Energetics of Ligand Recognition and Self-Association of Bovine beta-Lactoglobulin: Differences between Variants A and B
Por:
Bello, M, Portillo-Tellez, MD, Garcia-Hernandez, E
Publicada:
11 ene 2011
Categoría:
Biochemistry
Resumen:
An understanding of the interplay between structure and energetics is crucial for the optimization of modern protein engineering techniques. In this context, the study of natural isoforms is a subject of major interest, as it provides the scenario for analyzing mutations that have endured during biological evolution. In this study, we performed a comparative analysis of the ligand-recognition and homodimerization energetics of bovine beta-lactoglobulin variants A (beta lgA) and B (beta lgB). These variants differ by only two amino-acid substitutions: 64th (Asp(A) -> Gly(B)), which is fully exposed to the solvent, and 118th (Val(A) -> Ala(B)), immersed in the hydrophobic core of the protein. Calorimetric measurements revealed significant enthalpic and entropic differences between the isoforms in both binding processes. A structural comparison suggests that a variation in the conformation of the loop C-D, induced by mutation Asp/Gly, could be responsible for the differences in ligand-bin
Filiaciones:
Bello, M:
Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04510, DF, Mexico
Portillo-Tellez, MD:
Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04510, DF, Mexico
Garcia-Hernandez, E:
Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04510, DF, Mexico
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