Substrates for covalent tethering of proteins to functional groups or solid surfaces
The present invention provides haloalkane substrates, and linkers for connecting such substrates to functional elements (e.g., tags, labels, surfaces, etc.). Substrates and linkers described herein find use, for example, in labeling, detection, and immobilization of proteins, cells, and molecules. In particular, the linkers provided herein find use within substrates for dehalogenase variants that form covalent bonds with their haloalkane substrates.
1. A cell permeable compound of formula R-L1-M-L2-A-X;
wherein R is a functional group selected from an affinity tag, a fluorophore, a chromophore, a cross-linking group, an amino acid, a peptide, a polypeptide, a nucleotide, and a lipid; wherein R is not 1, 4, 7-triazacyclononane-N, N′, N″-triacetic acid (NOTA);
wherein M is a first carbamate group;
wherein L1 is a first linker portion that comprises a second carbamate group; wherein the second carbamate group is separated from R by 2 or more linearly connected atoms; wherein the second carbamate group is separated from M by 2 or more linearly connected atoms;
wherein L2 is a second linker portion;
wherein A is (CH 2 ) 6 ; and X is a halogen; and
wherein L2-A separates M and X by 6-18 linearly connected atoms.
2. The compound of claim 1 , wherein L2-A separates M and X by 12 linearly connected atoms.
3. The compound of claim 1 , wherein the functional group comprises an affinity tag or fluorophore.
4. The compound of claim 1 , wherein L2 does not comprise a carbamate group.
5. The compound of claim 1 , wherein L2 comprises linearly connected CH 2 and O groups.
6. The compound of claim 5 , wherein L2 consists of linearly connected CH 2 and O groups.
7. The compound of claim 5 , wherein L2 comprises ((CH 2 ) 2 O) x , wherein x=0-5.
8. The compound of claim 7 , wherein L2 comprises ((CH 2 ) 2 O) 2 .
9. The compound of claim 1 , wherein L1 comprises linearly connected CH 2 and O groups.