Effect of freezing stress on the proteome expression of Antarctic green microalga

Abstract

The effects of freezing stress on the protein expression profile and enzyme activity change in Antarctic green microalga were examined in this investigation. Antarctic green microalga was cultured at 4 degrees C for optimal growth, and the temperature was reduced near to 0 degrees C in order to apply freezing stress. The resultant differentially expressed proteins induced by freezing stress were analyzed by mass spectrometry following two-dimensional gel electrophoresis (2-DE). In total, about 320 protein spots were detected on the 2-DE gel, and 17 proteins showed a greater than two-fold change in abundance; of these, 5 proteins were up-regulated, and 12 proteins were down-regulated. Moreover, total enzyme activities and isozyme patterns of several antioxidant enzymes, named catalase, superoxide dismutase and aldehyde dehydrogenase were changed upon applying freezing stress.