Method for preparing botulinum neurotoxin type A light chain
View Patent ↗The present invention provides a preparation of botulinum toxin light chain type A or E, wherein the preparation is both catalytically active and soluble. Preferably, the preparation consists essentially of amino acid residues 1 through 425 of the botulinum toxin light chain type A. A method of screening inhibitors is also provided, wherein the method comprises exposing a test inhibitor to the preparation of botulinum toxin light chain type A and evaluating the biological activity of the preparation. In another embodiment, a method of providing a catalytically active, soluble preparation of botulinum toxin light chain, type A is provided, wherein the method comprises obtaining an expression vector comprising a DNA sequence encoding amino acid residues 1-425 and expressing a polypeptide.
1. A preparation of botulinum toxin light chain consisting of amino acid residues selected from the group consisting of residues 1 through 424, 1 through 425 and 1 through 426 of botulinum toxin light chain type A (SEQ ID NO:14).
2. The preparation of claim 1 wherein the preparation has a solubility of at least 40 mg/L.
3. The preparation of claim 1 wherein the preparation remains soluble for at least two weeks at 4° C.
4. The preparation of claim 1 wherein the preparation is catalytically active.
5. The preparation of claim 1 wherein the preparation consists of amino acid residues 1 through 425 of the botulinum toxin light chain type A (SEQ ID NO:14).
6. A method of providing a catalytically active, soluble preparation of botulinum toxin light chain, type A, comprising:
(a) obtaining an expression vector comprising a DNA sequence encoding an amino acid sequence consisting of residues 1 through 425 of light chain type A (SEQ ID NO:14); and
(b) expressing a polypeptide.