title: Role of medium- and long-range interactions to the stability of the mutants of T4 lysozyme.
abstract: Inter-residue interactions play an important role to the folding and stability of protein molecules. In this work, we analyze the role of medium- and long-range interactions to the stability of T4 lysozyme mutants. We found that, in buried mutations, the increase in long-range contacts upon mutations destabilizes the protein, whereas, in surface mutations, the increase in long-range contacts increases the stability, indicating the importance of surrounding polar residues to the stability of surface mutations. Further, the increase in medium-range contacts decreases the stability of buried and surface mutations and a direct relationship is observed between the increase of medium-range contacts and increase in stability for partially buried/exposed mutations. Moreover, the relationship between amino acid properties and stability of T4 lysozyme mutants at positions Ile3, Phe53, and Leu99 showed that the effect of medium- and long-range contacts is less for buried mutations and the inter-residue contacts have significant correlation with the stability of partially buried mutations.
authors.affiliation: RIKEN Tsukuba Institute, The Institute of Physical and Chemical Research, Ibaraki, Japan. gromiha@rtc.riken.go.jp
authors.forename: M M
authors.initials: MM
authors.lastname: Gromiha
authors.forename: A M
authors.initials: AM
authors.lastname: Thangakani
mesh_terms: D017122:Bacteriophage T4 / Q000201:enzymology* / Q000235:genetics; D001665:Binding Sites; D030562:Databases, Protein; D004795:Enzyme Stability; D008958:Models, Molecular; D009113:Muramidase / Q000737:chemistry* / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D009113:Muramidase