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Biomedical subjects

I Pilz

Publications and source records attributed to I Pilz.

At least 19 recordsLinked to original sources
PubMed2001

Incidence of pediatric rheumatic diseases in a regional population in Austria.

OBJECTIVE: To establish a population based disease registry for pediatric rheumatology in a defined population of Austria; to describe the demographic and diagnostic classification of children referred to pediatric rheumatology clinics; and to estimate the incidence of pediatric rheumatic diseases in Eastern Austria. METHODS: For 2 years (1997-98) all pediatric rheumatology centers in the area contributed data on all new cases to a prospective multicenter patient registry. Diagnostic criteria defined the rheumatic disease cases, determined by a pediatric rheumatologist, and record linkage was carried out to avoid duplication of subjects. RESULTS: Rheumatic conditions were diagnosed in 107 subjects. Juvenile rheumatoid arthritis (JRA) was the most frequently encountered rheumatic condition (49.5%), followed by spondyloarthropathy (SpA, 33.6%) and systemic lupus erythematosus (SLE, 5.6%). The mean annual incidence of JRA, SpA, and SLE among children referred to pediatric rheumatology centers was 4.28, 2.9, and 0.48 per 100,000 children at risk, respectively. CONCLUSION: Establishment of a population based disease registry led to collection of descriptive epidemiologic data on a defined regional cohort of children with rare disorders. Our registry will provide data on pediatric rheumatic diseases in a European population and will allow more accurate comparisons between populations for future research. Our data also indicate that more resources should be designated for the care of pediatric rheumatic diseases in view of the relatively high incidences of these diseases.

Adolescent↗
PubMed1996

Small-angle X-ray scattering reveals differences between the quaternary structures of oxygenated and deoxygenated tarantula hemocyanin.

Small-angle X-ray scattering (SAXS) curves have been recorded for the oxygenated and deoxygenated states of the 4 x 6-meric hemocyanin from the tarantula Eurypelma californicum. A comparison of the curves shows that the quaternary structures of the two states are different by three criteria, which all indicate that the hemocyanin is less compact in the oxygenated compared to the deoxygenated form: (a) The radius of gyration is 8.65 +/- 0.05 nm for the deoxy- and 8.80 +/- 0.05 nm for the oxy-form. (b) The maximum particle dimension amounts to 25.0 +/- 0.5 nm for the deoxy- and to 27.0 +/- 0.5 nm for the oxy-form. (c) A dip in the intramolecular distance distribution function p(r) is more pronounced and shifted to larger distances in the oxy-form. The p(r) functions based on SAXS measurements were compared to p(r) functions deduced from published electron microscopical images of three different 4 x 6-meric hemocyanins from closely related species. The p(r) functions of SAXS and electron microscopy were similar in one case, whereas in the other two cases the distance between the two 12-meric half-molecules had to be changed by 1-1.5 nm to obtain good agreement. The differences between the p(r) functions of oxygenated and deoxygenated 4 x 6-meric tarantula hemocyanin are much larger than one would expect from a comparison of X-ray structures of the oxygenated and deoxygenated states of a closely related 6-meric hemocyanin. Thus, the conformational changes upon oxygenation occur at various levels of the quaternary structure, as postulated by hierarchical theories of allosteric interactions.

Animals↗
PubMed1991

Deletion of the linker connecting the catalytic and cellulose-binding domains of endoglucanase A (CenA) of Cellulomonas fimi alters its conformation and catalytic activity.

The Pro-Thr box is a linker of 23 amino acids ((PT)4T(PT)7) connecting the catalytic domain and the cellulose-binding domain (CBD) of endoglucanase A (CenA) from the bacterium Cellulomonas fimi. Deletion of the Pro-Thr box alters the conformation of CenA by changing the relative orientation of the catalytic domain and the CBD. The tertiary structures of the catalytic domain and the CBD appear to be unchanged. The change in conformation reduces the catalytic efficiency of the enzyme and masks one of two protease-sensitive sites between the domains. The deletion does not affect the adsorption of the enzyme to microcrystalline cellulose, but it does affect its desorption from cellulose. The results suggest that the Pro-Thr box in CenA has an extended, kinked, and rigid conformation.

