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On the band gap in peptide α‐helices
Author(s) -
Herz Thomas,
Otto Peter,
Clark Timothy
Publication year - 2000
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/1097-461x(2000)79:2<120::aid-qua7>3.0.co;2-1
Subject(s) - helix (gastropod) , chemistry , dipole , ionization energy , ionization , electron affinity (data page) , peptide , electron , band gap , crystallography , atomic physics , molecular physics , physics , ion , condensed matter physics , molecule , quantum mechanics , ecology , biochemistry , organic chemistry , snail , biology
The variation in the band gap of a (Gly) 30 α‐helix with position in the peptide sequence has been investigated using AM1 semiempirical molecular orbital (MO) theory within an extensive singles configuration interaction (CI) treatment. The dipole‐charge interaction along the length of the helix results in the highest local electron affinity near the N‐terminus and the lowest local ionization potential near the C‐terminus. The calculations suggest that the band gap, measured as the difference between the local ionization potential and electron affinity, decreases from the C‐terminus to the N‐terminus for the model (Gly) 30 α‐helix in vacuo . © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 120–124, 2000