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Table 3 The interaction energies and bond lengths of four amino acid Hp-π interaction pairs (Ser–Phe, Lys–Phe, Tyr–Phe, and His–Phe)

From: Theoretical study on the polar hydrogen-π (Hp-π) interactions between protein side chains

  (Ser–Phe) (Lys–Phe) (Tyr–Phe) (His–Phe)
  CH3OH-C6H6 CH3NH2-C6H6 C6H5OH-C6H6 Imid-C6H6
Position Center Center Center Center
a Energy -19.7648 -8.7661 -21.7831 -25.771
b Bond length 2.410 c3.550, 3.093 2.425 2.315
  1. a Interaction energies are in kJ/mol, calculated using CCSD/6-311 + G(d,p) plus ghost atom H-Bq.
  2. b Bond lengths are in angstrom (Å) from polar hydrogen to the center of benzene ring.
  3. c The Bond length 3.550 Å is from N of Lys to the benzene ring center of Phe, and 3.093 Å is the distance from a polar hydrogen atom of Lys to a carbon atom of Phe.