Biomedical subjects

Douglas J Dellinger

Publications and source records attributed to Douglas J Dellinger.

3 recordsLinked to original sources

PubMed2003

Solid-phase oligodeoxynucleotide synthesis: a two-step cycle using peroxy anion deprotection.

A novel solid-phase phosphoramidite based oligodeoxynucleotide two-step synthesis method has been developed. Keys to this method are replacement of the 5'-dimethoxytrityl blocking group with an aryloxycarbonyl and the use of N-dimethoxytrityl protection for the exocyclic amines of adenine and cytosine. With these modifications, coupling of each 2'-deoxynucleoside 3'-phosphoramidite to the growing oligodeoxynucleotide on the solid support can be followed by treatment with an aqueous mixture of peroxy anions buffered at pH 9.6. This reagent effectively removes the carbonate protecting group and simultaneously oxidizes the phosphite internucleotide linkage. As a consequence a new two-step synthesis cycle is possible. Oligodeoxynucleotides synthesized using this approach are identical to authentic samples when tested by a variety of analytical techniques.

Anions↗

PubMed2003

Biochemical properties of phosphonoacetate and thiophosphonoacetate oligodeoxyribonucleotides.

Phosphorus-modified phosphonoacetate and thiophosphonoacetate oligodeoxyribonucleotides were chemically synthesized and their biochemical properties evaluated. Under physiological pH, these DNA analogs possess negative charge and form stable, complementary A-like DNA:RNA heteroduplexes when analyzed via circular dichroism spectroscopy. Phosphonoacetate and thiophosphonoacetate oligomers were found to stimulate RNase H activity and to be completely resistant to degradation by snake venom phosphodiesterase, DNase I and HeLa cell nuclear extract. Further research has demonstrated that neutral, esterified forms of these analogs can be taken up by cells. Phosphonoacetate and thiophosphonoacetate oligomers therefore represent a new class of oligodeoxyribonucleotide analogs having phosphorus- carbon bonds with considerable potential for use in biological research.

Chromatography, High Pressure Liquid↗

PubMed2003

Solid-phase chemical synthesis of phosphonoacetate and thiophosphonoacetate oligodeoxynucleotides.

Phosphonoacetate and thiophosphonoacetate oligodeoxynucleotides were prepared via a solid-phase synthesis strategy. Under Reformatsky reaction conditions, novel esterified acetic acid phosphinodiamidites were synthesized and condensed with appropriately protected 5'-O-(4, 4'-dimethoxytrityl)-2'-deoxynucleosides to yield 3'-O-phosphinoamidite reactive monomers. These synthons when activated with tetrazole were used with an automated DNA synthesizer to prepare phosphonoacetic acid modified internucleotide linkages on controlled pore glass. The phosphinoacetate coupling products were quantitatively oxidized at each step with (1S)-(+)-(10-camphorsulfonyl)oxaziridine or 3H-1,2-benzodithiol-3-one-1,1-dioxide to produce mixed sequence phosphonoacetate and thiophosphonoacetate oligodeoxynucleotides with an average per cycle coupling efficiency of greater than 97%. Completely deprotected, modified oligodeoxynucleotides were purified by reverse-phase HPLC and characterized by ion exchange HPLC, (31)P NMR, and MALDI/TOF mass spectroscopy. Both analogues were stable toward hydrolysis with snake venom phosphodiesterase and stimulated RNase H1 activity.

Chromatography, High Pressure Liquid↗