Open AccessAlbumin-binding proteins on the surface of the Streptococcus milleri group and characterization of the albumin receptor of Streptococcus intermedius C5
Author(s) -
Mark Willcox,
Margaret Patrikakis,
Ching-Yee Loo,
K. W. Knox
Publication year - 1993
Publication title -
journal of general microbiology/journal of general microbiology
Language(s) - English
Resource type - Journals
eISSN - 2059-9323
pISSN - 0022-1287
DOI - 10.1099/00221287-139-10-2451
Subject(s) - albumin , antiserum , biology , group a , polyclonal antibodies , streptococcus , plasma protein binding , streptococcus milleri , biochemistry , bovine serum albumin , cell wall , microbiology and biotechnology , antigen , bacteria , immunology , medicine , genetics
Members of the Streptococcus milleri group (SMG) that react with Lancefield group C antisera were shown to bind large amounts of albumin although there was no direct relation between these two properties as polyclonal antisera to Lancefield group C antigen did not prevent the binding of albumin. There was a specificity for albumin binding, with albumin from man, monkeys, cat, dog and mouse being bound to a greater degree than albumin from cow, horse, goat or rabbit. Gold-labelled albumin was shown to be located close to the surface of strains by transmission electron microscopy. A cell-surface protein of M(r) 24,000, which was liberated by lysozyme treatment of cells, was shown to be the cell-surface receptor on Streptococcus intermedius C5. The receptor was physically dissimilar from protein G, an albumin- and IgG-binding protein of 'large-colony' Lancefield group C and G streptococci.