This invention belongs to the field of biotechnology, in particular to a mutant double-strand DNA (dsDNA) helicase protein nanopore derived from bovine papillomavirus and its application. The technical problem to be solved by this invention is to overcome the deficiency that the existing small-diameter protein nanopore requires an external strength or component to transport dsDNA. The technical scheme in this invention to solve the above deficiency is to provide a truncated E1-1 (306-577) protein, an E1-2 (306-605) protein and its variant derived from bovine papillomavirus double-stranded DNA helicase protein, as well as a variant of its homologous protein which is used for preparing membrane containing conductive channel, providing a new and effective choice for this field.
