| abstract |
Mycobacterium smegmatis-porin (Msp) having a vestibule and a constriction zone defining a tunnel, said Msp comprising a mutant MspA, negative charges being removed from the constriction zone of the Msp compared to the constriction zone of a wild type Msp, and wherein the Msp comprises a positively charged amino acid replacing a negatively charged amino acid located in the vestibule of a wild-type Msp. |