Search Proteins With Potential Thermal Hysteresis In Hepialus Altaicola By Sequence Motif Analysis And Molecular Dynamics Simulation

Antifreeze proteins(AFPs)can inhibit the growth and recrystallization of ice crystals in a non-colligative form,and it is defined as thermal hysteresis(TH).AFPs can defend cell against frozen damage.Hepialus altaicola live in the high altitude and cold Altai Mountains area.Protein sequences of hepialus altaicola are analyzed by using motif finding and molecular dynamics simulation method.Protein sequences with potential thermal hysteresis have been found.The results provide a way for understanding the cold-resistant of hepialus altaicola.The results also give a theoretical reference for experimental work to identify AFPs of hepialus altaicola.There are 1175 AFPs sequences in the UniProt DataBase,including 130 insect AFPs sequences.Based on the analysis of all AFPs sequences in UniProt DataBase,three motifs of insect AFPs sequences are obtained by using MEME motif search software.The proportion of hydrophobic amino acids are most in these insect AFPs motifs.And chemical structure of the R group of each amino acid of three insect AFPs motifs are different.The three insect AFPs motifs have been BLAST aligned with the protein sequences of a hepialus altaicola.Based on the results of BLASTaligned five protein sequences are located.Two protein sequences with top score in the five located sequences and a protein sequence that is randomly selected from protein sequence of hepialus altaicola homologously modeled.These three proteins are calculated using molecular dynamics simulation(MD)method,the effect of three homologously modeled protein sequences on ice-water system for Basal-plane of ice crystal is obtained respectively.Compared with the effects of snow fleas antifreeze protein(SfAFP)and choristioneure fumiferana antifreeze protein(CfAFP),the results show that the first ranked protein sequence has potential thermal hysteresis activity.