streptococcal toxinsmedical dictionary

Group of haemolytic exotoxins released by Streptococci. _ haemolysin: 26-39 Kd (four types), forms ring like structures in membranes (see Streptolysin O). Lipid target unclear. _ haemolysin: a hot cold haemolysin with sphingomyelinase C activity. _ haemolysin: complex of two proteins (29 and 26 kD) that act synergistically, rabbit erythrocytes particularly sensitive. _ toxin: heat stable peptide (5 kD) with high proportion of hydrophobic amino acids. Seems to act in a detergent like manner (c.f. Subtilysin), but may form hydrophilic transmembrane pores by cooperative interaction with other _ toxin molecules. Leucocidin (Panton Valentine leucocidin): two components f (fast migration on CM cellulose column: 32 kD) and s (slow: 38 kD). Mode of action contentious.

See: Streptococcus, streptolysins O and S, erythrogenic toxin.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)