In vitro complex formation between cholesterol and alpha 1-proteinase inhibitor.
The in vitro interaction between human alpha 1-proteinase inhibitor (alpha 1-PI) and cholesterol was studied with electrophoretic and gel chromatographic methods. The addition of cholesterol (from 1 to 20 mol/mol alpha 1-PI) at 37 degrees C resulted in retarded electrophoretic mobility of alpha 1-PI towards the anode, diminished immunoreactivity and antiproteinase activity. At a molar ratio of 2:1 (cholesterol/alpha 1-PI), antitryptic activity was reduced by 15% but antielastase activity by 50%. At this ratio the gel filtration alpha 1-PI peak appeared at 67 kDa, as compared to 52 kDa for native alpha 1-PI. No size difference was noted on SDS-PAGE. These results suggest the occurrence of noncovalent complex formation between cholesterol and alpha 1-PI in vitro.
Janciauskiene
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Department of Medicine, Malmö General Hospital, University of Lund, Sweden.
Eriksson
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D002784:Cholesterol / Q000737:chemistry*; D002850:Chromatography, Gel; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D046911:Macromolecular Substances; D011485:Protein Binding; D000515:alpha 1-Antitrypsin / Q000737:chemistry*
D046911:Macromolecular Substances; D000515:alpha 1-Antitrypsin; D002784:Cholesterol