Figure 2

Stability of IPNS produced by H. polymorpha strain IPNS 4.2 cultivated at various temperatures. H. polymorpha IPNS 4.2 cells were cultivated on methanol media to the mid-exponential growth phase (A₆₆₀ of approximately 1.5) at 37°C, 30°C and 25°C (panels A, B, and C, respectively). Subsequently, 0.5% glucose was added to repress the AOX promoter and stop further IPNS synthesis. Aliquots of the cultures were taken at the indicated time intervals after the shift. Western blots were prepared using equal volume fractions loaded per lane. For clarity, in panels B and C protein samples were diluted 10 times prior to loading. The results show that in IPNS 4.2 cells cultivated at 37°C IPNS protein is unstable since little protein is detected 1 h after the shift. In cells cultivated at lower temperatures, IPNS protein remains detectable at all time points.