title: [Study of the spatial structure of the product of intracomplex alkylation of the octanucleotide pd(TGTTTGGC) by 4-(N-methyl-N-(2-chloroethyl) amino)benzyl-5'-phosphamide derivative of the heptanucleotide pd(CCAAACA) in an aqueous solution by two-dimensional 1H-NMR spectroscopy and constrained molecular mechanics].
abstract: Using one- and two-dimensional 1H NMR spectroscopy (400 MHz), a detailed study of the spatial structure of the covalent adduct, a product of the intracomplex alkylation of octanucleotide pd[TGTTTGGC] by the 4-[N-methyl-N-(2-chloroethyl)amino]benzyl-5'-phosphamide derivative of heptanucleotide pd[CCAAACA] in aqueous solution, was continued. The distances between closely spaced protons of oligonucleotides as well as between protons of the benzylamide fragment and protons of the nearest nucleotide units were determined by measurements of the nuclear Overhauser effect. Analysis of effective correlation times for some pairs of protons of the covalent adduct showed that the values of tau c for the benzylamide fragment and nucleotide units C-1 and C-8, which directly interact with it, coincide and are smaller than those for the internal nucleotide units, suggesting the increased rigidity of the structure in the vicinity of the modification region. Using the method of constrained molecular mechanics, a probable state of the covalent adduct in solution is proposed that is in the best agreement with the experimentally obtained set of interproton distances. Problems connected with calculating the distance between a pair of protons with coincident chemical shifts and any third proton are considered.
authors.forename: L A
authors.initials: LA
authors.lastname: Gorenshteĭn
authors.forename: E V
authors.initials: EV
authors.lastname: Bichenkova
authors.forename: Iu N
authors.initials: IuN
authors.lastname: Vorob'ev
authors.forename: A V
authors.initials: AV
authors.lastname: Lebedev
mesh_terms: D000478:Alkylation; D001483:Base Sequence; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009841:Oligonucleotides / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D012996:Solutions
chemical_list: C095445:4-(N-methyl-N-(2-chloroethyl)amino)benzyl-5'-phosphamide; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D012996:Solutions
vernacular_title: Issledovanie prostranstvennoĭ struktury produkta vnutrikompleksnogo alkilirovaniia oktanukleotida pd(TGTTTGGC) 4-(N-metil-N-(2-khlorétil)amino)benzil-5'-fosfamidnym proizvodnym geptanukleotida pd(CCAAACA) v vodnom rastvore metodom dvumernoĭ 1H-IaMR-spektroskopii i ogranichennoĭ molekuliarnoĭ mekhaniki.