In silico Characterization of Plant and Microbial Antifreeze Proteins

Abstract

Antifreeze proteins (AFPs) are class of proteins that protect organisms from the damage caused by freezing through their ability to inhibit ice growth and effectively lower the temperature at which water freezes. In this study, a total of 25 antifreeze proteins were selected from four different sources (plant, bacteria and fungus) where they represent distinct physicochemical and structural features. Several Physico-chemical properties such as grand average hydropathy (GRAVY), aliphatic index (AI), extinction coefficient (EC), isolelectric point (pI), and instability index (II) were computed. S-S bridges and secondary structures were analyzed using CYS_REC and SOPMA programs respectively. The three dimensional structure of Antifreeze proteins is predicted by using three homology modelling server Geno3D, Swiss-model and CPHmodels. These models were evaluated with PROCHECK, What If, and ProSA programs. Model visualization and analysis was done with Pymol. These structures will provide a good foundation for functional analysis of experimentally derived crystal structures.

Keywords

• Antifreeze Proteins
• Hydrophobicity
• Homology modelling
• In silico analysis
• Isoelectric point