Investigating the Lyoprotective Properties of a Plant Antifreeze Protein

Lyophilization, or freeze-drying, is an important preservation method for protein-based products, such as protein pharmaceuticals. However, the process introduces both freezing and drying stresses that can harm proteins. Here, I have studied if AnAFP, a dehydrin-like antifreeze protein isolated from the broadleaf desert shrub Ammopiptanthus nanus, can protect the cold-sensitive enzyme lactate dehydrogenase (LDH) from lyophilization-induced damage. Given AnAFP’s homology to dehydrins and antifreeze proteins, I hypothesized that it can protect other proteins against both freezing and dehydration damages. LDH, known to be sensitive to both types of damage, was used as a model enzyme. It was found that AnAFP protected LDH from lyophilization damage with similar or better efficacy than 10% w/v sucrose and superior to that of another known antifreeze protein.