Actinomycetales↗
PubMed1991

Small-angle X-ray study on the quaternary structure of erythrocruorin from Caenestheria inopinata.

The erythrocruorin of the clam shrimp Caenestheria inopinata was studied in sodium phosphate buffer at pH 6.8 by small-angle X-ray scattering. The following molecular parameters were determined: radius of gyration 4.77 +/- 0.05 nm, maximum dimension 14.0 +/- 0.5 nm and a volume of 640 +/- 40 nm3. A model which fits the experimental data well is presented. The model is composed of 10 subunits arranged symmetrically in two layers, whereby five subunits are always forming a ring.

Animals↗
PubMed1990

The tertiary structure of a bacterial cellulase determined by small-angle X-ray-scattering analysis.

CenA from Cellulomonas fimi is a beta-1,4-endoglucanase that binds tightly to cellulose. X-ray-scattering analyses show that the enzyme is tadpole-shaped: the previously identified catalytic and cellulose-binding domains comprise the head and tail respectively. It appears that this structural and functional organization is common to several cellulases from bacteria and fungi.

Actinomycetales↗
PubMed1990

Quaternary structure of the giant extracellular hemoglobin of the leech Macrobdella decora.

The molecular dimensions of the extracellular hemoglobin of the leech Macrobdella decora, determined by scanning transmission electron microscopy were 29.8 nm x 19.5 nm (diameter x height) for negatively stained specimens. Measurements of molecular mass (Mm) of unstained specimens with the microscope gave Mm = 3560 +/- 160 kDa. Small-angle X-ray scattering measurements gave a diameter of 28.0(+/- 0.5) nm, radius of gyration 10.5(+/- 0.2) nm and volume 7500(+/- 300) nm3. The hemoglobin had no carbohydrate and its iron content was found to be 0.23(+/- 0.02)% (w/w), corresponding to a minimum Mm of 24,000(+/- 1300) kDa. SDS/polyacrylamide gel electrophoresis of the unreduced hemoglobin showed that it consisted of three subunits, which have apparent Mm values of 12 (1), 25 (2) and 29 kDa (3). The reduced hemoglobin consisted of four subunits, I (12 kDa), II (14 kDa), III (26 kDa) and IV (30 kDa). Subunit 1 corresponded to subunit I, subunit 2 to subunits III and IV and subunit 3 to subunit II. Partial N-terminal sequences were obtained for subunit 1, the two chains of subunit 2 and one of the two chains of subunit 3, suggesting that the hemoglobin consists of at least five different polypeptide chains. The percentage fraction of the three unreduced subunits was determined by densitometry of SDS/polyacrylamide gel patterns and quantitative determination of Coomassie R-250 dye bound to the individual bands in reduced and unreduced patterns to be, monomer (subunit I) : non-reducible subunit (subunit 2) : reducible dimer (subunit 3) = 0.35 : 0.29 : 0.35 (S.D. = +/- 0.05). This corresponded to a stoichiometry of 74 +/- 11 : 37 +/- 5 : 38 +/- 6, assuming the molecular masses to be 17 kDa, 30 kDa and 34 kDa, taking into account the anomalously high mobility of annelid globins in SDS-containing gels. The stoichiometry calculated from the amino acid compositions of the hemoglobin and the three subunits was 82 +/- 12 : 29 +/- 4 : 40 +/- 8. Gel filtration of the hemoglobin at pH 9.8, at neutral pH subsequent to dissociation at pH 4 and at neutral pH in the presence of urea and Gu.HCl provided no evidence for the existence of a putative 1/12 of the whole molecule (Mm approx. 300 kDa). Furthermore, the largest subunits obtained had Mm of 60 to 100 kDa and had a much decreased content of subunit 2, suggesting that the hemoglobin was not a simple multimeric protein. Three-dimensional reconstruction from microscope images provided a model of Macrobdella hemoglobin that is very similar to the reconstruction of Lumbricus hemoglobin: the radial mass distribution curves are virtually superimposable.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1989

Structural changes in cellobiohydrolase I upon binding of a macromolecular ligand as evident by SAXS investigations.

