Figure 5. Effect of tunicamycin (TM) on the NAGase (N-acetyl-β-d-glucosaminidase) activity of P. brasiliensis yeasts.

P. brasiliensis yeasts cultured in YPD medium in the absence or presence of 15 µg/mL TM were disrupted to obtain crude extracts. The time-course profile of NAGase activity, as detected by the degradation of pNP-GlcNAc substrate (A); the effect of TM on the expression of paracoccin, a P. brasiliensis protein with NAGase activity, shown by ELISA using anti-paracoccin IgY and measured at 450 nm (B); and profiles of optimal pH (C) and temperature (D) for the fully glycosylated and underglycosylated NAGases. Maximum activity was standardized as 100% and NAGase activities were measured at 405 nm. Data are representative of 3 independent assays.