Geoffrey Wickham
University of Wollongong
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Publication
Featured researches published by Geoffrey Wickham.
Australian Journal of Chemistry | 2003
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
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
Vincent Murray; H Motyka; Phillip R. England; Geoffrey Wickham; H H Lee; William A. Denny; W D McFadyen
Analyst | 2000
Paula Iannitti-Tito; Allan Weimann; Geoffrey Wickham; Margaret M. Sheil
Journal of Medicinal Chemistry | 1992
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
Joanne Whittaker; Vincent Murray; W. David McFadyen; Geoffrey Wickham; Laurence P. G. Wakelin
Journal of Medicinal Chemistry | 1990
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
Paula Iannitti; Margaret M. Sheil; Geoffrey Wickham
Nucleic Acids Research | 1993
Carleen Cullinane; Geoffrey Wickham; W. David McFadyen; William A. Denny; Brian D. Palmer; Don R. Phillips
Chemico-Biological Interactions | 1995
A.S. Prakash; Anthony G. Moore; Vincent Murray; Christina Matias; W. David McFadyen; Geoffrey Wickham