We have established a refined methodology for generating surface plasmon resonance sensor surfaces of recombinant his-tagged human cyclophilin-A. Our orientation-specific stabilisation approach captures his-tagged protein under 'physiological conditions' (150 mm NaCl, pH 7.5) and covalently stabilises it on Ni2+-nitrilotriacetic acid surfaces, very briefly activated for primary amine-coupling r...

Cyclophilins have been suggested to act as leukocyte chemotactic factors produced in the course of inflammation. Therefore we looked for the presence of cyclophilins in the synovial fluids (SF) from patients with rheumatoid arthritis (RA). Peptidyl prolyl cis-trans isomerase activity (PPIase) was measured in SF from knee punctures of 26 patients with RA and five patients with knee osteoarthriti...

Microtubule assembly and disassembly is required for the maintenance of cell structure, mobility, and division. However, the cellular and biochemical implications of microtubule disruption are not fully understood. Using a proteomic approach, we found that the peptidyl-prolyl isomerase, cyclophilin A, was increased in plasma membrane extracts from chronic myeloid leukemia cells after microtubul...

Seven purified metabolites of cyclosporin G (CsG) were studied for binding to cyclophilin and a 50-kDa binding protein (50-kDa BP). The ratios of the metabolite dissociation constants with respect to CsG were compared with in vitro immunosuppression by using the primary mixed lymphocyte suppression assay. The immunosuppressive potency ratio of the parent compounds, both cyclosporin A (CsA) and ...

Cyclophilin A, the major intracellular binding protein for the immunosuppressive drug cyclosporin A (CsA), was studied in human keratinocytes during differentiation both in vivo and in vitro. Analysis of cyclophilin by gel-filtration radiobinding-assay with tritiated CsA showed one specific radioactive peak at 17 kDa. By this technique, the levels of cyclophilin (mean 55.23 +/- 8.43 pmol/mg pro...

Huntington's disease (HD) is an incurable autosomal-dominant neurodegenerative disorder initiated by an abnormally expanded polyglutamine domain in the huntingtin protein. It is proposed that abnormal mitochondrial Ca2+ capacity results in an increased susceptibility to mitochondrial permeability transition (MPT) induction that may contribute significantly to HD pathogenesis. The in vivo contri...

Antamanide is a cyclic decapeptide derived from the fungus Amanita phalloides. Here we show that antamanide inhibits the mitochondrial permeability transition pore, a central effector of cell death induction, by targeting the pore regulator cyclophilin D. Indeed, (i) permeability transition pore inhibition by antamanide is not additive with the cyclophilin D-binding drug cyclosporin A, (ii) the...

Cyclosporin A (CsA), a potent immunosuppressant, is known to bind with high specificity to cyclophilin (CyP), a 17.7 kDa protein with peptidyl-prolyl isomerase activity. In order to investigate the three-dimensional structure of the CsA/CyP complex, we have applied a variety of multidimensional NMR methods in the study of uniformly 13C-labeled CsA bound to cyclophilin. The 1H and 13C NMR signal...

Loss of fragile histidine triad (Fhit) expression is often associated with human malignancies, and Fhit functions as a tumor suppressor in controlling cell growth and apoptosis, although specific signal pathways are still undefined. We have used a proteomic approach to define proteins in the Fhit-mediated tumor suppression pathway. Because substitution of Tyr(114) (Y114) with phenylalanine (Y11...