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Dive into the research topics where Geoffrey Wickham is active.

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Featured researches published by Geoffrey Wickham.


Australian Journal of Chemistry | 2003

Rapid Determination of Sequence Selectivity and Stability of Alkylated Oligonucleotide Adducts by Electrospray Tandem Mass Spectrometry

Michelle L. Colgrave; Paula Iannitti-Tito; Geoffrey Wickham; Margaret M. Sheil

The binding of the antitumor antibiotics, duocarmycin C2 (pyrindamycin A), duocarmycin C1 (pyrindamycin B), hedamycin, and DC92-B to self complementary oligonucleotides (ranging from 6 to 14-mers) has been studied using electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS). The duocarmycins bind via non-covalent interactions in the minor groove of DNA with subsequent alkylation of the N3 atom of adenine. Hedamycin and DC92-B are intercalating, alkylating agents that target the N7 of guanines within 5′-CGT, and to a lesser extent, 5′-CGG sequences. We show here that the site(s) of alkylation by these ligands are strongly influenced by the location of high affinity binding sites within these short oligonucleotides. These data clearly demonstrate value of using ESI-MS/MS to pre-screen ligand–oligonucleotide complexes prior to performing more detailed structural studies, since subtle selectivity differences have been detected by this technique that were not evident from conventional sequencing studies on larger segments of DNA.


FEBS Letters | 1995

The observation of a hedamycin-d(CACGTG)2 covalent adduct by electrospray mass spectrometry

Geoffrey Wickham; Paula Iannitti; Jacqueline Boschenok; Margaret M. Sheil

Covalent binding of the antitumour antibiotic hedamycin to the self‐complementary hexadeoxyribonucleotide 5′‐CACGTG‐3′ has been investigated by electrospray ionization mass spectrometry (ESI‐MS). Ions due to double‐stranded forms of the free 5′‐CACGTG‐3′ and the hedamycin‐5′‐CACGTG‐3′ adduct have been observed in ESI mass spectra and their identity has been confirmed by resolution of individual charge states in ESI‐MS spectra. Clear evidence that specific base‐paired associations are being observed in ESI‐MS is provided by the results of a titration experiment involving alkylated and non‐alkylated complementary strands. This work demonstrates the potential of this powerful new tool for studying ligand‐DNA binding.


Journal of Biological Chemistry | 1992

The use of Taq DNA polymerase to determine the sequence specificity of DNA damage caused by cis-diamminedichloroplatinum(II), acridine-tethered platinum(II) diammine complexes or two analogues.

Vincent Murray; H Motyka; Phillip R. England; Geoffrey Wickham; H H Lee; William A. Denny; W D McFadyen


Analyst | 2000

Structural analysis of drug–DNA adducts by tandemmass spectrometry

Paula Iannitti-Tito; Allan Weimann; Geoffrey Wickham; Margaret M. Sheil


Journal of Medicinal Chemistry | 1992

DNA-directed alkylating agents. 5. Acridinecarboxamide derivatives of (1,2-diaminoethane)dichloroplatinum(II)

Ho H. Lee; Brian D. Palmer; Bruce C. Baguley; Michael Chin; W. David McFadyen; Geoffrey Wickham; Deborah Thorsbourne-Palmer; Laurence P. G. Wakelin; William A. Denny


Nucleic Acids Research | 1998

The interaction of DNA-targeted platinum phenanthridinium complexes with DNA

Joanne Whittaker; Vincent Murray; W. David McFadyen; Geoffrey Wickham; Laurence P. G. Wakelin


Journal of Medicinal Chemistry | 1990

DNA-directed alkylating agents. 2. Synthesis and biological activity of platinum complexes linked to 9-anilinoacridine

Brian D. Palmer; Ho H. Lee; P. Johnson; Bruce C. Baguley; Geoffrey Wickham; Laurence P. G. Wakelin; W. D. Mcfadyen; William A. Denny


Journal of the American Chemical Society | 1997

High Sensitivity and Fragmentation Specificity in the Analysis of Drug−DNA Adducts by Electrospray Tandem Mass Spectrometry

Paula Iannitti; Margaret M. Sheil; Geoffrey Wickham


Nucleic Acids Research | 1993

The use of bidirectional transcription footprinting to detect platinum-DNA crosslinks by acridine-tetheredplatinum diamine complexes and cisplatin

Carleen Cullinane; Geoffrey Wickham; W. David McFadyen; William A. Denny; Brian D. Palmer; Don R. Phillips


Chemico-Biological Interactions | 1995

Comparison of the sequence selectivity of the DNA-alkylating pluramycin antitumour antibiotics DC92-B and hedamycin

A.S. Prakash; Anthony G. Moore; Vincent Murray; Christina Matias; W. David McFadyen; Geoffrey Wickham

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Vincent Murray

University of New South Wales

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Christina Matias

University of New South Wales

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Anthony G. Moore

University of New South Wales

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Paula Iannitti

University of Wollongong

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