Dynamics and binding mode of Hoechst 33258 to d(GTGGAATTCCAC) sub 2 in the 1:1 solution complex as determined by two-dimensional sup 1 H NMR

Journal Article · Tue Dec 03 04:00:00 EST 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00112a004· OSTI ID:5557845

Fede, A ^[1]; Labhardt, A; Bannwarth, W; Leupin, W ^[2]

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1. F. Hoffmann-La Roche Ltd., Basel (Switzerland) ETH-Hoenggerberg, Zuerich (Switzerland)
2. F. Hoffmann-La Roche, Ltd., Basel (Switzerland)

The authors have investigated the interaction of the bisbenzimidazole derivative Hoechst 33258 with the self-complementary dodecadeoxynulceotide duplex d(GTGGAATTCCAC){sub 2} using one-dimensional (1D) and two-dimensional (2D) proton nuclear magnetic resonance ({sup 1}H NMR) spectroscopy. To monitor the extent of complex formation, they used the imino proton region of the 1D {sup 1}H NMR spectra acquired in H{sub 2}O solution. These spectra show that the DNA duplex loses its inherent C{sub 2v} symmetry upon addition of the drug, indicating that the two molecules form a kinetically stable complex on the NMR time scale (the lifetime of the complex has been measured to be around 450 ms). They obtained sequence-specific assignments for all protons of the ligand and most protons of each separate strand of the oligonucleotide duplex using a variety of homonuclear 2D {sup 1}H NMR experiments. The aromatic protons of the DNA strands, which are symmetrically related in the free duplex, exhibit exchange cross peaks in the complex. Twenty-five intermolecular NOEs were identified, all involving adenine 2 and sugar 1{prime} protons of the DNA and protons in all four residues of the ligand, indicating that Hoeschst 33258 is located in the minor groove at the AATT site. Using molecular mechanics, they have generated a unique model of the complex using distance constraints derived from the intermolecular NOEs. They present, however, evidence that the piperazine group may adopt at least two locally different conformations when the drug is bound to this dodecanucleotide.

• OSTI ID: 5557845
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 30:48; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AZINES
AZOLES
BARYONS
CHEMICAL REACTIONS
CROSS-LINKING
DNA
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
MAGNETIC RESONANCE
MATHEMATICAL MODELS
MOLECULAR MODELS
NUCLEAR MAGNETIC RESONANCE
NUCLEIC ACIDS
NUCLEONS
OLIGONUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OVERHAUSER EFFECT
PIPERAZINES
POLYMERIZATION
PROTONS
PYRAZINES
RESONANCE