Premium
Extrinsic cotton effects of proflavine bound to polynucleotides
Author(s) -
Blake A.,
Peacocke A. R.
Publication year - 1967
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1967.360050407
Subject(s) - proflavine , chemistry , polynucleotide , nucleic acid , dna , molecule , polyaspartic acid , stereochemistry , crystallography , biochemistry , organic chemistry , raw material
The magnitude of the Cotton effect of proflavine which is bound to RNA or to denatured DNA depends on the ratio of bound proflavine to nucleic acid base. A statistical treatment which explains this behavior has been fitted to the experimental curves and indicates that optical activity arises through interaction between two or more bound proflavine molecules. The corresponding requirement with double helical DNA is for interaction between 3–4 proflavine molecules. Although proflavine binds to denatured DNA at pH 2.8, as shown by the shift of the proflavine spectrum, the strong binding process is absent, and to this is attributed the absence of the Cotton effect at low pH. Studies on the Cotton effects of proflavine bound to poly A and poly U at neutral pH, to poly A at acid pH and to poly (A + U) allow the generalization that a relatively rigid configuration of the binding macromolecule is required for the induction of these extrinsic Cotton effects.