alpha helix Article 4 Protein Conformation, alpha-Helical 4 beta sheet 4 chemistry 4 Protein Conformation, beta-Strand 3 controlled study 3 metabolism 3 protein binding 3 protein domain 3 unclassified drug 3 Binding Sites 2 Escherichia coli 2 Humans 2 Models, Molecular 2 Protein Binding 2 Protein Interaction Domains and Motifs 2 amino terminal sequence 2 binding site 2 gene expression 2 genetics 2 human 2 molecular model 2 nonhuman 2 procedures 2 protein analysis 2 protein conformation 2 protein secondary structure 2 thermodynamics 2 ACE2 protein, human 1