Nonnatural amino acid ligands in heme protein design.
The de novo design, synthesis, and characterization of a four-alpha-helix bundle scaffold containing heme ligated by 4-beta-(pyridyl)-l-alanine (Pal) is presented. The protein scaffold is highly helical, stable, and conformationally specific in the apo-state. Incorporation of heme using the designed bis-Pal axial ligation is shown using UV-visible and EPR spectroscopies. The observed heme midpoint reduction potential, +58 mV versus SHE, is 287 mV (6.8 kcal/mol) higher than the analogous bis-histidine-ligated heme protein.
Privett
Heidi K
HK
Department of Chemistry, Columbia University, New York, New York 10027, USA.
Reedy
Charles J
CJ
Kennedy
Michelle L
ML
Gibney
Brian R
BR
D000409:Alanine / Q000737:chemistry*; D000595:Amino Acid Sequence; D004563:Electrochemistry; D006420:Hemeproteins / Q000138:chemical synthesis / Q000737:chemistry*; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D011725:Pyridines / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
C115669:4-pyridyl-alanine; D006420:Hemeproteins; D011725:Pyridines; D000409:Alanine