Molecular basis for sequence-specific DNA alkylation by CC-1065

Laurence Hurley, Chong Soon Lee, J. Patrick McGovren, Martha A. Warpehoski, Mark A. Mitchell, Robert C. Kelly, Paul A. Aristoff

Research output: Contribution to journalArticle

170 Citations (Scopus)

Abstract

CC-1065 is a potent antitumor antibiotic that binds covalently to N3 of adenine in the minor groove of DNA. The CC-1065 molecule is made up of three repeating pyrroloindole subunits, one of which (the left-hand one or A subunit) contains a reactive cyclopropyl function. The drug reacts with adenines in DNA in a highly sequence-specific manner, overlapping four base pairs to the 5′-side of the covalently modified base. Concomitant with CC-1065 covalent binding to DNA is an asymmetric effect on local DNA structure which extends more than one helix turn to the 5′-side of the covalent binding site. The DNA alkylation, sequence specificity, and biological potency of CC-1065 and a select group of trimeric synthetic analogues were evaluated. The results suggest that (a) noncovalent interactions between this series of compounds and DNA do not lead to the formation of complexes stable enough to be detected by footprinting methods, (b) sequence specificity and alkylation intensity can be modulated by the substituents on the nonreactive middle and right-hand segments, and (c) biological potency correlates well with ability to alkylate DNA. In addition, the extent and the sequence specificity of covalent adduct formation between linear DNA fragments and three analogues comprised of the CC-1065 alkylating subunit linked to zero (analogue A), one (analogue AB), or two (analogue ABC) nonreactive indole subunits were compared. The results suggest that specificity of covalent binding of this analogue series is controlled not by the noncovalent interactions of the B and C subunits with the minor groove but by sequence-dependent reactivity of adenines with the alkylating (A) subunit. However, the B and C subunits markedly increase the apparent rate constant of the reaction with "susceptible" adenines, suggesting that these moieties facilitate noncovalent interactions preceding covalent bond formation. Covalent binding of the analogue consisting only of the alkylating subunit of CC-1065 (analogue A) was associated with the same large asymmetric effect on DNA structure as the entire CC-1065 molecule. This altered local DNA structure could be a consequence of adduct formation. Alternatively, it may be indirect evidence of a particular DNA conformation which existed prior to covalent bond formation and which was "trapped" by the drug. It is proposed that certain adenine-containing sequences have an increased propensity to undergo such a local conformational change and that this is the molecular basis for sequence specificity of these DNA-reactive compounds. These results provide strong experimental evidence for the importance of sequence-dependent site reactivity, rather than noncovalent minor groove interactions, in determining the alkylation specificity of some DNA-reactive molecules.

Original languageEnglish (US)
Pages (from-to)3886-3892
Number of pages7
JournalBiochemistry
Volume27
Issue number10
StatePublished - 1988
Externally publishedYes

Fingerprint

CC 1065
Alkylation
DNA
Adenine
Covalent bonds
Hand
Molecules
Nucleic Acid Conformation

ASJC Scopus subject areas

  • Biochemistry

Cite this

Hurley, L., Lee, C. S., McGovren, J. P., Warpehoski, M. A., Mitchell, M. A., Kelly, R. C., & Aristoff, P. A. (1988). Molecular basis for sequence-specific DNA alkylation by CC-1065. Biochemistry, 27(10), 3886-3892.

Molecular basis for sequence-specific DNA alkylation by CC-1065. / Hurley, Laurence; Lee, Chong Soon; McGovren, J. Patrick; Warpehoski, Martha A.; Mitchell, Mark A.; Kelly, Robert C.; Aristoff, Paul A.

In: Biochemistry, Vol. 27, No. 10, 1988, p. 3886-3892.

