Binding of Hoechst 33258 and 4 prime ,6-diamidino-2-phenylindole to self-complementary decadeoxynucleotides with modified exocyclic base substituents

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00215a027· OSTI ID:5476416

Loontiens, F G; Diekmann, S; Clegg, R M ^[1]; McLaughlin, L W ^[2]

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1. Max Planck Institut fur biophysikalische Chemie, Gottingen (Germany)
2. Boston College, Chestnut Hill, MA (USA)

Fluorescence titrations have been carried out to determine the association constants (K{sub a}) for binding of the dyes Hoechst 33258 and DAPI to the self-complementary decamer d(CTGAATTCAG) and nine duplex derivatives with exocyclic substituent changes in the six central base pairs. Many K{sub a} values are in the range (2-5) {times} 10{sup 8} (duplex M){sup {minus}1} at 5.5 {degree}C. Replacement of the leftmost adenine by 2-aminopurine in the sequence decreases K{sub a} for Hoechst 33258 by a factor of 170. When the centermost adenine is replaced by 2-aminopurine, K{sub a} for Hoechst 33258 and DAPI is too small to be evaluated. When the centermost adenine is replaced by purine, K{sub a} for both dyes increases, but this very stable duplex-Hoechst 33258 complex is nonfluorescent. The measured affinities are compared to expectations derived from X-ray studies with dodecamer-dye complexes having an identical central binding sequence.

• OSTI ID: 5476416
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 30:1; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AROMATICS
AZAARENES
AZOLES
BIOCHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COHERENT SCATTERING
CROSS-LINKING
DIFFRACTION
DYES
FLUORESCENCE
HETEROCYCLIC COMPOUNDS
INDOLES
KINETICS
LUMINESCENCE
NUCLEIC ACIDS
OLIGONUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
POLYMERIZATION
PYRROLES
REACTION KINETICS
SCATTERING
TITRATION
X-RAY DIFFRACTION