Msp nanopores and related methods

摘要

Provided herein are Mycobacterium smegmatis porin nanopores, systems that comprise these nanopores, and methods of using and making these nanopores. Such nanopores may be wild-type MspA porins, mutant MspA porins, wild-type MspA paralog porins, wild-type MspA homolog porins, mutant MspA paralog porins, mutant MspA homolog porins, or single-chain Msp porins. Also provided are bacterial strains capable of inducible Msp porin expression.

主权项

1. A method for determining an identity of one or more nucleotides in a nucleic acid, the method comprising:
translocating the nucleic acid from a first conductive liquid medium to a second conductive liquid medium in liquid communication through a mutant Mycobacterium smegmatis porin A (MspA) comprising a mutant MspA monomer with an amino acid sequence of SEQ ID NO:1 and further comprising (i) mutations such that positions 90 and 91 contain amino acids with a neutral charge, and (ii) one or more mutations adding a positively charged amino acid to a vestibule or entrance of the MspA; measuring an ion current between the first conductive liquid medium and the second conductive liquid medium as nucleotides in the nucleic acid pass through the mutant MspA, thereby producing current patterns in the measured ion current; and determining the identity of one or more nucleotides in the nucleic acid based on reference current patterns from known nucleotides.