US Patent 10023605 Labeled nucleotide analogs having protein shields

Compositions, methods, and systems 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 nucleotide analogs have two avidin proteins connected by a central dye component, and each avidin protein is further connected to a nucleotide component. The protein can prevent 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.