The sunflower jacalin Helja: biological and structural insights of its antifungal activity against Candida albicans.

This article focuses on the antifungal activity of Helja, a mannose-binding lectin isolated from sunflower seeds (Helianthus annuus), against Candida albicans, particularly examining its interaction with cell wall mannans. The study demonstrates that Helja exhibits stronger antifungal effects on a C. albicans mnn4Δ null mutant strain deficient in phosphomannan, correlating with increased binding affinity to the mutant’s altered cell wall mannans as shown by solid-phase assays and isothermal titration calorimetry. Unlike in wild-type cells where Helja localizes to the cell wall, in the mutant strain Helja penetrates intracellularly via an endocytosis-independent mechanism, leading to plasma membrane permeabilization and nuclear disintegration. These findings highlight the significance of phosphomannan in modulating lectin binding and antifungal efficacy, suggesting plant lectins like Helja as promising candidates for developing novel antifungal therapies targeting fungal cell wall components.