Selectively controllable cleavable linkers
Selectively controllable cleavable linkers include electrochemically-cleavable linkers, photolabile linkers, thermolabile linkers, chemically-labile linkers, and enzymatically-cleavable linkers. Selective cleavage of individual linkers may be controlled by changing local conditions. Local conditions may be changed by activating electrodes in proximity to the linkers, exposing the linkers to light, heating the linkers, or applying chemicals. Selective cleaving of enzymatically-cleavable linkers may be controlled by designing the sequences of different sets of the individual linkers to respond to different enzymes. Cleavable linkers may be used to attach polymers to a solid substrate. Selective cleavage of the linkers enables release of specific polymers from the solid substrate. Cleavable linkers may also be used to attach protecting groups to the ends of growing polymers. The protecting groups may be selectively removed by cleavage of the linkers to enable growth of specific polymers.
1. A selectively-cleavable two-stage surface linker comprising:
a point of attachment to a substrate;
a first amide bond;
a second amide bond;
an allyl group connected to the nitrogen of the first amide bond; and
a point of attachment to a polymer chain, wherein the polymer chain is an oligonucleotide or a polymer other than a polypeptide;
wherein, the linker is configured such that cleavage at a first cleavage location separates the allyl group from the nitrogen of the first amide bond exposes a second cleavage location that is the first amide bond to cleavage by a peptidase.
2. The selectively-cleavable two-stage surface linker of claim 1 , further comprising a spacer between the second amide bond and the polymer chain.
3. The selectively-cleavable two-stage surface linker of claim 2 , wherein the spacer comprises an aliphatic spacer, an alkyl spacer, an aromatic spacer, an alkylene glycol, a polyethylene glycol, a carbohydrate, or a PEG spacer.
4. The selectively-cleavable two-stage surface linker of claim 1 , further comprising a first side chain between the first amide bond and the point of attachment to the substrate, wherein the first side chain comprising one or more amino acid side chains.
5. The selectively-cleavable two-stage surface linker of claim 1 , further comprising a second side chain between the first amide bond and the second amide bond, wherein the second side chain comprising one or more amino acid side chains.
6. The selectively-cleavable two-stage surface linker of claim 1 , further comprising a third side chain from the nitrogen of the second amide bond, wherein the third side chain is a hydrogen or an allyl group.
7. The selectively-cleavable two-stage surface linker of claim 1 , having the following structure:
wherein R 1 , R 2 , and R 3 are all independently organic groups comprising at least one hydrogen.
8. The selectively-cleavable two-stage surface linker of claim 7 , wherein R 1 and R 2 are both independently one or more amino acid side chains and R 3 is hydrogen or an allyl group.
9. The selectively-cleavable two-stage surface linker of claim 1 , wherein the polymer chain is an oligonucleotide.