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Jason R Betley

Publications and source records attributed to Jason R Betley.

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

Synthesis and use of a pseudo-cysteine for native chemical ligation.

The process of native chemical ligation (NCL) is well described in the literature. An N-terminal cysteine-containing peptide reacts with a C-terminal thioester-containing peptide to yield a native amide bond after transesterification and acyl transfer. An N-terminal cysteine is required as both the N-terminal amino function and the sidechain thiol participate in the ligation reaction. In certain circumstances it is desirable, or even imperative, that the N-terminal region of a peptidic reaction partner remain unmodified, for Instance for the retention of biological activity after ligation. This work discusses the synthesis of a pseudo-N-terminal cysteine building block for incorporation into peptides using standard methods of solid phase synthesis. Upon deprotection, this building block affords a de facto N-terminal cysteine positioned on an amino acid sidechain. which is capable of undergoing native chemical ligation with a thioester. The syntheses of several peptides and structures containing this motif are detailed, their reactions discussed. and further applications of this technology proposed.

Amino Acid Sequence↗