Conformational Dynamics of Human alpha-Fetoprotein-Derived Heptapeptide LDSYQCT Analogs

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N. T. Moldogazieva^1*, A. A. Terentiev¹, A. N. Kazimirsky¹, M. Yu. Antonov², and K. V. Shaitan²

¹Russian State Medical University, ul. Ostrovityanova 1, 117997 Moscow, Russia; fax: (495) 434-0588; E-mail: nmoldogazieva@mail.ru; aaterent@mtu-net.ru

²Department of Bioengineering, Lomonosov Moscow State University, 119992 Moscow, Russia; fax: (495) 939-2374; E-mail: shaitan@moldyn.org

^* To whom correspondence should be addressed.

Received August 11, 2006; Revision received January 18, 2007

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Conformational dynamics of a biologically active fragment of alpha-fetoprotein, the heptapeptide LDSYQCT, and its analogs obtained by site-directed substitutions of amino acid residues were studied. The conformational dynamics of the peptide were conservative under the substitutions Y17F, Y17S, and D15E. Substitutions C19A and S16V resulted only in local changes in the dynamic behavior of the peptide. Chemical modification of cysteine (C19) or dimerization of the peptide by producing a disulfide bond between cysteine residues of two parallel peptide chains, as well as the substitutions C19G, C19S, Q18E, and D15N changed a set of possible conformations and dynamic behavior of all amino acid residues. The most significant changes were caused by substitution of uncharged amino acid residues by charged ones, and vice versa.

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KEY WORDS: molecular dynamics, alpha-fetoprotein, site-directed substitutions, peptides

DOI: 10.1134/S0006297907050094

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