Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L135I in the mature alpha-hemolysin amino acid sequence. The ?-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.

Abstract: The present disclosure provides variant OmpG polypeptides, compositions comprising the OmpG variant polypeptides, and methods for using the variant OmpG polypeptides as nanopores for determining the sequence of single stranded nucleic acids. The variant OmpG nanopores reduce the ionic current noise versus the parental OmpG polypeptide from which they are derived and thereby enable sequencing of polynucleotides with single nucleotide resolution. The reduced ionic current noise also provides for the use of these OmpG nanopore variants in other single molecule sensing applications, e.g., protein sequencing.

Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L135I in the mature alpha-hemolysin amino acid sequence. The ?-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.

Abstract: The present disclosure provides variant OmpG polypeptides, compositions comprising the OmpG variant polypeptides, and methods for using the variant OmpG polypeptides as nanopores for determining the sequence of single stranded nucleic acids. The variant OmpG nanopores reduce the ionic current noise versus the parental OmpG polypeptide from which they are derived and thereby enable sequencing of polynucleotides with single nucleotide resolution. The reduced ionic current noise also provides for the use of these OmpG nanopore variants in other single molecule sensing applications, e.g., protein sequencing.

Abstract: The present disclosure provides variant OmpG polypeptides, compositions comprising the OmpG variant polypeptides, and methods for using the variant OmpG polypeptides as nanopores for determining the sequence of single stranded nucleic acids. The variant OmpG nanopores reduce the ionic current noise versus the parental OmpG polypeptide from which they are derived and thereby enable sequencing of polynucleotides with single nucleotide resolution. The reduced ionic current noise also provides for the use of these OmpG nanopore variants in other single molecule sensing applications, e.g., protein sequencing.

Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L135I in the mature alpha-hemolysin amino acid sequence. The ?-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.

Abstract: The present disclosure provides variant OmpG polypeptides, compositions comprising the OmpG variant polypeptides, and methods for using the variant OmpG polypeptides as nanopores for determining the sequence of single stranded nucleic acids. The variant OmpG nanopores reduce the ionic current noise versus the parental OmpG polypeptide from which they are derived and thereby enable sequencing of polynucleotides with single nucleotide resolution. The reduced ionic current noise also provides for the use of these OmpG nanopore variants in other single molecule sensing applications, e.g., protein sequencing.

Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L135I in the mature alpha-hemolysin amino acid sequence. The ?-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.

Abstract: Described herein are nanopore protein conjugates that can be used in DNA sequencing reactions. The nanopore protein conjugates includes a nanopore protein monomer that is joined to a DNA binding domain. The nanopore protein monomer is available to oligomerize with other nanopore protein monomers, while the DNA binding domain is available to bind to a template DNA strand. In certain examples, the nanopore protein monomer is an alpha-hemolysin monomer or variant thereof and the DNA binding domain is an Sso7d protein or variant thereof, such as an Sso7d-like protein. Also provided are nanopore protein assemblies incorporating the nanopore protein conjugates, along with methods of using the nanopore protein assemblies in sequencing reactions.

Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L1351 in the mature alpha-hemolysin amino acid sequence. The ?-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.

Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L1351 in the mature alpha-hemolysin amino acid sequence. The ?-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.

Abstract: The present disclosure provides variant OmpG polypeptides, compositions comprising the OmpG variant polypeptides, and methods for using the variant OmpG polypeptides as nanopores for determining the sequence of single stranded nucleic acids. The variant OmpG nanopores reduce the ionic current noise versus the parental OmpG polypeptide from which they are derived and thereby enable sequencing of polynucleotides with single nucleotide resolution. The reduced ionic current noise also provides for the use of these OmpG nanopore variants in other single molecule sensing applications, e.g., protein sequencing.

Abstract: The present disclosure provides variant OmpG polypeptides, compositions comprising the OmpG variant polypeptides, and methods for using the variant OmpG polypeptides as nanopores for determining the sequence of single stranded nucleic acids. The variant OmpG nanopores reduce the ionic current noise versus the parental OmpG polypeptide from which they are derived and thereby enable sequencing of polynucleotides with single nucleotide resolution. The reduced ionic current noise also provides for the use of these OmpG nanopore variants in other single molecule sensing applications, e.g., protein sequencing.

Abstract: A method is provided for preparing nanopore sequencing complexes in membranes for sequencing of polymers, e.g., polynucleotides and polypeptides. The nanopore sequencing complex is formed by the sequential linking of an enzyme to a nanopore that is inserted in a membrane, and of a polymer to the enzyme. Alternatively, the nanopore sequencing complex is formed by linking a preformed enzyme-polymer complex to a nanopore that is inserted in a membrane. The enzyme polymer complex is interchangeable.

Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L1351 in the mature alpha-hemolysin amino acid sequence. The a-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.

Abstract: Described herein are nanopore protein conjugates that can be used in DNA sequencing reactions. The nanopore protein conjugates includes a nanopore protein monomer that is joined to a DNA binding domain. The nanopore protein monomer is available to oligomerize with other nanopore protein monomers, while the DNA binding domain is available to bind to a template DNA strand. In certain examples, the nanopore protein monomer is an alpha-hemolysin monomer or variant thereof and the DNA binding domain is an Sso7d protein or variant thereof, such as an Sso7d-like protein. Also provided are nanopore protein assemblies incorporating the nanopore protein conjugates, along with methods of using the nanopore protein assemblies in sequencing reactions.

Abstract: The present disclosure provides variant OmpG polypeptides, compositions comprising the OmpG variant polypeptides, and methods for using the variant OmpG polypeptides as nanopores for determining the sequence of single stranded nucleic acids. The variant OmpG nanopores reduce the ionic current noise versus the parental OmpG polypeptide from which they are derived and thereby enable sequencing of polynucleotides with single nucleotide resolution. The reduced ionic current noise also provides for the use of these OmpG nanopore variants in other single molecule sensing applications, e.g., protein sequencing.

Abstract: Described herein are variants of alpha-hemolysin having at least one amino acid substitution at H35G, E111N, M113A, and/or K147N in the mature, wild-type alpha-hemolysin amino acid sequence. In certain examples, the variant may have a substitution at E111S, M113S, T145S, K147S, or L135I in the mature alpha-hemolysin amino acid sequence. The ?-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having an increased nanopore lifetime. Further, provided are variants that, in addition to providing increased lifetime, provide a decreased time-to-thread. Hence, the variants provided herein both increase nanopore lifetime and improve efficiency and accuracy of DNA sequencing reactions using nanopores comprising the variants.