Antifreeze proteins (AFP) have been isolated from multiple organisms that live in Polar regions. AFPs have the ability to bind with high affinity to the surface of ice crystals, modifying ice growth kinetics, morphology and freezing point. The aim of this project is the synthesis of switchable helical AFPs with cyclically attached photoactive organic molecule. As the protein’s ice binding activity depends on the intactness of its fold, activity will be switched by length variation between the cis-/trans-azobenzene isomers and concomitant protein unfolding. The possibility of switching function is of interest in all applications, where a temporal or spatial control of protein activity is needed.