Open AccessSpecificity of DNA-basic polypeptide interactions. 11. Influence of aromatic amino acid residues investigated with agarose bound lysine copolypeptides
Author(s) -
Klaus Wehling,
HansAdolf Arfmann,
Gerhard Seipke,
Karl Wagner
Publication year - 1977
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/4.3.513
Subject(s) - polylysine , lysine , residue (chemistry) , dna , copolymer , agarose , amino acid , biology , biochemistry , polymer , stereochemistry , chemistry , organic chemistry
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.