Labeled nucleotide analogs, reaction mixtures, and methods and systems for sequencing
Labeled nucleotide analogs comprising at least one avidin protein, at least one dye-labeled compound, and at least one nucleotide compound are provided. The analogs are useful in various fluorescence-based analytical methods, including the analysis of highly multiplexed optical reactions in large numbers at high densities, such as single molecule real time nucleic acid sequencing reactions. The analogs are detectable with high sensitivity at desirable wavelengths. They contain structural components that modulate the interactions of the analogs with DNA polymerase, thus decreasing photodamage and improving the kinetic and other properties of the analogs in sequencing reactions. Also provided are nucleotide and dye-labeled compounds of the subject analogs, as well as intermediates useful in the preparation of the compounds and analogs. Compositions comprising the compounds, methods of synthesis of the intermediates, compounds, and analogs, and mutant DNA polymerases are also provided.
1. A labeled nucleotide analog comprising:
a first avidin protein having four subunits, each subunit comprising one biotin binding site;
a first nucleotide compound bound to the first avidin protein, the first nucleotide compound represented by structural formula (I):
wherein
L is a nucleotide linker element and comprises an affinity modulating element;
P is a polyphosphate element;
Nu is a nucleoside element;
X is a multivalent central core element;
B″ is a terminal coupling element and comprises a biotin moiety;
n is an integer from 1 to 4; and
o is 0 or 1; and
a first dye-labeled compound bound to the first avidin protein, the first dye-labeled compound comprising a donor dye, an acceptor dye, a terminal coupling element, and a dye compound linker element.
2. The labeled nucleotide analog of claim 1 , wherein the first dye-labeled compound and the first nucleotide compound are each bound to the first avidin protein through a biotin moiety.
3. The labeled nucleotide analog of claim 1 , further comprising a second avidin protein and a second nucleotide compound, wherein
the second avidin protein is bound to the first dye-labeled compound through a biotin moiety and to the second nucleotide compound through a biotin moiety.
4. The labeled nucleotide analog of claim 1 , wherein the first avidin protein is avidin, streptavidin, tamavidin, traptavidin, xenavidin, bradavidin, AVR2, AVR4, or a homolog thereof.
5. The labeled nucleotide analog of claim 1 , wherein the donor dye and the acceptor dye are fluorescent dyes.
6. The labeled nucleotide analog of claim 1 , wherein the affinity modulating element is an aromatic spacer element or a shield element.
7. The labeled nucleotide analog of claim 6 , wherein the affinity modulating element is an aromatic spacer element.
8. The labeled nucleotide analog of claim 7 , wherein the aromatic spacer element is a substituted or unsubstituted monocyclic, bicyclic, or tricyclic aromatic moiety.
9. The labeled nucleotide analog of claim 8 , wherein the aromatic spacer element is represented by structural formula (II):
wherein
the A-ring and the B-ring is each independently a 5-7 atom cyclic structure, wherein at least one of the A-ring or the B-ring is aromatic; and
the A-ring or the B-ring optionally comprises at least one anionic substituent.
10. The labeled nucleotide analog of claim 9 , wherein the optional at least one anionic substituent is —SO 3 H.
11. The labeled nucleotide analog of claim 9 , wherein the aromatic spacer element is represented by structural formula (IIA) or (IIB):
wherein
one of the A 1 , A 2 , A 3 , and A 4 groups is
and the other groups are —CH 2 — or a bond; and
R 1 is H or an anionic substituent and R 2 is H or an anionic substituent.
12. The labeled nucleotide analog of claim 11 , wherein the anionic substituent is —SO 3 H.
13. The labeled nucleotide analog of claim 11 , wherein the aromatic spacer element is represented by structural formula (IIC) or (IIC′):
14. The labeled nucleotide analog of claim 11 , wherein the aromatic spacer element is represented by one of the following structural formulae:
15. The labeled nucleotide analog of claim 7 , wherein L further comprises an alkyl linker group, optionally comprising an amide bond.
16. The labeled nucleotide analog of claim 7 , wherein L further comprises a triazole.
17. The labeled nucleotide analog of claim 7 , wherein B″ comprises a biotin moiety.
18. The labeled nucleotide analog of claim 17 , wherein B″ comprises a bis-biotin moiety.
19. The labeled nucleotide analog of claim 7 , wherein o is 1.
20. The labeled nucleotide analog of claim 19 , wherein X comprises a polyamine moiety.
21. The labeled nucleotide analog of claim 7 , wherein the at least one nucleotide compound does not contain a dye.
22. The labeled nucleotide analog of claim 7 , wherein L comprises at least one shield element.
23. The labeled nucleotide analog of claim 6 , wherein the affinity modulating element is a shield element.
24. The labeled nucleotide analog of claim 6 , wherein the shield element comprises a plurality of side chains.
25. The labeled nucleotide analog of claim 24 , wherein at least one side chain has a molecular weight of at least 300.
26. The labeled nucleotide analog of claim 24 , wherein at least one side chain comprises a negatively-charged component.
27. The labeled nucleotide analog of claim 26 , wherein the negatively-charged component comprises a sulfonic acid.
28. The labeled nucleotide analog of claim 24 , wherein at least one side chain comprises a substituted phenyl group.
29. The labeled nucleotide analog of claim 24 , wherein at least one side chain comprises a triazole.
30. The labeled nucleotide analog of claim 23 , wherein L further comprises an alkyl linker group, optionally comprising an amide bond.
31. The labeled nucleotide analog of claim 23 , wherein L further comprises a triazole.
32. The labeled nucleotide analog of claim 23 , wherein B″ comprises a biotin moiety.
33. The labeled nucleotide analog of claim 32 , wherein B″ comprises a bis-biotin moiety.
34. The labeled nucleotide analog of claim 23 , wherein the at least one nucleotide compound does not contain a dye.
35. The labeled nucleotide analog of claim 23 , wherein L further comprises an aromatic spacer element.