Hydrogen Bonding of 1,2-Azaborines in the Binding Cavity of T4 Lysozyme Mutants: Structures and Thermodynamics.
Protein crystallography and calorimetry were used to characterize the binding of 1,2-azaborines to model cavities in T4 lysozyme in direct comparison to their carbonaceous counterparts. In the apolar L99A cavity, affinity for Ab dropped only slightly versus benzene. In the cavity designed to accommodate a single hydrogen bond (L99A/M102Q), Gln102═O···H-N hydrogen bonding for Ab and BEtAb was observed in the crystallographic complexes. The strength of the hydrogen bonding was estimated as 0.94 and 0.64 kcal/mol for Ab and BEtAb, respectively. This work unambiguously demonstrates that 1,2-azaborines can be readily accommodated in classic aryl recognition pockets and establishes one of 1,2-azaborine's distinguishing features from its carbonaceous isostere benzene: its ability to serve as an NH hydrogen bond donor in a biological setting.
Department of Chemistry, Boston College , Chestnut Hill, Massachusetts 02467, United States.
Hyelee
H
Lee
Department of Pharmaceutical Chemistry, University of California, San Francisco , San Francisco, California 94158, United States.
Marcus
M
Fischer
Department of Pharmaceutical Chemistry, University of California, San Francisco , San Francisco, California 94158, United States.
Brian K
BK
Shoichet
Department of Chemistry, Boston College , Chestnut Hill, Massachusetts 02467, United States.
Shih-Yuan
SY
Liu
D001896:Boron Compounds / Q000737:chemistry*; D002151:Calorimetry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism; D013816:Thermodynamics
C556261:1,2-azaborine; D001896:Boron Compounds; D009113:Muramidase