Minisatellite telomeres occur in the family Alliaceae but are lost in Allium.

Although telomere sequences are considered to be highly conserved, there are switch-points in plant telomere evolution that are congruent with species' phylogenies. When Asparagales diverged, the Arabidopsis-type telomeric minisatellite repeat (TTTAGGG)(n) was first replaced by a human-type (TTAGGG)(n) repeat, and both were lost in Allium cepa (Alliaceae). We aimed to discover (1) when this loss occurred during divergence of Alliaceae and, (2) if (TTAGGG)(n) repeats were replaced by other known telomeric minisatellites.

Comparison of different kinds of probes used for analysis of variant telomeric sequences.

In this work we aimed to compare and critically evaluate results obtained by different types of probes used for hybridisation to detect variant telomeric sequences with respect to their reliability and information value. Using slot-blot hybridisation we investigated three types of probes (oligonucleotides, cloned fragments and concatenated probes) under various conditions of hybridisation and washing. The concatenated probes exhibited the highest specificity although all three types are suitable for hybridisation of telomeric sequences under appropriate experimental conditions.

A comparison of DNA binding profiles of dinuclear platinum compounds with polyamine linkers and the trinuclear platinum phase II clinical agent BBR3464.

The DNA binding profiles of three bis Pt(II) polyamine-linked compounds, [[ trans-PtCl(NH(3))(2)](2)[mu-spermine- N(1), N(12)]](4+), [[ trans-PtCl(NH(3))(2)](2)[mu-spermidine- N(1), N(8)]](3+), and [[ trans-PtCl(NH(3))(2)](2)[mu-BOC-spermidine]](2+), were compared with that of a novel trinuclear phase II clinical agent, [[ trans-PtCl(NH(3))(2)](2)[mu- trans-Pt(NH(3))(2)(H(2)N(CH(2))(6)NH(2))(2)]](4+). All of the compounds bind preferentially in a bifunctional manner, according to unwinding of supercoiled DNA circles. The kinetics of binding of these compounds corresponds to their relative charge (2+ to 4+).

Steric control of DNA interstrand cross-link sites of trans platinum complexes: specificity can be dictated by planar nonleaving groups.

Recent findings that novel trans-dichloroplatinum(II) complexes exhibit antitumor activity violate the classical structure-activity relationships of platinum(II) complexes. These novel "nonclassical" trans platinum complexes also comprise those containing planar aromatic amines. Initial studies have shown that these compounds form a considerable amount of DNA interstrand cross-links (up to approximately 30%) with a rate markedly higher than clinically ineffective transplatin.

DNA interactions of new antitumor aminophosphine platinum(II) complexes.

Mechanistic studies are presented of a novel class of aminophosphine platinum(II) complexes as potential anticancer agents. These new agents, which have demonstrated activity against murine and human tumor cells including those resistant to cisplatin are cis-[PtCl2(Me2N(CH2)3PPh2-P)2] (Com1) and cis-[PtCl(C6H11NH(CH2)2PPh2-N,P)(C6H11NH(CH2) 2PPh2-P)] (Com2). We studied modifications of natural and synthetic DNAs in cell-free media by Com1 and Com2 by various biomedical and biophysical methods and compared the results with those obtained when DNA was modified by cisplatin.