pH-Dependent Expression, Stability, and Activity of Malassezia restricta MrLip5 Lipase

Abstract

Background: The lipophilic yeasts Malassezia spp. are normally resident on the surface of the human body, and often associated with various skin diseases. Of the 18 known Malassezia spp., Malassezia restricta is the most predominantly identified Malassezia sp. found on the human skin. Malassezia possesses a large number of genes encoding lipases to degrade human sebum triglycerides into fatty acids, which are required not only for their growth, but also trigger skin diseases. Previously, we have shown that MrLIP5 (MRET_0930), one of the 12 lipase genes in the genome of M. restricta, and is the most frequently expressed lipase gene in the scalp of patients with dandruff. Objective: In this study, we aimed to analyze the activity, stability, and expression of MrLip5, with particular focus on pH. Methods: We heterologously expressed MrLip5 in Escherichia coli, and purified and analyzed its activity and expression under different pH conditions. Results: We found that MrLip5 was most active and stable and highly expressed under alkaline conditions, which is similar to that of the diseased skin surface. Conclusion: Our results suggest that the activity and expression of MrLip5 are pH-dependent, and that this lipase may play an essential role at the M. restricta-host interface during disease progression.