Effect of the purification of antidermatophytic proteins from Nigella sativa on four zoophilic species
The antidermatophytic activities of proteins which are extracted from four plant species (Carum carvi, Cymbopogon citratus, Moringa oleifera, and Nigella sativa) on four zoophilic dermatophytes (Microsporum canis, Microsporum equinum, Trichophyton mentagrophytes, and Trichophyton verrucosum) were evaluated in this study. The crude proteins of N. sativa had the broadest significant spectrum of antidermatophytic activity on the tested dermatophytes as well as the greatest antioxidant activity (95.11%) and the highest protein content (82 mg/ml). 17 amino acids were found in the four tested plant proteins with N. sativa protein having the highest content of amino acid (347.21 μg/ml). N. sativa protein had the greatest effect on the fungal cell permeability of all the tested zoophilic dermatophytes. Purification of N. sativa protein on Sephadex G-100 column showed two peaks of protein (Pr1 and Pr2) as well as increasing antidermatophytic activities. Complete purification of the most active fraction (Pr2) on diethylaminoethyl (DEAE)-Sephadex eluted one single peak with increasing antidermatophytic activity (7.6 cm) against the most sensitive pathogen (M. canis), representing 1.43 fold purification of the crude protein. The molecular weights of the purified N. sativa proteins (Pr1 and Pr2) were 42.7 and 31 kDa, respectively. The highest antidermatophytic activity of Pr2 was observed at a pH of 7 and temperature of 20°C. Na+, K+, Ca2+ and Mg2+ decreased the antidermatophytic activity of the pure protein of N. sativa.
Key words: Dermatophytes, plant, protein, purification.