title: [Interaction of trivaline with single-stranded polyribonucleotides].
abstract: Binding of tripeptide H-Val3-(NH)2-Dns (TVP) to polyribonucleotides was studied by fluorescence methods, circular and flow linear dichroism, equilibrium dialysis and electron microscopy. It was found that TVP binds to poly(U) in monomer, dimer and tetramer forms with binding constants of about 10(3), 40, 18.10(4) M, respectively. The cooperativity parameter for peptide dimer binding is 2000. The peptide forms tetramer complexes with poly(A), poly(C), poly(G) also. The formation of a complex between the peptide tetramer and nucleic acid is accompanied by a significant increase in the fluorescence intensity. The cooperative binding of TVP dimers to poly(U), poly(A), poly(C) is accompanied by a dramatic decrease in the flexibility of polynucleotide chains. However, it has a small effect (if any) on the flexibility of the poly(G) chain. The observed similarity of thermodynamic, optical and hydrodynamic++ properties of TVP complexes with single-stranded and double-stranded nucleic acids may reflect a similarity in the geometries of peptide complexes with nucleic acids. Electron microscopy studies show that peptide binding to poly(U) and dsDNA leads to compactization of the nucleic acids caused by interaction between the peptide tetramers bound to a nucleic acid. At the first stage of the compactization process the well-organized rod-like particles are formed, each consisting of one or more single-stranded polynucleotide fibers. Increasing the peptide concentration stimulates a side-by-side association and folding of the rods with the formation of macromolecular "leech-like" structures with the thickness of 20-50 nm.
authors.forename: S A
authors.initials: SA
authors.lastname: Strel'tsov
authors.forename: Iu P
authors.initials: IuP
authors.lastname: Lysov
authors.forename: T E
authors.initials: TE
authors.lastname: Semenov
authors.forename: Iu Iu
authors.initials: IuIu
authors.lastname: Vengerov
authors.forename: A A
authors.initials: AA
authors.lastname: Khorlin
authors.forename: A N
authors.initials: AN
authors.lastname: Surovaia
authors.forename: G V
authors.initials: GV
authors.lastname: Gurskiĭ
mesh_terms: D002942:Circular Dichroism; D008854:Microscopy, Electron; D009696:Nucleic Acids / Q000378:metabolism; D009842:Oligopeptides / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism; D011131:Polyribonucleotides / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D009696:Nucleic Acids; D009842:Oligopeptides; D010455:Peptides; D011131:Polyribonucleotides; C025780:dansylhydrazide trivaline
vernacular_title: Vzaimodeĭstvie trivalina s odnonitevymi poliribonukleotidami.