ИСТИНА

Background The most common fungal infections in humans are candidiases caused by Candida yeast. A major, highly conserved yeast cell wall (CW) protein Bgl2p, which can also be secreted into the growth medium, plays a significant role in candidiasis. It was shown that the injected into a mouse's bloodstream C.albicans with BGL2 deletion possessed decreased infectivity compared to the one without BGL2 deletion (Sarthy et al., 1997). On the other hand, high level of antibodies against Bgl2p is prognostic factor, which defines the risk of mortality (Pitarch et al., 2006). Authors proposed to use Bgl2p from C.albicans for vaccine development. Earlier we demonstrated that Bgl2p from S.cerevisiae CW(Bgl2p homolog from C.albicans) could reveal amyloid properties (Kalebina et al., 2008). At the beginning of our work the process of Bgl2p amyloid formation remained unclear. Objectives The study of Bgl2p fibril forming ability under conditions similar to those of a bloodstream. Primarily we were interested in investigating the influence of two factors on Bgl2p fibrillation: the pH value within a neutral range and the presence of regulatory molecules such as polyphosphates. Methods We investigated Bgl2p from non-pathogenic S.cerevisiae as a model using fluorescence confocal and electron microscopy, fluorescence spectroscopy, bioinformatics analysis. Conclusions Bgl2p fibril formation ability was strongly regulated by pH value (Bezsonov et al., 2013), polyphosphates, divalent cations and buffer components. The results obtained allowed us to conclude what Bgl2p form might exist under bloodstream-like conditions. The described Bgl2p amyloid formation ability is important for further fighting the candidiasis including vaccine development, using Bgl2p from non-pathogenic S.cerevisiae.