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S Baudner

Publications and source records attributed to S Baudner.

11 recordsLinked to original sources
PubMed1992

Differential expression of the two methyl-coenzyme M reductases in Methanobacterium thermoautotrophicum as determined immunochemically via isoenzyme-specific antisera.

Methanobacterium thermoautotrophicum contains two isoenzymes of methyl-coenzyme M reductase (MCR), MCR I and MCR II, which catalyze the methane-forming step and which together represent more than 10% of the cellular protein. We describe here the preparation of isoenzyme-specific antisera against the two MCR isoenzymes and their use in the quantitative immunochemical determination of the two isoenzymes in the methanogen. The relative and absolute cellular concentration of the two proteins is shown to be strongly affected by growth conditions such as the temperature, pH, and substrate concentration. Conditions were found yielding cells which contained essentially only MCR I or MCR II. Using antisera against MCR I and MCR II, MCR from other methanogens were immunochemically compared. Evidence is presented that Methanobacterium wolfei also contains two isoenzymes of MCR.

Immune Sera↗
PubMed1991

Measurement signal versus value in immunoassays for human plasmaproteins.

Signal size proportionality to a measurement value will be obtained in immunoassays only if the following four--theoretical--postulates are fulfilled: The immunochemical reaction behaviour (number and affinity of the epitopes) of the protein analyzed is identical and uniform for both the reference preparations (Standard/Calibrator/Control) and for the analyte in the specimens (uniform physicochemical properties of the proteins). The immunochemical reaction behaviour of the antibody/ies containing reagent used in the immunoassay is identical and uniform from batch to batch with respect to the reactive antibody population. The immunochemical method is so well standardized with the consequence that the size of the measurement signal--caused only by the antigen antibody reaction product--will not be falsified (by matrix- and other interfering influences, or by the method principle). The values for the results of plasma protein determination are declared by arbitrary units, e.g. international units (IU). As a rule conversion factors to g/L (SI units) are not constant and depend on very many effects. It is very difficult to fulfill all the four theoretical postulates. Therefore the practical consideration of the medical requirements should be taken into account and should be the guideline for approachable solutions.

Antibodies↗
PubMed1990

[Problems in standardization of the immunochemical detection of plasma proteins. I. International reference standards for plasma proteins. II. Immunochemical relation of measurement signals and values].

When the results of plasmaprotein determination--dependent on the reagents, methods and other factors--are expressed in international units (IU) a better comparison of the results between different labs is possible. By this means and using the corresponding reference values and reference intervals the reliability of the interpretation of laboratory data will increase. The situation regarding the WHO IRP's for plasma proteins (approx. 20 parameters) and the relation from IU to mg in the reagents of the Behringwerke AG are reported. The overlability of WHO IRP's has not allowed yet to achieve an optimal standardization of the immunochemical methods for measurement of plasma proteins. This depends especially on the complexity of the antigen-antibody reaction. The relationship between the measured signal and the hence obtained value will be discussed in details in the second part of this paper. Hereby especially the reciprocal interdependence between physicochemical properties of proteins and the deriving immunochemical behaviour as well as the dependence of the results from the quality of the antibodies-containing reagents are also considered. Possible solutions for a better control system of the plasma protein determination by using the so called master calibrators as internal support for validation will be presented. Furthermore, general immunochemical postulates and rules for optimization of the standardization of plasma protein determination will be proposed and discussed.

Antigen-Antibody Complex↗
PubMed1989

Unusually high concentrations of Zn alpha 2-glycoprotein and the lack of alpha 2HS-glycoprotein in human ejaculates.

Ejaculates of 132 nonvasectomized and 129 vasectomized men were assayed for their Zn alpha 2- and alpha 2HS-glycoprotein contents by radial immunodiffusion. The respective mean concentrations of Zn alpha 2-glycoprotein were 319 and 309 mg/L, respectively, but these fluids were devoid of alpha 2HS-glycoprotein. In comparison, the concentration of these two proteins in serum of normal men were 62 and 617 mg/L for Zn alpha 2- and alpha 2HS-glycoprotein, respectively. Because albumin in the ejaculates is 100-fold less concentrated than in serum, the fivefold increase in the concentration of Zn alpha 2-glycoprotein of the ejaculates represents about a 500-fold enrichment of this protein in the ejaculates over the concentration expected by comparison with albumin.

Adult↗
PubMed1988

Purification and characterization of a plasminogen activator inhibitor 1 binding protein from human plasma. Identification as a multimeric form of S protein (vitronectin).

