Theoretical investigation of β-turn structures of serine-alanine protected dipeptide using quantum calculations
Subject Areas :
1 - IAU
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Abstract :
In this research the β-turn structures of L form of serine-alanine protected dipeptide on Ramachandran map were investigated using quantum calculations at the B3LYP/6-311+G(d,p) and M06-2X/6-311+G(d,p) levels of theory in gas phase. Amongst of 243 plossible conformers of N-For-ser-ala-NH2 protected dipeptide, 26 of the found conformers having β-turn structures. The quantum theory of atoms in molecules were carried out to characterize the nature of the intramolecular hydrogen bonding in β-turn structures. The obtained results reveal that the conformer of type V because of including of three HBs is the most stable one between all β-turn structures. However, the most unstable ( ) β-turn conformer of type I bears two and one HBs at the B3LYP and M06-2X levels of theory, respectively.
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