Studies on Interactions between Immobilized Lysine Residues and Oligomers of Thymidylic and Deoxyadenylic Acids

Abstract

Two groups of crosslinked polyacrylic gels with immobilized lysine and lysine peptides (Lys)~ and ( L y~)~-P r o have been used as models for the chromatographic investigation of lysine-peptide -oligonucleotide interactions. One group carries carboxylic groups in addition to the peptide residues in the gel matrix; the other gel type contains no such carboxylic groups in the gel matrix.Nucleotides of the series (dT)2-5, p(dT)l -4, p(dT)l -4p, (dA)2 -5 , p(dA)1-5 and p(dA)1-4p were chromatographed on these gels under various conditions in an aqueous buffer. On the gels of the first group the nucleotides were retarded only slighly, the positive charges of the &-amino groups being compensated partially or totally by the negatively charged carboxyl groups of the polymer matrix. On the gels of the second group, however, the oligonucleotides underwent specific interactions. These interactions were based primarily upon electrostatic forces between the positively charged E-amino groups of the immobilized peptides and the negatively charged phosphate groups of the oligonucleotides.Our results indicate that, in addition to the electrostatic interaction, the conformation plays a crucial role. We explain the selectivity of the interaction with a conformation-fit mechanism. The origin of this mechanism, which creates specific interactions from unspecific forces, is discussed.The organization of DNA and protein in chromatin is at present largely unknown and there is intense research activity in this area [l]. In order to evaluate and interpret histone-DNA interactions for example, model studies have been pursued using synthetic polypeptides [2-61, synthetic histone fragments [7] or histone [8-131 all complexed with DNA. Analysis of these interactions indicates a preferential binding of polylysine and lysine-rich histone to dA . dT-rich DNA. It was also found that the main characteristics which govern the interaction with DNA are located in the very lysine-rich part of the histone molecules In order to obtain more information about the elements of specificity in histone-DNA interactions, simple model systemes are required which allow one to characterize the individual interactions separately. To investigate the binding specificity between a DNA and a histone region, it ought to be profitable to apply [8,121. Abbreviations. The abbreviations for the nucleotides follow CBN Recommendations, see Eur. J . Biochem. 15,203-208 (1970). Note that (dN), has no terminal phosphates, p(dN), only the 5'-termlnal phosphate, p(dN).p both 3' and 5'-terminal phosphates.oligonucleotide-oligopeptide models. Until now, such analyses have not been performed, because convenient methods for the characterization of oligonucleotideoligopeptide interactions have not been available.Recently two methods have been published which make it possible to investigate the oligonucleotideoligopeptide interactions. One method uses the fieldjump technique [14]. The other, a very simple chromatographic approach [15,16], allows one to determine directly the strength...

Nonenzymatic biotinylation of histone H2A

“…In a study of the interaction between mononucleotides and poly-lysine or poly-arginine peptides, electrostatic attractions were shown to be the initial force governing the interaction which, at a high concentration of the nucleotide, led to positioning and adsorption of the nucleotide base along the polyamino acid chain. 28,29 Underscoring the importance of charge around the target lysine, we showed that a highly basic 12-mer peptide of H2A, residues 3-14, was readily biotinylated at all three Lys residues in the presence of bio-5 0 -AMP, whereas the neutral p-67 peptide, residues 660-679, containing two Lys residues, one the target Lys for in vivo biotinylation, was only trace biotinylated in the absence of enzyme. These results mimic the response of fulllength H2A, which was rapidly biotinylated nonenzymatically on the N-terminal tail, when compared with BCCP which was minimally labeled after an overnight incubation.…”

Synthesis of peptide gels for the investigation of oligopeptide–oligonucleotide interactions

“…The acryloyl peptides obtained according to method (1) are very pure and can be characterized, e.g., with 1Hor W-nmr spectroscopy. By using method (2) and (3) the peptides are obtained in almost quantitative yield and are pure enough for copolymerization.…”

“…This determination is based on measurement of the retardation of dissolved oligonucleotides on immobilized amino acids or oligopeptides. [1][2][3] Now we are interested in the Arg-Glu-Lys sequence in which an acidic amino acid is placed between two basic residues. This sequence, as well as Arg-Glu and Glu-Arg sequences, are found in proteins such as the lac and A repressor4p5 and also in several ribosomal proteins.…”