1. The plasma of guinea pigs treated by injections of rat sarcoma exhibits a toxic action in tissue culture preparations on the cells of both rat sarcoma and rat embryo skin. Similarly, the plasma of guinea pigs immunized by injections of rat embryo skin is toxic for cells of both types. 2. Injection of rat blood immunizes against both sarcoma and embryo skin, although not so strongly as inject...

Cardiotoxins (cytotoxins, CT) are β-structured proteins isolated from the venom of cobra. They consist of 59-61 amino acid residues, whose antiparallel chains form three 'fingers'. In contrast to neurotoxins with an overall similar fold, CTs are amphiphilic. The amphiphilicity is caused by positively charged lysine and arginine residues flanking the tips of the loops that consist primarily of h...

RTX cytotoxins play an important role in virulence of numerous gram-negative pathogens. Unexpectedly, however, we show here that the RTX proteins of Neisseria meningitidis are dispensable for virulence in the infant rat model of infection.

The Shiga toxigenic Escherichia coli (STEC) O113:H21 strain 98NK2, which was responsible for an outbreak of hemolytic uremic syndrome, secretes a highly potent and lethal subtilase cytotoxin that is unrelated to any bacterial toxin described to date. It is the prototype of a new family of AB 5 toxins, comprising a single 35-kilodalton (kD) A subunit and a pentamer of 13-kD B subunits. The A sub...

1. Theoretically, the method of cultivating tissues outside the body offers an ideal technique for the demonstration and study of cytotoxins. 2. Mouse sarcoma, which grows vigorously in the plasma of normal rats, shows little or no activity in the plasma of rats immunized by mouse sarcoma injections. 3. Rat sarcoma, readily cultivated in the plasma of normal guinea pigs, either remains quite in...

Clostridial glucosylating cytotoxins inactivate mammalian Rho GTPases by mono-O glucosylation of a conserved threonine residue located in the switch 1 region of the target protein. Here we report that EhRho1, a RhoA-like GTPase from the protozoan parasite Entamoeba histolytica, is glucosylated by clostridial cytotoxins. Recombinant glutathione S-transferase-EhRho1 and EhRho1 from cell lysate of...

(1) The cytotoxins are not specific. (2) The changes occurring after the injection of different cytotoxins are similar and do not vary in kind. (3) The changes do, however, vary in degree in the following order, the one having the most marked effect being placed first, etc.: (a) Haemolymphotoxin, (b) Splenotoxin, (c) Lymphotoxin, (d) Endotheliotoxin, (e) Nephrotoxin, (f) Hepatotoxin. (4) Nephro...