K99 surface antigen of Escherichia coli: purification and partial characterization - PubMed (original) (raw)
K99 surface antigen of Escherichia coli: purification and partial characterization
R E Isaacson. Infect Immun. 1977 Jan.
Abstract
K99, a presumed colonizing factor of enterotoxigenic Escherichia coli of calf origin, has been purified. K99 was removed from K99+ bacteria by salt extraction and subsequently purified by ammonium sulfate precipitation and column chromatography on diethylaminoethyl-Sephadex. The purified material was homogenous in size, having an s20,w of 13 to 15 S. It was composed of two subunits: a major component with a molecular weight of 22,500 and a minor component of 29,500. When observed in the electron microscope, K99 appeared to be rod-shaped, with a strong tendency for self-aggregation. At concentrations where aggregation was minimized, individual rods were observed with diameters of 8.4 nm and mean lengths of 130 nm. Based on the subunit structure, exterior location, and rod-like shape of K99, it is concluded that K99 is a pilus or pilus-like structure. Chemically, K99 is composed primarily of protein and has an isoelectric point of greater than 10. Purified K99 did not hemagglutinate guinea pig erythrocytes.
References
- Am J Vet Res. 1976 Sep;37(9):1025-9 -PubMed
- Acta Pathol Microbiol Scand B. 1975 Feb;83(1):31-6 -PubMed
- Infect Immun. 1975 Sep;12(3):656-67 -PubMed
- Infect Immun. 1976 May;13(5):1369-77 -PubMed
- Infect Immun. 1976 Apr;13(4):1117-9 -PubMed
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