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Helical region of the potential energy surface of α‐aminoisobutyric acid: A theoretical study
Author(s) -
Alemán Carlos,
Perez Juan J.
Publication year - 1993
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/qua.560470307
Subject(s) - ab initio , force field (fiction) , potential energy surface , chemistry , surface (topology) , potential energy , dipeptide , ab initio quantum chemistry methods , quantum , field (mathematics) , molecular physics , computational chemistry , helix (gastropod) , computation , atomic physics , physics , molecule , quantum mechanics , amino acid , geometry , biochemistry , mathematics , organic chemistry , algorithm , computer science , pure mathematics , ecology , snail , biology
The helical region of the potential energy surface of blocked α‐aminoisobutyric acid (Aib) dipeptide has been studied by using ab initio and semiempirical quantum mechanical methods, as well as force‐field‐derived methods. Depending on the method, an α‐helix or a 3 10 ‐helix is found to be the energy minimum. The conformations obtained from computations performed at the ab initio quantum mechanical level, as well as by using the AMBER force field, are in excellent agreement with X‐ray data. Semiempirical results display some important differences with regard to experimental data. On the other hand, the CVFF force field predicts no energy minimum in the helical region of the Aib potential energy surface. © 1993 John Wiley & Sons, Inc.