Effect of the valine-threonine constraint on the dynamics of the proline helix — A molecular dynamics study

S. Shobana1, Gautham Nadig1, Saraswathi Vishveshwara1
1Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India

Tóm tắt

Proline residues in helices play an important role in the structure of proteins. The proline residue introduces a kink in the helix which varies from about 5° to 50°. The presence of other residues such as threonine or valine near the proline region can influence the flexibility exhibited by the kinked helix, which can have an important biological role. In the present paper, the constraint introduced by threonine and valine on a proline helix is investigated by molecular dynamics studies. The systems considered are (1) a poly-alanine helix with threonine-proline residues (TP) and (2) a poly-alanine helix with valine-threonineproline residues (VTP), in the middle. Molecular dynamics simulations are carried out on these two systems for500 ps. The results are analyzed in terms of structural transitions, bend-related parameters and sidechain orientations.

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Tài liệu tham khảo

Anfinsen C B and Scheraga H A 1975Adv. Protein Chem. 29 205 Barlow D J and Thornton J M 1988J. Mol. Biol. 201 601 Benedetti E 1977Peptides-Proc. Am. Peptide Symp. (ed.) M Goodman & J Meienhofer (New York: John Wiley & Sons) Bhat T N, Sasisekharan V and Vijayan M 1979Int. J. Peptide Protein Res. 13 170 Brandi C J and Deber C M 1986Proc. Natl. Acad. Sci. USA 83 917 Chou P Y and Fasman G D 1974Biochemistry 13 211 Chou P Y and Fasman G D 1977J. Mol. Biol. 115 135 Lapeyre B, Bourbon H and Amalric F 1987Proc. Natl. Acad. Sci. USA 84 1472 MacArthur M W and Thornton J M 1991J. Mol. Biol. 218 397 Milner-White E J, Bell L H and Maccallum P H 1992J. Mol. Biol. 228 725 Richardson J S and Richardson D C 1988Science 240 1648 Robson B and Suzuki E 1976J. Mol. Biol. 107 327 Rose G D, Gierasch L M and Smith J A 1985Adv. Protein Chem. 37 1 Sankararamakrishnan R and Vishveshwara S 1990Biopolymers 30 287 Sankararamakrishnan R and Vishveshwara S 1991Biophys. Chem. 40 97 Sankararamakrishnan R and Vishveshwara S 1992Int. J. Peptide Protein Res. 39 356 Sankararamakrishnan R and Vishveshwara S 1993Proteins — Struct. Function Genet. 15 26 Shobana S and Vishveshwara S 1993Biophys. Chem. 46 77 Suzuki M 1991Nucleic Acids Mol. Biol. (eds) F Eckstein and D M J Lilley (Berlin, Heidelberg: Springer-Verlag) 5 126 Weiner P and Kollman P A 1981J. Comput. Chem. 2 287 Weiner S J, Kollman P A, Case D A, Singh U C, Ghio C, Alagona G, Profeta Jr S and Weiner P 1984J. Am. Chem. Soc. 106 765 Weiner S J, Kollman P A, Nguyen D J and Case D A 1986aJ. Comput. Chem. 7 230 Weiner P K, Singh U C, Kollman P A, Caldwell J and Case D A 1986b A molecular mechanics and dynamics program — AMBER, (University of California, San Francisco) Woolfson D N and Williams D H 1990FEBS Lett. 277 185