Synthesis and characterization of a deuterium labeled stercobilin: A potential biomarker for autism.

Stercobilin is an end-stage metabolite of hemoglobin, a component of red blood cells. It has been found that there is a significantly lower concentration of stercobilin in the urine of people diagnosed with autism spectrum disorders, suggesting potential use as a biomarker. In vitro, we have synthesized stercobilin from its precursor bilirubin through a reduction reaction proceeded by an oxidation reaction.

Zn2+-dependent deoxyribozymes that form natural and unnatural RNA linkages.

We report Zn(2+)-dependent deoxyribozymes that ligate RNA. The DNA enzymes were identified by in vitro selection and ligate RNA with k(obs) up to 0.5 min(-)(1) at 1 mM Zn(2+) and 23 degrees C, pH 7.

Structure-function correlations derived from faster variants of a RNA ligase deoxyribozyme.

We previously reported the in vitro selection of several Mg2+-dependent deoxyribozymes (DNA enzymes) that synthesize a 2'-5' RNA linkage from a 2',3'-cyclic phosphate and a 5'-hydroxyl. Here we subjected the 9A2 deoxyribozyme to re-selection for improved ligation rate. We found two new DNA enzymes (7Z81 and 7Z48) that contain the catalytic core of 7Q10, a previously reported small deoxyribozyme that is unrelated in sequence to 9A2.

In vitro evolution of an RNA-cleaving DNA enzyme into an RNA ligase switches the selectivity from 3'-5' to 2'-5'.

Deoxyribozymes that ligate RNA expand the scope of nucleic acid catalysis and allow preparation of site-specifically modified RNAs. Previously, deoxyribozymes that join a 5'-hydroxyl and a 2',3'-cyclic phosphate were identified by in vitro selection from random DNA pools. Here, the alternative strategy of in vitro evolution was used to transform the 8-17 deoxyribozyme that cleaves RNA into a family of DNA enzymes that ligate RNA.

Deoxyribozymes with 2'-5' RNA ligase activity.

In vitro selection was used to identify deoxyribozymes that ligate two RNA substrates. In the ligation reaction, a 2'-5' RNA phosphodiester linkage is created from a 2',3'-cyclic phosphate and a 5'-hydroxyl group. The new Mg(2+)-dependent deoxyribozymes provide 50-60% yield of ligated RNA in overnight incubations at pH 7.