Biomedical subjects

R T Pon

Publications and source records attributed to R T Pon.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Cytarabine-induced destabilization and bending of a model Okazaki fragment.

The effects of cytarabine on the structural and thermodynamic properties of an Okazaki fragment were investigated using UV hyperchromicity and 2D 1H NMR. Cytarabine significantly decreased the stability of this model Okazaki fragment, decreasing the melting temperature from 46.8 degrees C to 42.4 degrees C at 1.33 x 10(-5) M. Cytarabine also markedly increased the bend angle of the Okazaki fragment duplex from 20 degrees to 42 degrees. Changes to the structures and stabilities of Okazaki fragments may cause the biological effects of cytarabine.

Antimetabolites, Antineoplastic↗

PubMedDate not supplied

Cytotoxicity and in-vivo tolerance of FdUMP[10]: a novel pro-drug of the TS inhibitory nucleotide FdUMP.

The cytotoxicity of the 10mer ODN FdUMP[10] towards human colorectal tumor cells was evaluated using a clonogenic assay. FdUMP[10] was more than 100-fold more active than 5-FU at inhibiting colony formation of H630 cells. FdUMP[10] was also evaluated for cytotoxicity in the NCI 60 cell line screen, and showed markedly improved activity relative to 5-FU against numerous tumor cell lines. The in-vivo tolerance of FdUMP[10] is more than three-fold greater per mole fluorinated pyrimidine, than 5-FU.

Antineoplastic Agents↗

PubMedDate not supplied

Properties of arabinonucleic acids (ANA & 20'F-ANA): implications for the design of antisense therapeutics that invoke RNase H cleavage of RNA.

Inversion of configuration of the C2' position of RNA leads to a very unique nucleic acid structure: arabinonucleic acid (ANA). ANA, and its 2'-fluoro derivative (2'F-ANA) from hybrids with RNA that are capable of activating RNase H, resulting in cleavage of the RNA strand. In this paper, we review the properties of duplexes formed between ANA (or 2'F-ANA) and its RNA complement. These studies support the notion that RNase H is sensitive to the minor groove dimensions of the hybrid substrate.

Arabinonucleotides↗

PubMedDate not supplied

Multiple oligonucleotide synthesis in tandem on solid-phase supports for small and large scale synthesis.

Multiple oligonucleotides linked end-to-end in tandem can be synthesized by adding a nucleoside to the 5'-OH end of a prior sequence. Nucleosides with 3'-succinyl or Q-Linker arms are coupled with HBTU/DMAP. Alternatively, new phosphoramidite reagents with 3'-ester linkages can be used. Hydroxyl or amino supports can also be used as universal starting materials. Treatment with NH4OH cleaves the 3'-ester to yield only 3'-OH groups and no unwanted 3'-phosphorylated products occur.

Cross-Linking Reagents↗