Research output: Contribution to journalArticle

Hurley, L, Lee, CS, McGovren, JP, Warpehoski, MA, Mitchell, MA, Kelly, RC & Aristoff, PA 1988, 'Molecular basis for sequence-specific DNA alkylation by CC-1065', Biochemistry, vol. 27, no. 10, pp. 3886-3892.
Hurley L, Lee CS, McGovren JP, Warpehoski MA, Mitchell MA, Kelly RC et al. Molecular basis for sequence-specific DNA alkylation by CC-1065. Biochemistry. 1988;27(10):3886-3892.
Hurley, Laurence ; Lee, Chong Soon ; McGovren, J. Patrick ; Warpehoski, Martha A. ; Mitchell, Mark A. ; Kelly, Robert C. ; Aristoff, Paul A. / Molecular basis for sequence-specific DNA alkylation by CC-1065. In: Biochemistry. 1988 ; Vol. 27, No. 10. pp. 3886-3892.
@article{2044b4f372b64acc9c8c306e6163b2b5,
title = "Molecular basis for sequence-specific DNA alkylation by CC-1065",
abstract = "CC-1065 is a potent antitumor antibiotic that binds covalently to N3 of adenine in the minor groove of DNA. The CC-1065 molecule is made up of three repeating pyrroloindole subunits, one of which (the left-hand one or A subunit) contains a reactive cyclopropyl function. The drug reacts with adenines in DNA in a highly sequence-specific manner, overlapping four base pairs to the 5′-side of the covalently modified base. Concomitant with CC-1065 covalent binding to DNA is an asymmetric effect on local DNA structure which extends more than one helix turn to the 5′-side of the covalent binding site. The DNA alkylation, sequence specificity, and biological potency of CC-1065 and a select group of trimeric synthetic analogues were evaluated. The results suggest that (a) noncovalent interactions between this series of compounds and DNA do not lead to the formation of complexes stable enough to be detected by footprinting methods, (b) sequence specificity and alkylation intensity can be modulated by the substituents on the nonreactive middle and right-hand segments, and (c) biological potency correlates well with ability to alkylate DNA. In addition, the extent and the sequence specificity of covalent adduct formation between linear DNA fragments and three analogues comprised of the CC-1065 alkylating subunit linked to zero (analogue A), one (analogue AB), or two (analogue ABC) nonreactive indole subunits were compared. The results suggest that specificity of covalent binding of this analogue series is controlled not by the noncovalent interactions of the B and C subunits with the minor groove but by sequence-dependent reactivity of adenines with the alkylating (A) subunit. However, the B and C subunits markedly increase the apparent rate constant of the reaction with {"}susceptible{"} adenines, suggesting that these moieties facilitate noncovalent interactions preceding covalent bond formation. Covalent binding of the analogue consisting only of the alkylating subunit of CC-1065 (analogue A) was associated with the same large asymmetric effect on DNA structure as the entire CC-1065 molecule. This altered local DNA structure could be a consequence of adduct formation. Alternatively, it may be indirect evidence of a particular DNA conformation which existed prior to covalent bond formation and which was {"}trapped{"} by the drug. It is proposed that certain adenine-containing sequences have an increased propensity to undergo such a local conformational change and that this is the molecular basis for sequence specificity of these DNA-reactive compounds. These results provide strong experimental evidence for the importance of sequence-dependent site reactivity, rather than noncovalent minor groove interactions, in determining the alkylation specificity of some DNA-reactive molecules.",
author = "Laurence Hurley and Lee, {Chong Soon} and McGovren, {J. Patrick} and Warpehoski, {Martha A.} and Mitchell, {Mark A.} and Kelly, {Robert C.} and Aristoff, {Paul A.}",
year = "1988",
language = "English (US)",
volume = "27",
pages = "3886--3892",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "10",

}

TY - JOUR

T1 - Molecular basis for sequence-specific DNA alkylation by CC-1065

AU - Hurley, Laurence

AU - Lee, Chong Soon

AU - McGovren, J. Patrick

AU - Warpehoski, Martha A.

AU - Mitchell, Mark A.

AU - Kelly, Robert C.

AU - Aristoff, Paul A.

