Characterization of a haemolytic factor from Candida albicans

Abstract

The culture supernatant of Candida albicans promoted the disruption of human red blood cells (RBCs). The haemolytic activity was detected in a sugarrich fraction (about 200 kDa) from Sephacryl S-100 chromatography. As the haemolytic activity was adsorbed by concanavalin A-Sepharose, the haemolytic factor may be a mannoprotein. The activity was inactivated by periodate oxidation, indicating that the sugar moiety of the mannoprotein played an important role in the haemolysis. The structure of the sugar moiety of the mannoprotein was identified as a cell-wall mannan by 'H-NMR analysis, and purified C. albicans mannan promoted the disruption of RBCs. The binding of mannan to RBCs was demonstrated by flow cytometric analysis and was inhibited by the addition of band 3 protein inhibitor, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS). The haemolysis caused by mannan was inhibited by DIDS, SITS (4-acetamido-4'-isothiocyanatostiIbene-2,2'-disulfonic acid) and bis(sulfosuccinimidy1) suberate, but not by pyridoxal 5-phosphate. These results indicated that a mannoprotein released from C. albicans bound to the band 3 protein on RBCs, thereby promoting their disruption.

Iron acquisition in the cystic fibrosis lung and potential for novel therapeutic strategies

“…In vitro, both Rbt5 and Pga7 extract haem from haemoglobin, and haem can be rapidly transferred between these two CFEM proteins (Kuznets et al, 2014). Candida albicans also produces the haemolytic molecule mannan which facilitates access to haembound iron (Tanaka et al, 1997;Watanabe et al, 1999). Interestingly, Aspergillus fumigatus lacks the ability to use haem as an iron source (Eisendle et al, 2003) and its CFEM domain proteins do not play a role in either haem uptake or virulence (Vaknin et al, 2014).…”

Comparison of the hemolytic activity between C. albicans and non-albicans Candida species

“…This factor most likely corresponds to a mannoprotein bound to the cell surface of the fungus. 5,8 However, the mechanism and molecular basis of hemolysis caused by C. albicans remain unknown. 5 In the oral cavity, extracellular iron is bound mainly to lactoferrin, a protein present in saliva, while intracellular iron is stored as ferritin.…”

Impact of Enzymes and Toxins Potentiality of Four Aspergillus Species to Cause Aspergillosis

“…The extracts collected from the mycelium of the fungus grown for 2-4 days were heat sensitive, hemolytic, and produced necrosis and edema when introduced in experimental animals. It is certain that numerous pathogenic microorganisms grow in the host by using hemin or hemoglobin as a source of iron [53][54][55]. Several fungal hemolysins have been proposed as virulence factors [56,57].…”