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Perturbing the DNA Sequence Selectivity of Metallointercalator−Peptide Conjugates by Single Amino Acid Modification

Hastings, Curtis A. and Barton, Jacqueline K. (1999) Perturbing the DNA Sequence Selectivity of Metallointercalator−Peptide Conjugates by Single Amino Acid Modification. Biochemistry, 38 (31). pp. 10042-10051. ISSN 0006-2960. doi:10.1021/bi982039a. https://resolver.caltech.edu/CaltechAUTHORS:20160407-115523468

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Abstract

Metallointercalator−peptide conjugates that provide small molecular mimics to explore peptide−nucleic acid recognition have been prepared. Specifically, a family of peptide conjugates of [Rh(phi)_2(phen‘)]^(3+) [where phi = 9,10-phenanthrenequinone diimine and phen‘ = 5-(amidoglutaryl)-1,10-phenanthroline] has been synthesized and their DNA-binding characteristics examined. Single amino acid modifications were made from the parent metallointercalator−peptide conjugate [Rh(phi)_2(phen‘)]^(3+)-AANVAIAAWERAA-CONH_2, which targets 5‘-CCA-3‘ site-specifically. Moving the glutamate at position 10 in the sequence of the appended peptide to position 6 {[Rh(phi)_2(phen‘)]^(3+)-AANVAEAAWARAA-CONH_2} changed the sequence preference of the metallointercalator−peptide conjugate to 5‘-ACA-3‘. Subsequent mutation of the glutamate at position 6 to arginine {[Rh(phi)_2(phen‘)]^(3+)-AANVARAAWARAA-CONH_2} caused more complex changes in DNA recognition. Thermodynamic dissociation constants were determined for these metallointercalator−peptide conjugates by photoactivated DNA cleavage assays with the rhodium intercalators. At 55 °C in the presence of 5 mM MnCl_2, [Rh(phi)_2(phen‘)]^(3+)-AANVAIAAWERAA-CONH_2 binds to a 5‘-CCA-3‘ site with K_d = 5.7 × 10^(-8) M, whereas [Rh(phi)_2(phen‘)]^(3+)-AANVAEAAWARAA-CONH_2 binds to its target 5‘-ACA-3‘ site with K_d = 9.9 × 10^(-8) M. The dissociation constant for [Rh(phi)_2(phen‘)]^(3+) with random-sequence DNA is 7.0 × 10^(-7) M. Structural models have been developed and refined to account for the observed sequence specificities. As with much larger DNA-binding proteins, with these metal−peptide conjugate mimics, single amino acid changes can lead to single or multiple base changes in the DNA site targeted.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/bi982039aDOIArticle
http://pubs.acs.org/doi/abs/10.1021/bi982039aPublisherArticle
ORCID:
AuthorORCID
Barton, Jacqueline K.0000-0001-9883-1600
Additional Information:© 1999 American Chemical Society. Received August 24, 1998; Revised Manuscript Received June 4, 1999. Publication Date (Web): July 16, 1999. We are grateful to the NSF (Grant CHE-9422547) for financial support of this work. C.A.H. thanks W. R. Grace & Co. for a summer research fellowship. We thank the Biopolymer Synthesis and Analysis Center at Caltech for their technical assistance.
Funders:
Funding AgencyGrant Number
NSFCHE-9422547
W. R. Grace & Co.UNSPECIFIED
Issue or Number:31
DOI:10.1021/bi982039a
Record Number:CaltechAUTHORS:20160407-115523468
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20160407-115523468
Official Citation:Perturbing the DNA Sequence Selectivity of Metallointercalator−Peptide Conjugates by Single Amino Acid Modification Curtis A. Hastings and Jacqueline K. Barton* Biochemistry 1999 38 (31), 10042-10051 DOI: 10.1021/bi982039a
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:65990
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:11 Apr 2016 17:17
Last Modified:10 Nov 2021 23:52

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