8U5F

Crystal Structure of Trypsinized Clostridium perfringens Enterotoxin

Summary for 8U5F

• Entry DOI: 10.2210/pdb8u5f/pdb
• Descriptor: Heat-labile enterotoxin B chain, PHOSPHATE ION, GLYCEROL, ... (5 entities in total)
• Functional Keywords: heat-labile enterotoxin, toxin
• Biological source: Clostridium perfringens
• Total number of polymer chains: 8
• Total formula weight: 315901.34

Authors

Kapoor, S.,Ogbu, C.P.,Vecchio, A.J. (deposition date: 2023-09-12, release date: 2023-09-27, Last modification date: 2023-12-20)

Primary citation

Ogbu, C.P.,Kapoor, S.,Vecchio, A.J.
Structural Basis of Clostridium perfringens Enterotoxin Activation and Oligomerization by Trypsin.
Toxins, 15:-, 2023

PubMed Abstract: Clostridium perfringens enterotoxin (CpE) is a β-pore forming toxin that disrupts gastrointestinal homeostasis in mammals by binding membrane protein receptors called claudins. Although structures of CpE fragments bound to claudins have been determined, the mechanisms that trigger CpE activation and oligomerization that lead to the formation of cytotoxic β-pores remain undetermined. Proteolysis of CpE in the gut by trypsin has been shown to play a role in this and subsequent cytotoxicity processes. Here, we report solution structures of full-length and trypsinized CpE using small-angle X-ray scattering (SAXS) and crystal structures of trypsinized CpE and its C-terminal claudin-binding domain (cCpE) using X-ray crystallography. Mass spectrometry and SAXS uncover that removal of the CpE N-terminus by trypsin alters the CpE structure to expose areas that are normally unexposed. Crystal structures of trypsinized CpE and cCpE reveal unique dimer interfaces that could serve as oligomerization sites. Moreover, comparisons of these structures to existing ones predict the functional implications of oligomerization in the contexts of cell receptor binding and β-pore formation. This study sheds light on trypsin's role in altering CpE structure to activate its function via inducing oligomerization on its path toward cytotoxic β-pore formation. Its findings can incite new approaches to inhibit CpE-based cytotoxicity with oligomer-disrupting therapeutics.

PubMed: 37999500
DOI: 10.3390/toxins15110637

Experimental method

X-RAY DIFFRACTION (2.32 Å)