A binding protein for plasminogen activator inhibitor 1 (PAI-1-BP) was isolated from human plasma by a four-step procedure. 1) The 7 S globulin fraction of plasma was isolated by gel filtration on Sephacryl S-300. 2) Human endothelial cell-type plasminogen activator inhibitor (PAI-1), pretreated with 12 M urea, was added to this fraction (22 micrograms of PAI-1/ml of plasma), and a PAI-1 antigen peak with apparent mass 450 kDa (representing 65% of PAI-1 antigen and 85% of PAI activity) was isolated by gel filtration of this mixture. 3) The PAI-1.PAI-1-BP complex was further purified by immunoadsorption on an immobilized murine monoclonal antibody directed against PAI-1 (MA-7D4) and by elution with 4 M KSCN. 4) The complex was then dissociated by addition of excess human tissue-type plasminogen activator (t-PA), and t-PA and PAI-1 antigen (t-PA.PAI-1 complexes and free t-PA and PAI-1) were removed by immunoadsorption on monoclonal antibodies directed against t-PA (MA-62E8) and against PAI-1 (MA-7D4 and MA-12A4). Sodium dodecyl sulfate-gel electrophoresis of the purified material under nonreducing conditions revealed two bands with apparent mass approximately equal to 150 kDa and two bands with mass 74 and 68 kDa. Reduced sodium dodecyl sulfate-gel electrophoresis displayed two main bands with apparent masses of 73 and 64 kDa. The PAI-1-BP reacts with urea-treated, but not with inactive PAI-1. t-PA dissociates the complex between PAI-1 and PAI-1-BP. PAI-1 in complex with PAI-1-BP is 2-3-fold more stable at 37 degrees C than purified PAI-1, suggesting that PAI-1-BP may stabilize PAI-1 in blood. The concentration of PAI-1-BP in plasma determined by titration with PAI-1 is approximately 130 mg/liter. The isolated PAI-1-BP was shown to be identical to S protein (vitronectin) both by cross-reactivity with monospecific rabbit antisera and by NH2-terminal amino acid sequence analysis. The gel filtration behavior, mobility on sodium dodecyl sulfate-gel electrophoresis, and concentration in plasma suggest that PAI-1-BP is a multimer (presumably a dimer) of S protein accounting for approximately 35% of the S protein in plasma.

Amino Acids↗
PubMed1979

A new method for fluorescence immunoassay using plane surface solid phases (FIAPS).

A method distinguished by high sensitivity, low non-specific binding, easy handling, and broad applicability with respect to various antigens is described. Films of polymethyl-methacrylate with plane surfaces were selected as solid phase for adhesive or covalent binding of different antigens (DNA, histone, human, rabbit or goat immunoglobulins). Proteins were covalently bound to the films by the azide method (Orth and Brummer, 1972). Polymethylmethacrylate films thus coated had a negligible autofluorescence and gave minimal non-specific binding of protein. Coated films were used for specificity control of FITC-labeled antibody preparations and in the double antibody and sandwich techniques for detection of antibodies or antigens in sera from man, rabbit and goat. FITC-conjugated hyperimmune antibody, in some cases purified by immunoadsorption was used as second antibody in indirect techniques. The amount of fluorescent-labeled antibody bound per unit of surface area of film was measured by incident light with a Zeiss-Axiomat fluorescence microscope equipped for fluorescence photometry and an uranyl acetate glass plate was used as a standard. The technique appears superior to present methods of quantitative immunofluorescence analysis.

Animals↗
PubMed1977

Determination of nomifensine by a sensitive radioimmunoassay.

1. A radioimmunoassay (RIA) has been developed for determination of both nomifensine and total nomifensine (nomifensine + conjugated nomifensine) in serum, plasma, and urine. 2. Antibodies were prepared in rabbits by immunization with N-(8-Nomifensine) succinamic acid-bovine serum albumin. 3H-labelled drug was used as tracer. Separation of free from antibody-bound nomifensine was carried out using dextran-coated charcoal. For determination of total nomifensine, the acid-labile conjugate was split by acidification. 3. The limit of detection for nomifensine is 300 pg/ml plasma and the cross-reactivity of the metabolites is less that 1%. The influence of conjugated nomifensine on the results of nomifensine can be corrected. 4. Pharmacokinetics of nomifensine were determined in healthy volunteers after oral administration of 100 mg 14C-labelled drug. Peak levels of 14C radioactivity (2,150 ng/ml), total nomifensine (1,252 ng/ml) and nomifensine (53 ng/ml) appeared within 1.5-2 h; the half-life of elimination from plasma was 1.5-2 hours. The advantages of this routine method are high sensitivity, the requirement of small amounts of plasma, and simple handling.

Administration, Oral↗
PubMed1977

[Isolation and characterization of an unknown, leucine-rich 3.1-S-alpha2-glycoprotein from human serum (author's transl)].

This article describes the isolation and characterization of a previously unknown, leucine-rich 3.1S-alpha2-glycoprotein from human serum. The starting material was Supernatant II, which is a byproduct in the large-scale preparation of albumin and gamma-globulin by the ethacridine lactate/ammonium sulfate procedure. The purified protein is homogenous both in carrier-free and molecular-sieve electrophoresis. Its electrophoretic mobility indicates that it belongs to the alpha2-globulins. Isoelectric focussing splits it into 4 bands with isoelectric points between 3.8 and 4.1. In the ultracentrifuge it sediments in a single band at 3.1S. The molecular weight determined by equilibrium sedimentation is 49 600 +/- 4 000. Subunits were not detected. Chemical analysis reveals it to be a glycoprotein with a carbohydrate content of 23%. The amino acid content is unusual in that the leucine content is almost 17%, i.e. about every fifth amino acid is a leucine. The average concentration of the leucine-rich 3.1S-alpha2-glycoprotein in human serum was determined by a quantitative immunological method as 2.1 mg per 100 ml. The protein is not related to any of the previously known well characterized serum proteins.

Alpha-Globulins↗
PubMed1975

[Isolation of beta2-microglobulin from human colostrum (author's transl)].

The beta2-microglobulin from human colostrum was purified by a combination of ordinary protein-chemical techniques: gel filtration, ion-exchange chromatography and zone electrophoresis. The procedure is organized in such a way that the simultaneous isolation of many other milk proteins is possible. The beta2-microglobulin obtained from colostrum cannot be distinguished by physical-chemical or immunological means from the beta2-microblobulin isolated from the urine of patients with kidney-tubule diseases. At the beginning of lactation, human milk contains significantly more than 10 mg/-100 ml beta2-microglobulin, but the concentration drops within two or three days to 15-30% of the original amount.

Beta-Globulins↗