Xylan from Rhodymenia palmata binds to the cellobiohydrolase I from Trichoderma reesei (CBH I) or its core protein, inhibiting their activity. Adsorption onto microcrystalline cellulose (Avicel) is reduced approximately 30% for intact CBH I and nearly 50% for the core, whereas the effects with cellobiose are negligible. Structural changes concomitant with this binding are studied in solution by small angle X-ray scattering. In the "tadpole" structure typical for the CBH I [Abuja et al., 1988] the lengthening of the tail part is the most salient observation when xylan is present which accounts for an increase in Dmax (18.0 to 22.0 nm) and radius of gyration (4.74 to 5.18 nm). When xylan binds to the core the radius of gyration remains nearly unchanged. Here a model can be constructed showing a xylan molecule on the surface of the core protein near the tail part.

Adsorption↗
PubMed1988

Domain structure of cellobiohydrolase II as studied by small angle X-ray scattering: close resemblance to cellobiohydrolase I.

Evidence for a domain structure of cellobiohydrolase II (CBH II, 58 kDa) from Trichoderma reesei (Teeri et al., 1987; Tomme et al., 1988) is corroborated by results from SAXS experiments. They indicate a 'tadpole' structure for the intact CBH II in solution (Dmax = 21.5 +/- 0.5 nm; Rg = 5.4 +/- 0.1 nm) and a more isotropic, ellipsoid shape for the core protein (Dmax = 6.0 +/- 0.3 nm; Rg = 2.1 +/- 0.1 nm). The latter was obtained by partial proteolysis with papain which cleaves the native CBH II to give two fragments (Tomme et al., 1988): the core (45 kDa) with the active (hydrolytic) domain and a smaller fragment (11 kDa) coinciding with the tail part of the model and containing the binding domain for unsoluble cellulose. This peptide fragment is conserved in most cellulolytic enzymes from Trichoderma reesei (Teeri et al., 1987). It contains a conserved region (block A) and glycosylated parts (blocks B and B' duplicated and located N-terminally in CBH II). In spite of different domain arrangements in CBH I (blocks B-A at C-terminals) SAXS measurements (Abuja et al., 1988) indicate similar tertiary structures for both cellobiohydrolases although discrete differences in the tail parts exist.

Binding Sites↗
PubMed1988

Small angle X-ray scattering study on bovine porphobilinogen synthase (5-aminolaevulinate dehydratase).

The quaternary structure of the native (zinc) porphobilinogen synthase (5-amino-laevulinate dehydratase) from bovine liver and its lead-substituted derivative is studied in solution by small angle X-ray scattering. In spite of the profound inhibitory effect of lead ions in the enzyme they do not produce a change in the quaternary structure detectable by small angle X-ray scattering. The most important molecular parameters of the native enzyme were found to be: radius of gyration Rg = 4.04 +/- 0.04 nm and maximum dimension Dmax = 12.0 +/- 0.5 nm. The corresponding values for the lead derivative are: Rg = 4.26 +/- 0.1 nm and Dmax = 12.5 +/- 0.5 nm. The quaternary structure of the enzyme in solution is described by a model, which fits the experimental scattering and distance distribution function.

Animals↗
PubMed1987

Epitope localization in antigen-monoclonal-antibody complexes by small-angle X-ray scattering. An approach to domain organization in the beta 2 subunit of Escherichia coli tryptophan synthase.

