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Biomedical subjects

A Guy

Publications and source records attributed to A Guy.

47 records · Page 3Linked to original sources
PubMed1980

Specific in vitro transcription of conalbumin gene is drastically decreased by single-point mutation in T-A-T-A box homology sequence.

A single-point mutation, consisting of a T-to-G transversion, was made in the third nucleotide of the conalbumin gene T-A-T-A-A-A-A homology sequence (the T-A-T-A or Goldberg-Hogness box). In an in vitro system, specific transcription of the mutant DNA was drastically decreased compared to the normal gene. This down-mutation is consistent with the idea that the T-A-T-A box is an important element for specific initiation of transcription.

Animals↗
PubMed1980

A novel class of condensing reagents in phosphodiester oligodeoxyribonucleotides synthesis. Application of the constituents of free terminal carboxy oxytocine gene.

Benzotriazol-1-yl-oxy-tris (dimethylamino) phosphonium salts have been used as novel condensing agents to promote internucleotide bond formation in phosphotriester oligodeoxyribonucleotide synthesis. The effectiveness of these stable compounds has been shown by the synthesis of the six oligodeoxyribonucleotide building blocks of the carboxy terminal oxytocine gene. Some modifications incorporated in the phosphotriester method include a rapid procedure to prepare the fully protected dideoxyribonucleotide blocks and size exclusion chromatography of the deprotected oligodeoxyribonucleotides. The triester oligodeoxyribonucleotides were studied by chemical ionization mass spectrometry.

Base Sequence↗
PubMedDate not supplied

[Synthesis of a DNA fragment containing dihydro-5,6 thymine].

The preparation of a pentadecanucleoside tetradecaphosphate containing the modified base 5,6-dihydrothymine (DHT) is reported herein. The synthesis was performed with a mixture of diastereoisomers (5R and 5S), obtained by catalytic hydrogenation of thymidine. The phosphorylated protected monomer was characterized by proton NMR and FAB mass spectrometry. It was introduced into the DNA fragment (poly dT) by the solid phase phosphotriester approach. After deprotection, the determination of the site of the modified base in the chain was made using different methods. The classical chemical sequencing method of Maxam and Gilbert showed no difference with respect to thymine moieties in the pentadecamer. To characterize the presence and the location of the modified base DHT, the 32P 5'-end labelled pentadecamer was heated in formic acid at 90 degrees C and length separated by polyacrylamide gel electrophoresis. The Electronic Impact mass spectrometry under pyrolytic conditions of the 15-mer showed that the modified base was present in the deprotected DNA fragment.

Base Sequence↗