title: Specificity of DNA basic polypeptide interactions. II+ Influence of aromatic amino acid residues investigated with agarose bound lysine copolypeptides.
abstract: Binding affinities towards DNA and base pair specificities of lysine copolymers, containing different amounts of Phe, Tyr or Trp residues, were estimated using a previously described chromatographic method. Incorporation of few aromatic residues into polylysine causes a decrease in the binding affinity, however, further raising the aromatic residue - lysine ratio results in a continous increase of affinity, which is most pronounced with the Tyr copolymers and not observed with polymers containing neutral aliphatic amino acid residues. AT-specificity increases concomitant with binding affinity in the case of the Tyr copolymers but not with the Phe copolymers. The interaction of DNA with the alternating Phe-Lys polymer is significantly stronger than with the random copolymer of equal residue composition. The molecular and conformational reasons determining specificity are discussed.
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D003016:Clostridium perfringens; D004269:DNA, Bacterial / Q000378:metabolism*; D008239:Lysine; D008837:Micrococcus; D010455:Peptides / Q000378:metabolism*; D010649:Phenylalanine; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D014364:Tryptophan; D014443:Tyrosine
chemical_list: D004269:DNA, Bacterial; D010455:Peptides; D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan; D008239:Lysine