title: Interactions of purified Serratia marcescens metalloproteases with fresh human serum and with purified human serum proteins.
abstract: Exposure of fresh human serum to two purified metalloproteases of S. marcescens strains SF 178 and SH 186 (both of serotype O6/O14:H12) at 35 degrees C, 3 h, resulted in altered electrophoretic mobility of the protease inhibitors alpha 1-antitrypsin and alpha 2-macroglobulin, alpha 2-HS-glycoprotein, and complement (C) components C1q, C1s, C3a, C3c, C4, C5, and C9, but not C6, C7, C8, and properdin, as determined with electroimmunoassays (Laurell technique). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) documented the partial degradation of the heavy (H) chain of purified human immunoglobulin IgG by the metalloproteases of S. marcescens strains SF 178 and SV O1 (serotype O13/O19:H1), but not by the metalloproteases of strains SH 186 and SE 182 (serotype O9B:H11) following extended incubation (35 degrees C, 22 h). Human IgA and IgM were refractory. Purified human C components, C3, C4, C5, C6, C7, C8, and C9, as well as purified human alpha 1-antitrypsin, alpha 2-macroglobulin, transferrin, and lactoferrin were attacked by the S. marcescens metalloproteases SF 178 and SH 186 at 35 degrees C for 5 h, as demonstrated with the SDS-PAGE procedure; haptoglobin and C-reactive protein were resistant.
mesh_terms: D000209:Acute-Phase Proteins / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism*; D003165:Complement System Proteins / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D008666:Metalloendopeptidases; D011480:Protease Inhibitors / Q000378:metabolism; D012706:Serratia marcescens / Q000201:enzymology*
chemical_list: D000209:Acute-Phase Proteins; D001798:Blood Proteins; D007136:Immunoglobulins; D011480:Protease Inhibitors; D003165:Complement System Proteins; D010450:Endopeptidases; D008666:Metalloendopeptidases