Expression, purification, and characterization of anuran saxiphilins using thermofluor, fluorescence polarization, and isothermal titration calorimetry

STAR Protoc. 2024 Mar 15;5(1):102792. doi: 10.1016/j.xpro.2023.102792. Epub 2023 Dec 20.

Abstract

Anuran saxiphilins (Sxphs) are "toxin sponge" proteins thought to prevent the lethal effects of small-molecule neurotoxins through sequestration. Here, we present a protocol for the expression, purification, and characterization of Sxphs. We describe steps for using thermofluor, fluorescence polarization, and isothermal titration calorimetry assays that probe Sxph:saxitoxin interactions using a range of sample quantities. These assays are generalizable and can be used for other paralytic shellfish poisoning toxin-binding proteins. For complete details on the use and execution of this protocol, please refer to Chen et al. (2022).1.

Keywords: Protein Biochemistry; Protein expression and purification; Structural Biology.

MeSH terms

  • Calorimetry
  • Fluorescence Polarization
  • Neurotoxins*
  • Saxitoxin* / metabolism

Substances

  • Saxitoxin
  • Neurotoxins