RT Journal Article SR Electronic(1) A1 Lämmler, Christoph A1 Frede, Christopher A1 Gürtürk, Kemal A1 Hildebrand, Axel A1 Blobel, HansYR 1988 T1 Binding Activity of Streptococcus canis for Albumin and Other Plasma Proteins JF Microbiology, VO 134 IS 8 SP 2317 OP 2323 DO https://doi.org/10.1099/00221287-134-8-2317 PB Microbiology Society, SN 1465-2080, AB All 24 cultures of Streptococcus canis examined bound 125I-labelled human albumin, IgG and fibrinogen; but neither IgA nor haptoglobin. Binding of human albumin was time-dependent, saturable and reversible by the addition of unlabelled albumin. The binding of 125I-labelled human albumin could be inhibited completely by unlabelled albumin preparations from humans, mice and dogs, and partly by bovine albumin. In contrast, binding of 125I-labelled human albumin was not inhibited by unlabelled rabbit albumin, human IgG or human fibrinogen. Data from competition experiments of two S. canis cultures with high 125I-labelled albumin-binding activities yielded K D values of 10 and 15 nmol l−1, respectively. The estimated number of binding sites per bacterial cell ranged from 30000 to 57000. The binding factor for albumin could be isolated from S. canis by boiling the bacteria at pH 2, and it was purified by affinity chromatography on human albumin-Sepharose. The isolated albumin-binding proteins had a molecular mass of approximately 51 kDa and inhibited binding of 125I-labelled albumin to S. canis. They formed complexes with human albumin that altered its electrophoretic mobility., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-134-8-2317