title: Horse alpha 2-macroglobulin. Circular dichroism studies of conformational changes upon reaction with proteinases and methylamine.
abstract: The interaction of horse alpha 2-macroglobulin with methylamine, trypsin and cathepsin D was studied by circular dichroism in the far and near UV region, by polyacrylamide gel electrophoresis and by determination of its inhibitory activity. The CD spectra of horse alpha 2-macroglobulin resemble those of bovine und human alpha 2-macroglobulin. The CD spectra were changed in a different manner after the interaction of alpha 2-macroglobulin with methylamine, trypsin and inactive or active cathepsin D, indicating that more than one conformational change occurs. Cathepsin D activity was not affected by complex formation with horse alpha 2-macroglobulin. In contrast to the action of trypsin, treatment with methylamine did not increase the electrophoretic mobility of alpha 2-macroglobulin.
mesh_terms: D000818:Animals; D002402:Cathepsin D / Q000378:metabolism; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D006736:Horses; D007202:Indicators and Reagents; D011485:Protein Binding; D011487:Protein Conformation; D013056:Spectrophotometry, Ultraviolet; D014357:Trypsin / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000494:pharmacology; D000511:alpha-Macroglobulins / Q000032:analysis*
chemical_list: D007202:Indicators and Reagents; D014361:Trypsin Inhibitors; D000511:alpha-Macroglobulins; D014357:Trypsin; D002402:Cathepsin D