Abstract
Type 1 pili were purified from a Klebsiella pneumoniae strain isolated from a human urinary tract infection. The pili were removed from the bacteria by mechanical shearing, precipitated out of solution by ammonium sulfate, solubilized in a deoxycholate-containing buffer, and finally purified by gel filtration. Chemical characterization of the isolated pili revealed a single protein subunit (pilin) which had a Mr = 21,500. Amino acid compositional analysis revealed a high content of residues that contribute significantly to secondary structure. Automated sequence analysis of the NH2-terminal region revealed a striking homology (79% identity) with type 1 pili of Escherichia coli. In contrast, NH2-terminal sequence comparison of K. pneumoniae pilin with other previously reported bacterial pilins showed no significant homology. No immunological cross-reactivity was detectable between E. coli and K. pneumoniae pili when tested by Ouchterlony double immunodiffusion or by rocket immunoelectrophoresis. The results of this study, when compared to other studies of bacterial pili, indicate that type 1 pili from members of the Enterobacteriaceae share morphological similarities and that their monomeric subunits are chemically similar. In addition, these results give strong evidence that the type 1 pilins of the enteric bacteria represent a separate class of homologous pilins.
Highlights
We found that higher yieldsof K. pneumoniae pili, with less contamination by membrane proteins, could be achieved by adding a filtereds,aturated solution of ammonium sulfate dropwise to a stirred suspension of pili until the final concentration reached 33% of saturation at 4 "C (23.9%)
The purification procedure used to isolate K. pneumoniae pili was a modification of the techniquepreviously described by Korhonen et al for the isolation of pili from E . coli [12] and S. typhimurium [19]
K. pneumoniae pili were shown to be morphologically intact after the purificationprocess as aqueous buffer and requiredguanidine HCl for complete dissociation
Summary
Another pili type was isolated from an E. coli strain causing human urinary Pili are composed of a monomeric nisms of E. coli and Klebsiella pneumoniae in the urinary protein subunit (pilin)that polymerizes to form a helical pilus tract [15,16,17] and Salmonella typhimuriunin the gastrointesstructure [2].Compositional analyses of several reported pilin tinal tract [18].The NHZ-terminalamino acid sequence of E .
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
