Influence of intramolecular interactions on conformational and dynamic properties of analogs of heptapeptide [AFP.sub.14-20]

• Published in: Biochemistry (Moscow) 2011-12, Vol.76 (12), p.1321
• Main Authors: Moldogazieva, N.T, Shaitan, K.V, Antonov, M.Yu, Vinogradova, I.K, Terentiev, A.A
• Format: Article
• Language: English
• Subjects: Amino acids; Analysis; Chemical properties; Glycoproteins; Peptides
• ISSN: 0006-2979
• DOI: 10.1134/S0006297911120054

Conformational and dynamic properties of proteins and peptides play an important role in their functioning. However, mechanisms that underlie this influence have not been fully elucidated. In the present work we computationally constructed analogs of heptapeptide [AFP.sub.14-20] (LDSYQCT)--one of the biologically active sites of human α- fetoprotein (AFP)--to study their conformational and dynamic properties using molecular dynamics simulation. Analogs were obtained by point substitutions of amino acid residues taking into account differences in their physicochemical properties and also on the basis of analysis of amino acid substitutions in the [AFP.sub.14-20] like motifs revealed in different physiologically active proteins. It is shown that changes in conformational mobility of amino acid residues of analogs are due to disruption or arising of intramolecular interactions that, in turn, determine existence of steric restrictions during rotation around covalent bonds of the peptide backbone. Substitution of an amino acid by another one with significant difference in physico- chemical properties may not lead to remarkable changes in conformational and dynamic properties of the peptide if intramolecular interactions remain unchanged. DOI: 10.1134/S0006297911120054 Key words: α-fetoprotein, AFP, analogs of heptapeptide [AFP.sub.14-20], molecular dynamics, intramolecular interactions