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A temperature‐jump kinetic study of the binding of proflavine to poly I·poly C
Author(s) -
Steenbergen Charles,
Mohr Scott C.
Publication year - 1973
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.1973.360120408
Subject(s) - proflavine , chemistry , polynucleotide , kinetics , ionic strength , isomerization , temperature jump , dna , kinetic energy , crystallography , biochemistry , aqueous solution , catalysis , physics , quantum mechanics
The kinetics of interaction between proflavine and poly I.poly C at 25°C, neutral pH, and moderate ionic strength have been studied by relaxation methods. The qualitative features of this system resemble those previously reported by Crothers and co‐workers for proflavine–DNA and proflavine–poly A·poly U interactions–two relaxations are observed coresponding to a fast bimolecular step followed by a slower isomerization. These results can best be accommodated by a two‐step mechanism leading from the free dye through an “outside‐bound” complex to the intercalated complex. Quantitative comparison of the various rate constants for proflavine binding to different double‐helical polynucleotides shows that the rates are slower for both ribohomopolymer pairs than for DNA. The rates for poly I·poly C are approximately three times faster than these for poly A·poly U.