title: Structural insights into the stability perturbations induced by N-terminal variation in human and goat α-lactalbumin.
abstract: Addition of an extra methionine at the N-terminus by recombinant expression of α-lactalbumin in Escherichia coli significantly destabilizes the protein, and this destabilization has hampered mutational analyses such as the mutational phi-value analysis of the protein. Deletion of residue 1 from the recombinant form recovers the stability in human and goat α-lactalbumin. Here, we thus determined the crystal structures of the residue 1-deletion variants of recombinant human and goat α-lactalbumin, and compared the structures with those of the authentic and recombinant forms. The results demonstrate the importance of the N-terminal backbone structure and hydrogen-bonding pattern for the stability of α-lactalbumin.
authors.affiliation: Okazaki Institute for Integrative Bioscience and Institute for Molecular Science, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan. makabe@yz.yamagata-u.ac.jp
authors.forename: Koki
authors.initials: K
authors.lastname: Makabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Kuwajima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018360:Crystallography, X-Ray; D006041:Goats; D006801:Humans; D006860:Hydrogen Bonding; D007768:Lactalbumin / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D016297:Mutagenesis, Site-Directed; D055550:Protein Stability; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D058767:Protein Unfolding; D017384:Sequence Deletion; D013816:Thermodynamics
chemical_list: D007768:Lactalbumin