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P M Heegaard

Publications and source records attributed to P M Heegaard.

26 records · Page 2Linked to original sources
PubMed1992

Changes in serum glycoprotein glycosylation during experimental inflammation in mice are general, unrelated to protein type, and opposite changes in man and rat: studies on mouse serum alpha 1-acid glycoprotein, alpha 1-esterase, and alpha 1-protease inhibitor.

Using the method of crossed affinity immunoelectrophoresis with concanavalin A in combination with digital image processing, unrelated serum glycoproteins from normal mice and from mice undergoing an experimentally induced inflammation were analyzed for their carbohydrate-derived microheterogeneity profile. This profile changed in a generalized way in mouse serum samples taken at various time intervals after the initial induction of inflammation. The changes are not related to the acute-phase behavior of the protein itself (be it positive, negative, or nonreacting), and they are opposite to the changes in microheterogeneity profiles reported previously for glycoproteins during the acute phase in human and rat sera. These findings are discussed in the context of the biosynthetic control of glycoprotein glycosylation during the acute-phase response.

Acute-Phase Reaction↗
PubMed1992

Iscom immunization with synthetic peptides representing measles virus hemagglutinin.

Synthetic peptides representing the measles virus (MV) hemagglutinin (MVH) were incorporated into immunostimulating complexes (iscoms) and used for immunization of rabbits. Nine regions of MVH were selected on the basis of hydropathy and antigenicity profiles, by use of the known primary structure of MVH. Six linear and three branched types of peptides were synthesized and conjugated to palmitic acid before incorporation into the iscom structure. Five of the anti-peptide sera reacted by ELISA with the homologous peptide but did not react with MV in the native state, indicating that either the selected sites are not represented on the surface of MV, or they could be a conformational epitope. Human-anti MV and rabbit anti-MV did not react with the peptides.

Amino Acid Sequence↗
PubMed1991

Thiophilic adsorption chromatography: the separation of serum proteins.

Human serum proteins were separated on a matrix obtained by reaction of beta-mercaptoethanol with divinyl sulfone-activated agarose (the so-called T-gel). Binding of almost all serum proteins was observed at high concentrations of ammonium sulfate. Elution was achieved by gradually lowering the concentration of salt in the washing buffer. Fractions obtained during elution were analyzed by fused rocket immunoelectrophoresis. Proteins were recovered in high yields and with an excellent separation in this one-step procedure ("Thiophilic adsorption chromatography"). A rapid and straightforward procedure giving essentially pure immunoglobulins from crude rabbit serum with at least 80% yield by the T-gel is also presented.

Adsorption↗
PubMed1989

Concanavalin A crossed affinity immunoelectrophoresis and image analysis for semiquantitative evaluation of microheterogeneity profiles of human serum transferrin from alcoholics and normal individuals.

The microheterogeneity profile of human serum transferrin from normal and alcoholic subjects was investigated qualitatively and quantitatively by means of Concanavalin A crossed affinity immunoelectrophoresis and an image analysis program. Differences in amounts of nonreacting transferrin molecules were found, suggesting an increase in triantennary glycosylation of transferrin from alcoholics compared with normal individuals. The increased amount of a highly retarded fraction in crude sera from alcoholics was demonstrated to be artefactual, probably due to entrapment or coprecipitation as the fraction disappeared after repeating the analysis with immunosorbent-purified transferrin. In conclusion, affinity electrophoresis represents a simple approach for demonstration of variations in the neutral monosaccharides of glycans and can discriminate between transferrin from alcoholics and normal individuals.

Adult↗
PubMed1989

Real time monitoring of acylations during solid phase peptide synthesis: a method based on electrochemical detection.

Monitoring of acylation reactions during solid phase peptide synthesis is important to ensure high coupling yields in all steps of the synthesis. We describe in this paper a simple and reliable method for monitoring the time course of the acylation steps as well as the washing and deprotection steps during computer-controlled solid phase peptide synthesis. The method is based on the continuous measurement of electrical conductivity in the reaction vessel. It is shown that there is a close correspondence between the degree of acylation (as determined from the amount of 9-fluorenylmethoxycarbonyl- (Fmoc) groups released during deprotection) and the conductivity profile obtained during coupling of the amino acids to the growing peptide chain. The measurements are fed back to the computer providing data for software control of the duration of the acylation, deprotection and washing steps. The method is demonstrated with pentafluorophenol esters, but is equally applicable to dihydroxybenzotriazole esters and symmetric anhydrides using the Fmoc-polyamide strategy in a continuous flow set-up with dimethylformamide (DMF) as the general solvent.

Acylation↗
PubMed1988

Heterogeneity in copper and glycan content of ceruloplasmin in human serum differs in health and disease.

Crossed immunoelectrophoresis of human serum revealed two heterogeneity types of ceruloplasmin with different electrophoretic migration. The two types both consisted of peptides with Mr 150,000, 100,000 and 45,000, which were interpreted as native ceruloplasmin and two hydrolytic fragments. The two types were different in copper content, and one type could reversibly be changed into the other. The glycan microheterogeneity of ceruloplasmin was analyzed by crossed affinoimmunoelectrophoresis with free Lens culinaris agglutinin (LCA) and wheat germ agglutinin (WGA). A third of the ceruloplasmin molecules, both high and low copper type, bound to LCA and two thirds to WGA. The heterogeneity and the microheterogeneity of ceruloplasmin in two groups of patient sera were compared to sera from healthy individuals. The ceruloplasmin type with respect to copper content was a much better factor than either glycan microheterogeneity or total serum concentration in discriminating between the three groups.

Ceruloplasmin↗
PubMedDate not supplied

Practical multipeptide synthesis: dedicated software for the definition of multiple, overlapping peptides covering polypeptide sequences.

A personal computer program for the conversion of linear amino acid sequences to multiple, small, overlapping peptide sequences has been developed. Peptide lengths and "jumps" (the distance between two consecutive overlapping peptides) are defined by the user. To facilitate the use of the program for parallel solid-phase chemical peptide syntheses for the synchronous production of multiple peptides, amino acids at each acylation step are laid out by the program in a convenient standard multi-well setup. Also, the total number of equivalents, as well as the derived amount in milligrams (depend-ending on user-defined equivalent weights and molar surplus), of each amino acid are given. The program facilitates the implementation of multipeptide synthesis, e.g., for the elucidation of polypeptide structure-function relationships, and greatly reduces the risk of introducing mistakes at the planning step. It is written in Pascal and runs on any DOS-based personal computer. No special graphic display is needed.

Amino Acid Sequence↗