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Studies to establish a reference pattern of slime‐forming, encapsulated Streptococcus cremoris plasma membrane antigens by crossed immunoelectrophoresis
Author(s) -
Niskasaari Kaarina,
Valkonen Kaija H.,
Forsén Raili
Publication year - 1983
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.1150040306
Subject(s) - coomassie brilliant blue , antiserum , antigen , chemistry , polyacrylamide gel electrophoresis , immunoelectrophoresis , membrane , chromatography , immunoprecipitation , membrane protein , biochemistry , staining , reagent , microbiology and biotechnology , biology , enzyme , genetics , gene
The antigenic composition of the plasma membrane of the slime‐forming, encapsulated strain Streptococcus cremoris T 5 , originally isolated from the Finnish ropy sour milk product “viili”, was studied by crossed immunoelectrophoresis (CIE). Membrane proteins were solubilized with 1% Triton X‐100 extraction and mild sonication at pH 8.7. The solubilizing effect for membrane protein was investigated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Only quantitative differences were observed in the SDS‐PAGE patterns of the Triton X‐100 extracts as compared with that of the total‐protein sample. The anti‐membrane antiserum pool was collected over twelve months. The conditions for CIE were standardized using different antigen and antibody concentrations. The immunoprecipitation pattern with standard antisera was reproducible with separate membrane preparations. The solubilized membrane antigens could be stored at ‐20°C for two months with no changes in the precipitation pattern. A reference immunoprecipitation pattern with 19 precipitation lines was established for S. cremoris T 5 membrane antigens. Two immunoprecipitates had a strong staining intensity with Coomassie Brilliant Blue, and one of these was also stainable with periodate‐Schiff's reagent. Certain special characteristics of these precipitation lines are proposed for further study.