PY - 1988

Y1 - 1988

N2 - CC-1065 is a potent antitumor antibiotic that binds covalently to N3 of adenine in the minor groove of DNA. The CC-1065 molecule is made up of three repeating pyrroloindole subunits, one of which (the left-hand one or A subunit) contains a reactive cyclopropyl function. The drug reacts with adenines in DNA in a highly sequence-specific manner, overlapping four base pairs to the 5′-side of the covalently modified base. Concomitant with CC-1065 covalent binding to DNA is an asymmetric effect on local DNA structure which extends more than one helix turn to the 5′-side of the covalent binding site. The DNA alkylation, sequence specificity, and biological potency of CC-1065 and a select group of trimeric synthetic analogues were evaluated. The results suggest that (a) noncovalent interactions between this series of compounds and DNA do not lead to the formation of complexes stable enough to be detected by footprinting methods, (b) sequence specificity and alkylation intensity can be modulated by the substituents on the nonreactive middle and right-hand segments, and (c) biological potency correlates well with ability to alkylate DNA. In addition, the extent and the sequence specificity of covalent adduct formation between linear DNA fragments and three analogues comprised of the CC-1065 alkylating subunit linked to zero (analogue A), one (analogue AB), or two (analogue ABC) nonreactive indole subunits were compared. The results suggest that specificity of covalent binding of this analogue series is controlled not by the noncovalent interactions of the B and C subunits with the minor groove but by sequence-dependent reactivity of adenines with the alkylating (A) subunit. However, the B and C subunits markedly increase the apparent rate constant of the reaction with "susceptible" adenines, suggesting that these moieties facilitate noncovalent interactions preceding covalent bond formation. Covalent binding of the analogue consisting only of the alkylating subunit of CC-1065 (analogue A) was associated with the same large asymmetric effect on DNA structure as the entire CC-1065 molecule. This altered local DNA structure could be a consequence of adduct formation. Alternatively, it may be indirect evidence of a particular DNA conformation which existed prior to covalent bond formation and which was "trapped" by the drug. It is proposed that certain adenine-containing sequences have an increased propensity to undergo such a local conformational change and that this is the molecular basis for sequence specificity of these DNA-reactive compounds. These results provide strong experimental evidence for the importance of sequence-dependent site reactivity, rather than noncovalent minor groove interactions, in determining the alkylation specificity of some DNA-reactive molecules.

AB - CC-1065 is a potent antitumor antibiotic that binds covalently to N3 of adenine in the minor groove of DNA. The CC-1065 molecule is made up of three repeating pyrroloindole subunits, one of which (the left-hand one or A subunit) contains a reactive cyclopropyl function. The drug reacts with adenines in DNA in a highly sequence-specific manner, overlapping four base pairs to the 5′-side of the covalently modified base. Concomitant with CC-1065 covalent binding to DNA is an asymmetric effect on local DNA structure which extends more than one helix turn to the 5′-side of the covalent binding site. The DNA alkylation, sequence specificity, and biological potency of CC-1065 and a select group of trimeric synthetic analogues were evaluated. The results suggest that (a) noncovalent interactions between this series of compounds and DNA do not lead to the formation of complexes stable enough to be detected by footprinting methods, (b) sequence specificity and alkylation intensity can be modulated by the substituents on the nonreactive middle and right-hand segments, and (c) biological potency correlates well with ability to alkylate DNA. In addition, the extent and the sequence specificity of covalent adduct formation between linear DNA fragments and three analogues comprised of the CC-1065 alkylating subunit linked to zero (analogue A), one (analogue AB), or two (analogue ABC) nonreactive indole subunits were compared. The results suggest that specificity of covalent binding of this analogue series is controlled not by the noncovalent interactions of the B and C subunits with the minor groove but by sequence-dependent reactivity of adenines with the alkylating (A) subunit. However, the B and C subunits markedly increase the apparent rate constant of the reaction with "susceptible" adenines, suggesting that these moieties facilitate noncovalent interactions preceding covalent bond formation. Covalent binding of the analogue consisting only of the alkylating subunit of CC-1065 (analogue A) was associated with the same large asymmetric effect on DNA structure as the entire CC-1065 molecule. This altered local DNA structure could be a consequence of adduct formation. Alternatively, it may be indirect evidence of a particular DNA conformation which existed prior to covalent bond formation and which was "trapped" by the drug. It is proposed that certain adenine-containing sequences have an increased propensity to undergo such a local conformational change and that this is the molecular basis for sequence specificity of these DNA-reactive compounds. These results provide strong experimental evidence for the importance of sequence-dependent site reactivity, rather than noncovalent minor groove interactions, in determining the alkylation specificity of some DNA-reactive molecules.

UR - http://www.scopus.com/inward/record.url?scp=0024290406&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0024290406&partnerID=8YFLogxK

M3 - Article

VL - 27

SP - 3886

EP - 3892

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 10

ER -