Polymerase enzyme substrates with protein shield

摘要

Compositions and methods are provided for nucleotide analogs comprising protein shields for improving enzyme photostability in single molecule real time sequencing. Nucleotide analogs of the invention have a protein shield between the dye moieties and nucleotide moieties of the analog. The protein prevents the direct interaction of the dye moiety with the enzyme carrying out nucleotide synthesis preventing photodamage to the enzyme. The nucleotide analogs of the invention can have multiple dyes and multiple nucleotide moieties.

主权项

1. A labeled nucleotide analog comprising:
an avidin protein having four subunits, each subunit comprising one biotin binding site; one or two nucleotide components bound to the avidin protein, each comprising one or more phospholinked nucleotide moieties; and one or two dye components, bound to the avidin protein, each comprising one or more dye moieties; wherein each component is bound to the avidin protein through a biotin moiety attached to a binding site on the avidin protein; and wherein at least one of the nucleotide or dye components comprise a bis-biotin moiety bound to two of the biotin binding sites on the avidin protein.