Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Patent
1996-02-01
1999-04-06
Wilson, James O.
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
536 253, 536 2531, 536 254, 536 2541, 585500, C07H 2104, C07C 4321, C07C 3334
Patent
active
058920072
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a new protecting group and its use, in particular, in oligodeoxyribonucleotide synthesis. It relates more particularly to a protective group facilitating the purification of compounds, especially oligodeoxyribonucleotides (or oligonucleotides as more frequently known) during or at the end of a synthesis.
BACKGROUND OF THE INVENTION
Oligonucleotides are part of the sequence of a molecule of DNA. DNA is a polynucleotide; a polymer built of nucleotide units, each comprising a phosphate group, a sugar (deoxyribose), and a base (adenine, guanine, cytosine or thymine). DNA molecules form a double helix with the two strands held together by hydrogen bonds between specific base pairs: adenine always pairs with thymine and guanine with cytosine. Thus the sequence of one strand of the helix determines the sequence of the other:
The sequence of a particular piece of DNA might represent part of a gene which `encodes`, and thus directs the production of, a particular protein. Protein production is mediated via an RNA copy of this DNA (with uracil in place of thymine), where the order of these bases defines the order in which the amino acids are joined together to form proteins. Because there are 20 amino acids but only four bases, it follows that a group of bases is needed to code for one amino acid. These groups are comprised of three bases called `codons`. Thus methionine is coded for by ATG, histidine by CAT, lysine by AAA, proline by CCT etc, and the DNA sequence .sup.5 'ATGAAACCTCATAAA .sup.3 ' codes for the amino-acid sequence Met-Lys-Pro-His-Lys. Altering the DNA sequence by substituting one base for another can alter the encoded amino acid sequence. For example, if the CCT codon in the DNA sequence .sup.5 'ATGAAACCTCATAAA .sup.3 ' is changed to CAT (a single nucleotide C to A substitution) the resulting amino acid sequence changes from Met-Lys-Pro-His-Lys to Met-Lys-His-His-Lys. This ability to change, or `mutate`, the nucleotide sequence of a gene or DNA fragment is the basis behind the technique known as site-directed mutagenesis. A known DNA sequence is usually mutated with the aid of a synthetic oligonucleotide and is therefore often called oligonucleotide-directed mutagenesis.
The critical feature of site-directed mutagenesis is that it allows pre-designed mutations to be specifically introduced into a target gene. With the structures of many important proteins having been determined at atomic resolution, particularly by X-ray crystallography but also by NMR spectroscopy, it is possible to analyze the structure and function of enzymes in great detail. The importance of one or more amino acid residue can be assessed by engineering specific modifications into the protein structure. Most commonly the mutations involve single base substitutions but it is also possible to construct deletions and insertions in the DNA sequence, resulting in shorter or longer polypeptides.
It can therefore be seen that there is a need to be able to synthesise oligonucleotide sequences of a high purity. Further information regarding site directed mutagenesis is to be found in an article by Chapman and Reid in Chemistry in Britain, March 1993, p 202-204.
In organic synthesis, in particular multi-step, organic synthesis, the purification of the products obtained can present more problems than the synthesis itself. This is particularly true in the case of oligonucleotide synthesis, a synthesis which systematically uses protective groups which can also play supplementary roles. One solution to this problem would be to modify the oligonucleotide, or any other molecule requiring protection, by binding it to a solid in a manner which is physically reversible, in the course of working up and purification. To date no protective group has been disclosed as being capable of exercising such a property.
GB-A-2251242 (Ramage et al) describes a protecting group for use in peptide synthesis. The protecting group is of formula Ar--L-- where Ar represents a substantially plane, fused ring system containing at lea
REFERENCES:
fluorenylmethyl)-4',4"-Dimethoxytrityl Chloride: A Hydrophobic 5'-Protecting Group for the Separation of Synthetic Oligonucleotides", vol. 34, 1993, pp. 7133-7136.
E. Happ et al., Nucleosides & Nucleotides, "New Trityl-based Protecting Groups with a Mild Two-Step Removal", vol. 7, 1988, pp. 813-816.
Laporte PLC
Wilson James O.
LandOfFree
Method and means for oligonucleotide separation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and means for oligonucleotide separation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and means for oligonucleotide separation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1372395