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J Hönes

Publications and source records attributed to J Hönes.

9 recordsLinked to original sources
PubMed1989

Quantitative immunohistochemistry: standardization and possible application in research and surgical pathology.

We describe three different methods of calibration of quantitative immunohistochemistry, two of them based on self-made dye-agarose or antigen-agarose substrates. Quantification of immunostained objects (immunosignals) can be done by (1) microscope photometry (plug method) or scanning-photometry; (2) and densitometry of a television transformed microscope image. Both approaches are subjected to the different methods of calibration and three examples of application.

Arginase↗
PubMed1988

Immunophotometric quantification of extravascular immunoglobulin deposits in the synovial membrane of patients with osteoarthritis and rheumatoid arthritis.

The amount of extravascular immunoglobulin deposits in the synovial membrane of patients with osteoarthritis and rheumatoid arthritis was studied in comparison with that of patients suffering from non-joint diseases. Immunoglobulin deposits were immunostained using the three-layer immunoperoxidase method. The staining results were quantified with the help of a microscope photometer connected with a scanning stage. Several experiments involving artificial test substrates, diseases with allegedly increased extravascular deposits or diseases not exhibiting extravascular deposits of immunoglobulins are used to validate the described microspectrophotometrical approach for measuring extravascular immunoglobulin deposits. The scanning photometry demonstrates significantly higher amount of extravascular immunoglobulin deposits in rheumatoid arthritis as compared with osteoarthritis and non-joint diseases.

Arthritis, Rheumatoid↗
PubMed1987

An integrated prediction of secondary, tertiary and quaternary structure of glucose dehydrogenase.

Based on homology of partial sequences, on physico-chemical evidence and on studies using chemical modification, we came to the tentative conclusion that tetrameric glucose dehydrogenases from Bacillus megaterium and B. subtilis should have a structure closely related to that of lactate dehydrogenase. The overall homology of primary structures was found to be very low, however, and independent predictions of secondary structure produced a clearly different pattern of beta-strands and alpha-helices. We nevertheless tried a manual prediction based on the hydrophobic nature of internal beta-sheet and on the amphiphilic character of external helices. This treatment led to the identification of analogues of all the beta-strands present in lactate dehydrogenase with the exception of beta C. Six amphiphilic helices were identified corresponding to alpha B, alpha C, alpha D, alpha 1F, alpha 2F and alpha 3G in lactate dehydrogenase. Conserved functional residues were found at analogous positions. The Q and R intersubunit contacts could be identified and partial proteolysis was found to occur on the outer surface of the tetramer. The structure was found to explain the better binding of NADP as compared to NAD+ and offered a rationalization of the role of the essential lysine at position 201.

Amino Acid Sequence↗
PubMed1986

Studies of enzyme-ligand complexes using dynamic fluorescence anisotropy. II. The coenzyme-binding site of malate dehydrogenase.

The coenzyme-binding site in mitochondrial malate dehydrogenase from pig heart was studied using dynamic fluorescence anisotropy decay. The dynamics of the fluorescent ligands NADH and 6-cyano-7-hydroxy-4,8-dimethylcoumarin were used to detect conformational changes at the dihydronicotinamide-and at the adenosine-binding sites, respectively. Addition of the natural substrate L-malate to the complex from enzyme and NADH does not influence the complete immobilization of the dihydronicotinamide group, whereas the stereoisomer D-malate and the substrate-analogue hydroxymalonate form ternary complexes with highly mobile dihydronicotinamide. The dynamics of the fluorescent adenosine-analogue are not influenced by formation of complexes with substrate and substrate-analogues. Thus the conformational changes at the dihydronicotinamide-binding site remain local and are not transmitted to the adenosine-binding site.

Adenosine↗
PubMed1986

Studies of enzyme-ligand complexes using dynamic fluorescence anisotropy. I. The substrate-binding site of malate dehydrogenase.

The substrate binding site of pig mitochondrial malate dehydrogenase was characterized using complexes of the enzyme with the substrate analogue 8-hydroxypyrene-1,3,6-trisulfonate with and without the addition of coenzymes. The rotational mobility of the fluorescent dye within the binding site was examined with the aid of a multi-frequency phase-fluorimeter. Together with absorption, circular dichroism and fluorescence spectroscopy, conformational changes of the substrate binding site could be defined. The dye was generally found to be immobilized in the binding site. Addition of NADH to the binary complex caused strengthening of a hydrogen bond and further loss of mobility, whereas NAD enlarged the space available for motion of the dye with concomitant loss of the hydrogen bridge.

Animals↗
PubMed1985

Ligand binding and stabilization of malate- and lactate dehydrogenase.

Binding of coenzymes, coenzyme fragments and phenolate ligands to malate- and lactate dehydrogenase was studied. From linear competition in titration experiments, the coenzyme binding site was concluded to bind all the ligands employed. The analogy between the phenolate ligands and tetraiodofluorescein which is known to bind at the adenosine binding site suggests binding of phenolates at this site. Coenzymes and coenzyme fragments retard the irreversible thermal inactivation of the enzymes. The retardation effect decreases in the order NADH greater than NAD greater than ADPR greater than or equal to AMP for both enzymes. Phenolate ligands binding to the adenosine pocket do not stabilize the enzymes. The stabilization is concluded to originate from the interaction of coenzyme phosphate and nicotinamide with the enzymes. The interactions with the adenosine moiety and with the second ribose seem to be ineffective in retardation of thermal denaturation.

Adenosine Monophosphate↗
PubMed1985

Chemical modification of the essential arginine in malate dehydrogenases.

Chemical modification of arginine in malate dehydrogenases from pig heart mitochondria and from Bacillus subtilis was done using 4-hydroxy-3-nitrophenylglyoxal. Incorporation of 2 reagent molecules per subunit was observed concomitantly with complete loss of enzymatic activity. Partial protection was obtained with a substrate analogue and by formation of abortive ternary complexes, whereas coenzyme alone did not inhibit the inactivation. Modified inactive enzymes formed binary complexes with coenzyme as well as the ternary complex with NAD/sulfite. The substrate analogue 8-hydroxy-1,3,6-pyrenetrisulfonate was bound with reduced affinity, however. Because of the known stoichiometry of two reagent molecules per arginine we conclude that one arginine essential for substrate binding was modified in both enzymes.

Animals↗
PubMedDate not supplied

[Development of a new quantitative rheumatoid factor test].

A new simple identification of rheumatoid factor on nitrocellulose was developed that allows quantitative detection. Verification of the results was done by comparison with the established Waaler-Rose-Test and Latextest: Correlation coefficient of linear regression for Latextest rLR = 0.717 and for Waaler-Rose-Test rLR = 0.665; Spearman rank correlation coefficient for Latextest rs = 0.798 and for Waaler-Rose-Test rs = 0.700. The interday and intraday variations showed good results. The histograms for different patient groups showed significant distributions. The nitrocellulose-test satisfies ARA-criterium No. 6.

Adult↗