Studies on hemolysis of hemolysin produced by Synechocystis sp. PCC 6803

Abstract

Hemolysin produced by various bacteria, may destroy erythrocyte membranes via a pore-forming mechanism, a detergent action, or a lipase activity. Previous to this experiment, the mode of action used by cyanobacterial hemolysin had not been reported. To characterize the action mode of hemolysin produced by the wild-type strain of Synechocystis sp. PCC6803, hemolysis of erythrocytes originating from human, mouse, sheep, rabbit and goldfish was studied. The erythrocytes of mouse, sheep and rabbit were sensitive, while those of human and fish were resistant, to this hemolysin. Using rabbit erythrocytes, it was shown that hemolysis occurred in two steps: a binding step within the first 10 min of treatment and a lytic step after 30 min. Both binding and lysis were highly temperature-dependent. Effects of erythrocyte density on hemolysis suggest that the hemolysin might target erythrocytes via a multiple-hit mechanism. In the osmotic protection experiment, all tested osmotic protectants, with molecular diameters ranging from 0.9 −5.66 nm, failed to effectively inhibit hemolysis. Scanning electron micrographs showed that the hemolysin caused protuberances or echinocytes in rabbit erythrocytes, and then disrupted and ruptured the erythrocytes. Characteristics of hemolysis showed distinct differences from other pore-forming mechanisms, suggesting that this hemolysin might act through a detergent-like or lipase mechanism, rather than a pore-forming mechanism.

Erythrocyte Lysis and Xenopus laevis Oocyte Rupture by Recombinant Plasmodium falciparum Hemolysin III

“…In addition, the protectants can allow estimation of the size of pores present in erythrocyte membranes created by pore-forming hemolysin. Osmotic protectants with hydrodynamic radii equal to or larger than those of the pores can block the pores effectively and thus prevent the lysis of erythrocytes (24). To assess the effect of osmotic protectants on recPfHly III-induced hemolysis, we estimated hemolytic activity in the presence of glucose and PEG solutes (final concentration, 30 mM).…”

Characterization of Burkholderia pseudomallei protein BPSL1375 validates the Putative hemolytic activity of the COG3176 N-Acyltransferase family

“…These results suggest that BPSL1375 employs a multi-hit hemolytic mechanism that is similar to the hemolysins of other pathogenic bacteria such as B. cereus [ 35 ], Gardenella vaginalis [ 36 ], Streptococcus suis and Synechoctus sp. [ 37 ]. This mechanism is explained by the ability of a single toxin to bind only to a limited quantity of cells to induce hemolysis and is inhibited in the presence of a high ratio of erythrocytes to toxin molecule [ 38 ].…”

“…This mechanism has also been observed in Synechocystic sp. hemolysin, a cyanobacterial toxin [ 37 ].…”