Formation and Isolation of Leucocidin from Pseudomonas aeruginosa

Identification of the lipopolysaccharide core region as the receptor site for a cytotoxin-converting phage, phi CTX, of Pseudomonas aeruginosa

“…Unlike other toxins and enzymes produced by P. aeruginosa, cytotoxin is not secreted into the culture medium. It is produced as a cell-associated procytotoxin, released into the medium during cell lysis, and then converted to an active cytotoxin by C-terminal processing (8,9,31).In previous studies (6,7,11), it was found that the gene encoding cytotoxin, clx, existed only in two of about 400 P. aeruginosa strains from various sources and that in both strains the genes existed on the genomes of the prophages. Furthermore, both of the bacteriophages isolated, which were phylogenetically closely related to each other (11), actually converted P. aeruginosa strains to cytotoxin producers by their lysogenization (7, 11).…”

Crystallization and Some Properties of Leukocidin from Pseudomonas aeruginosa

“…These values calculated for the molecular weight of the leukocidin which we obtained were larger than that of Scharmann's leukocidin (Mr=27,500) and Lutz's leukocidin (Mr=25,100). The discrepancy among the molecular weights of leukocidin obtained from P. aeruginosa is less well understood, but these differences may depend on the methods used for preparation and purification since Scharmann pointed out the requirement of partial degradation of leukocidin by autolytic enzymes of Pseudomonas for the release of the toxin bound to subcellular structures of the bacteria into the medium (18). Lutz reported the amino acid composition of leukocidic toxin of P. aeruginosa, in which 212 residues of amino acid and only traces of cysteine were detectable (11).…”

“…P. aeruginosa 158 used in this study was shown to produce leukocidin by Scharmann (18)(19)(20)(21)(22) and kindly supplied by Lutz, Institute of Pharmacology and Toxicology, Justus-Lieberg-University. The microorganisms were grown on a trypticase soy broth medium containing 0.5% glucose with a reciprocal shaker (120 cycles/min) at 30 C for 12 hr.…”

“…The leukocidin of Pseudomonas aeruginosa was firstly described in 1976 by Scharmann (18) and showed a striking resemblance to the biological activity ofstaphylococcal leukocidin (13)(14)(15)(16)26) inflicting a series of morphological changes on rabbit leukocytes but not on rabbit erythrocytes. However, the differences of the mode of toxic actions of these leukocidins were enormous.…”

“…Although most of our knowledge concerning the leukocidin of P. aeruginosa comes from the studies of Scharmann (18)(19)(20)(21)(22) and Lutz (11), the mode of cytotoxic action at the molecular level is still not understood. In the present paper, we described a procedure for purification and crystallization of pseudomonal leukocidin with good reproducibility differing from the method of Scharmann (18) and Lutz (11) based on solubilization of the toxin from its ammonium sulfate precipi ta te.…”