigated by confocal laser scanning microscopy and differential scanning calorimetry. Human skin is characterized by a high autofluorescence. By introducing appropriate optical filters the autofluorescence of the skin was depressed and the penetration profile of fluorescence labelled vesicles was investigated.

Conformational stability of bovine holo and apo adrenodoxin--a scanning calorimetric study.

Holo and apo adrenodoxin were studied by differential scanning calorimetry, absorption spectroscopy, limited proteolysis, and size-exclusion chromatography. To determine the conformational stability of adrenodoxin, a method was found that prevents the irreversible destruction of the iron-sulfur center. The approach makes use of a buffer solution that contains sodium sulfide and mercaptoethanol.

Cold denaturation of yeast phosphoglycerate kinase: which domain is more stable?

Under destabilising conditions both heat and cold denaturation of yeast phosphoglycerate kinase (PGK) can be observed. According to previous interpretation of experimental data and theoretical calculations, the C-terminal domain should be more stable than the N-terminal domain at all temperatures. We report on thermal unfolding experiments with PGK and its isolated domains, which give rise to a revision of this view.

X-ray crystallographic and calorimetric studies of the effects of the mutation Trp59-->Tyr in ribonuclease T1.

Two mutants of ribonuclease T1 (RNaseT1), [59-tyrosine]ribonuclease T1 (W59Y) and [45-tryptophan,59-tyrosine]ribonuclease T1 (Y45W/W59Y) possess between 150% and 190% wild-type activity. They have been crystallised as complexes of the inhibitor 2'-guanylic acid and analysed by X-ray diffraction at resolutions of 0.23 nm and 0.

Thermodynamics of apocytochrome b5 unfolding.

Apocytochrome b5 from rabbit liver was studied by scanning calorimetry, limited proteolysis, circular dichroism, second derivative spectroscopy, and size exclusion chromatography. The protein is able to undergo a reversible two-state thermal transition. However, transition temperature, denaturational enthalpy, and heat capacity change are reduced compared with the holoprotein.

Apocytochrome P450cam is a native protein with some intermediate-like properties.

Holo- and apocytochrome P450cam were studied by differential scanning calorimetry (DSC), limited proteolysis, second-derivative spectroscopy, circular dichroism, and size-exclusion chromatography. The holoprotein shows three folding units (domains) in DSC. The prosthetic group is related to the most unstable domain, which has a thermal transition at 41.

Cold denaturation-induced conformational changes in phosphoglycerate kinase from yeast.

The temperature-dependent conformational equilibrium of 3-phosphoglycerate kinase has been studied in the temperature range from 1 to 30 degrees C by means of dynamic light scattering, small-angle X-ray scattering, differential scanning calorimetry, circular dichroism spectroscopy, and fluorescence spectroscopy. At 28 degrees C and in the presence of 0.7 M guanidine hydrochloride (GuHCl), the radius of gyration (RG) and the Stokes radius (RS) are 2.