Domain mapping of a claudin-4 modulator, the C-terminal region of C-terminal fragment of Clostridium perfringens enterotoxin, by site-directed mutagenesis

Molecular Determinants of the Interaction between Clostridium perfringens Enterotoxin Fragments and Claudin-3

“…In CPE, Tyr 306 , Tyr 310 , Tyr 312 , and Leu 315 have been shown to be involved in the CPE-Cld4 interaction (36,37). Similarly, we found that deletion of amino acids 310 -319 diminished binding of Cld3 and Cld4 to GST-CPE (supplemental Fig.…”

“…CPE (36) and formation of an aromatic core within an ECL2-dimer is involved in the transinteraction of claudins between two opposing cells (21). Others have speculated that aromatic residues in claudin could also interact with the aromatic residues in CPE (38).…”

Structural Constraints for the Binding of Short Peptides to Claudin-4 Revealed by Surface Plasmon Resonance

“…This pattern constituted an apparent Ecl2 binding motif; we propose that the first Tyr or Trp is the priming or docking site and the remaining Tyr and Leu/Ile residues participate in the chemical bonding of the contact. Reports demonstrated the importance of the three Tyr in C-Cpe (11), and a recent study indicated that the leucine is also critical for the binding (12), but no study has been done directly with a peptide as short as 12 amino acids, even with the last 4 amino acids of Cpe30 eliminated.…”

“…The structure of C-Cpe (amino acids 194 -319) (10) reveals that two ␤-strands and an intervening large surface loop provide the structure that binds Cldn-4, with the three tyrosine residues (Tyr-306, Tyr-310, and Tyr-316) in this loop providing important contacts (11). An alanine scan also identified Tyr-306 and Leu-315 as indispensable for Cldn-4 binding and modulation of TJ function (12). The affinity of C-Cpe binding to Cldn-4 has been measured at micro-to subnanomolar levels by various approaches (2,4).…”

Recent Advances in Claudin-Targeting Technology

“…We used deletion analysis and alaninescanning to map the functional domains of c-cPE. 37,38) We then prepared a phage library that contained phages displaying various c-cPE peptides in which individual functional amino acids had been randomly mutated to any of the 20 amino acids. 39) a novel type of protein expression system using budded Mice were nasally immunized with vehicle, oVa, a mixture of oVa and c-cPE, oVa-c-cPE, or oVa-c-cPE303 (all doses equivalent to 5 µg oVa) once weekly for 3 weeks.…”