Biomedical subjects

P Salgam

Publications and source records attributed to P Salgam.

4 recordsLinked to original sources

PubMed1991

Structure-function studies of designed DDT-binding polypeptides.

An artificial 24-residue DDT-binding polypeptide (Moser, R., Thomas, R.M., and Gutte, B. (1983) FEBS Lett. 157, 247-251) and several analogues of this peptide were characterized by ligand binding, spectroscopic, and immunological studies. Comparison of dissociation constants showed that Phe14 and His16 were important for DDT binding and that the designed peptide had noticeable ligand specificity. Measurement of the circular dichroism of the artificial DDT-binding peptide revealed a high proportion of beta-structure which was abolished only partly by 8 M urea. When Tyr15, Tyr17, and Phe3 whose side chains were on the same side of the proposed beta-sheet were replaced by non-aromatic amino acids, the cross-reactivity with antibodies against the original DDT-binding peptide decreased stepwise. In summary, the results of this study support essential features of our structural model of the designed 24-residue DDT-binding peptide.

Amino Acid Sequence↗

PubMed1985

A crystalline synthetic peptide representing the epitope of a monoclonal antibody raised against synthetic interferon-alpha 1 fragment 111-166.

The antigenic determinant recognized by the monoclonal antibody that had been raised against synthetic human interferon-alpha 1 (IFN-alpha 1) fragment 111-166 [Arnheiter, H., Thomas, R.M., Leist, T., Fountoulakis, M., and Gutte, B. (1981) Nature (Lond.) 294, 278-280] and that cross-reacted with human IFN-alpha 1, IFN-alpha 2, and IFN-alpha A made in Escherichia coli, was localized to the region between residues 151 and 166 using synthetic COOH-terminal interferon fragments. In solid-phase radioimmunoassays neither the strongly hydrophilic COOH-terminal nonapeptide IFN 158-166 nor its mixtures with IFN 151-162 or IFN 149-158 showed any measurable interaction with the antigen binding site of the monoclonal antibody. For antibody binding, the full covalent structure of IFN 151-166 was required. Quantitatively very similar results were obtained with IFN 149-166 and IFN 143-166. The synthetic COOH-terminal hexadecapeptide of human IFN-alpha 1 (IFN 151-166) could be crystallized.

Antibodies, Monoclonal↗

PubMed1979

[Chronic polyarthritis: role of polymorphonuclear leukocytes in the destruction of pannus-free articular cartilage].

The synovial fluid (SF) of RA patients contains large amounts of PMN which are well equipped with neutral enzymes to degrade articular cartilage: elastase and cathepsin G, which both destroy proteoglycans and native collagen, as well as 2 types of collagenoases. Indirect evidence suggests that PMN might be important in the destruction of RA articular cartilage. In 19 SF of RA patients no free elastase or collagenase was found. Using immune histochemical methods, we observed that PMN and macrophages of SF contain both elastase and alpha 1-anti-trypsin and alpha 2-macroglobulin. Peripheral PMN - but not monocytes - contain elastase, however both types of cells lack alpha 1-antitrypsin and alpha 2-macroglobulin. Elastase is demonstratable in the superficial layer of pannus free RA articular cartilage. These findings suggest that neutral proteinases from PMN in RA SF are generally neutralized by physiologic inhibitors and removed by phagocytes. The enzyme-inhibitor interaction might be bypassed during "frustrated phagocytosis" so that enzymes like PMN elastase can damage RA articular cartilage.

Arthritis, Rheumatoid↗

PubMedDate not supplied

Purification and some properties of collagenase proenzyme activator from rheumatoid synovial fluid.

1. An activator of leucocyte latent collagenase has been extracted from rheumatoid synovial fluid by a preparative method consisting of six steps including precipitation by ammonium sulphate and chromatography on Sephadex G-100, QAE-Sephadex and SP-Sephadex C-50. The purification factor was nearly 1000 and the activator isolated could be shown to have a high degree of homogeneity.--2. Gel chromatography indicated a molecular weight of ca. 60 000.--3. Kinetic studies of the activation and inactivation of the activator during incubation at higher temperatures demonstrated its enzymic nature.--4. Activation of latent collagenase was partially inhibited by iPr2P-F and KCN. Soybean trypsin inhibitor, iodoacetamide, TosLysCH2Cl and TosPheCH2Cl had no effect.--5. Leucocyte latent collagenase was also activated by an excess of trypsin and p-hydroxymercuribenzenesulphonic acid, but only to the extent of about 40% of its activation capacity. Purified neutral protease from human leucocyte granules had no effect on latent collagenase.--6. Several typical substrates for proteases, peptidases, esterases and glycosidases were not attacked by the activator. The possibility that the activator is a known enzyme, such as kallikrein, urokinase or cathepsin B1, could be excluded.

Arthritis, Rheumatoid↗