Each polypeptide chain of the beta 2 subunit of Escherichia coli tryptophan synthase (EC 4.2.1.20) is made of two domains, F1 (N-terminal) and F2 (C-terminal). To determine the relative position of these domains in the native protein, complexes between beta 2 and Fab fragments from two monoclonal antibodies, one specific for F1 (68-1) and the other for F2 (93-6), have been prepared and purified. Small-angle X-ray scattering measurements have been made on solutions of each complex. From the experimental scattering curves obtained, computer modeling leads to structural models of the two beta 2-Fab complexes. Though relatively low, the resolution of these models allows the localization on beta 2 of the antigenic sites recognized by the two antibodies, to show that the C-terminal F2 domains lie at the distal ends of the elongated beta 2 protein, and to show how steric hindrance prevents beta 2, though structurally and functionally dimeric, from binding more than one Fab 93-6 fragment per dimer.

Antigen-Antibody Complex↗
PubMed1986

[Hyalinosis cutis et mucosae--Urbach-Whiete syndrome. Review and case report].

We present the Urbach-Whiete-Syndrome as a rare cause of hoarseness in children. As such patients often present initially to the E.N.T. surgeon, we should like to draw attention to this autosomal recessive condition. Only symptomatic treatment is possible, and genetic counselling should be considered. The diagnosis of the disease should be as prompt as possible.

Abnormalities, Multiple↗
PubMed1984

Small angle x-ray study on the structure of active and inactive ribulose bisphosphate carboxylase from Alcaligenes eutrophus. Evidence for a configurational change.

Two small angle x-ray scattering curves have been obtained from active and inactive ribulose 1,5-bisphosphate carboxylase from Alcaligenes eutrophus. The radius of gyration was calculated to be R = 47.8 +/- 0.1 nm for the active enzyme and R = 49.2 +/- 0.1 nm for the inactive enzyme. The maximum particle dimension amounts to 13.5 +/- 0.5 nm for the active and 15.7 +/- 0.5 nm for the inactive enzyme. A model of the active carboxylase is presented. It is in good agreement with models derived from electron microscopical data. Model calculations for the inactive enzyme show some evidence for a configurational change.

Alcaligenes↗
PubMed1984

Small-angle X-ray study of the 50 S ribosomal subunit of Escherichia coli. A comparison of different models.

A small angle X-ray scattering curve obtained from Escherichia coli 50 S subunits has been compared with the scattering curves calculated for three-dimensional 50 S models proposed by various authors. The one proposed by Lake, Stöffler and Vasiliev showed to some extent a good agreement with our experimental data. Calculating a large number of possible particle structures we found a model which optimally fits our experimental curves, but it's two-dimensional projections differ a little from the projections of 50 S subunits observed by electron microscopy.

Escherichia coli↗
PubMed1982

Small-angle X-ray scattering studies of tryptophan synthase from Escherichia coli and its alpha and beta 2 subunits.

The alpha and beta 2 subunits of tryptophan synthase were investigated by small-angle X-ray scattering. The molecular parameters are: radius of gyration, alpha: 1.95 nm, beta 2: 3.01 nm; maximum particle diameter, alpha: 5.8 nm, beta 2: 10.5 nm; and hydrated volume, alpha: 60 nm3, beta 2 160 nm3. The shape of the alpha subunit can best be described by a circular cylinder, slightly tapered at one end. An elongated elliptical cylinder with its cross section larger in the middle than at the ends was found to be a model equivalent in scattering to the beta 2 subunits. The alpha 2 beta 2 enzyme complex was found to have a radius of gyration of 4.01 nm, a maximum length of 13.5 nm, and a hydrated volume of 270 nm3. No satisfactory fit of the scattering data was obtainable by mere apposition of the models of the alpha and beta 2 subunits. Two cylinders overlapping laterally fit the experimental data considerably better, suggesting changes in the conformation of the subunits on forming the alpha 2 beta 2 complex.

Bacterial Proteins↗