Repozytorium publikacji - Politechnika Gdańska

The main scientific purpose of our studies was to verify the hypothesis that homoaconitase (HA) from Candida albicans, an enzyme catalyzing a second step of the α-aminoadipate pathway (AAP) of L-Lys biosynthesis may become a new target for antifungal chemotherapy. Previous studies indicated that the A. fumigatus mutant lacking the functional lysF gene, encoding HA, exhibited attenuated virulence in a low-dose mouse infection model of invasive aspergillosis [1]. In the present communication we report results on the identification of the C. albicans gene encoding HA, its targeted disruption and phenotypic characterization of the obtained mutant.A BLAST search of the Candida Genome Database with S. cerevisiae LYS4 sequence, known to encode HA, revealed ORFs 19.3846 and 19.11327. Both alleles of the putative LYS4 gene were sequentially disrupted in C. albicans BWP17 cells using the PCR-based methodology. The null lys4Δ mutant strain was cultivated in YNB minimal medium complemented with L-Lys or other additives. The germination ability of mutant cells was tested in the YPG medium containing 10% fetal calf serum and the defined Lee's amino acid medium.The null lys4Δ mutant exhibited lysine auxotrophy in minimal media that could be fully rescued by the addition of 0.3-0.4 mM L-Lys. Presence of D-Lys and pipecolic acid did not trigger lys4Δ growth but the mutant cells were also able to grow in the presence of alpha-AA, an intermediate of the AAP. The C. albicans mutants lacking HA activity demonstrated strongly reduced, although not completely eliminated, germination ability.

Autorzy

• dr hab. inż. Iwona Gabriel link otwiera się w nowej karcie ,
• Krzysztof Kur,
• Aleksandra Mazur,
• Bernhard Hube,
• prof. dr hab. inż. Sławomir Milewski link otwiera się w nowej karcie