Loading
PDBj
✖
MenuPDBj@FacebookPDBj@X(formerly Twitter)PDBj@BlueSkyPDBj@YouTubewwPDB FoundationwwPDBDonate
RCSB PDBPDBeBMRBAdv. SearchSearch help

45CM

F1, a fluorinated amino acid-containing CI2 variant, bound to alpha-chymotrypsin

This is a non-PDB format compatible entry.
Summary for 45CM
Entry DOI10.2210/pdb45cm/pdb
DescriptorChymotrypsinogen A, Chymotrypsin A chain B, F1, ... (7 entities in total)
Functional Keywordsprotease, inhibitor, complex, fluorinated amino acid, hydrolase
Biological sourceBos taurus (domestic cattle)
More
Total number of polymer chains4
Total formula weight33241.54
Authors
Sengoku, T.,Beattie, A.,Suga, H. (deposition date: 2026-08-24, release date: 2026-10-28)
Primary citationBeattie, A.,Vinogradov, A.,Okada, C.,Sengoku, T.,Katoh, T.,Suga, H.
In Vitro Selection of Functional Neoproteins Containing Highly Fluorinated Cores.
Angew.Chem.Int.Ed.Engl., :e5293145-e5293145, 2026
Cited by
PubMed Abstract: The inclusion of non-proteinogenic amino acids (npAAs) into proteins vastly expands their chemical repertoire and hence possible functional diversity. However, it remains challenging to obtain non-proteinogenic sequences that carry out a specific task. Here we develop a platform to discover functional non-standard proteins and illustrate its utility by generating a family of bioactive proteins whose hydrophobic cores are built using fluorinated amino acids (fAAs). Starting from the protein chymotrypsin inhibitor 2 (CI2), we use genetic code reprogramming, combinatorial mutagenesis and mRNA display-based in vitro selection to discover fluorinated mutant sequences with optimised inhibitory activity. Using microwave-assisted solid-phase peptide synthesis, we perform preparative chemical synthesis of 14 selected proteins, which contain up to eight fAAs-or 19 fluorine atoms. All are nanomolar inhibitors of chymotrypsin; several hits are more active than the wildtype, and possess thermostabilities of up to 70°C. Crystal structures reveal that these proteins maintain native-like folds, with fluorine atoms forming close and epistatically coupled packing contacts within the core. This work demonstrates how to generate functional protein sequences with multiple interacting npAAs, namely neoproteins, and thereby provides a framework for exploring the use of unnatural building blocks in protein design.
PubMed: 42745166
DOI: 10.1002/anie.5293145
PDB entries with the same primary citation
Experimental method
X-RAY DIFFRACTION (1.39 Å)
Structure validation

261584

PDB entries from 2026-10-28

PDB statisticsPDBj update infoContact PDBjnumon