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Papain‐Catalyzed Peptide Bond Formation: Enzyme‐Specific Activation with Guanidinophenyl Esters
Author(s) -
de Beer Roseri J. A. C.,
Zarzycka Barbara,
AmatdjaisGroenen Helene I. V.,
Jans Sander C. B.,
Nuijens Timo,
Quaedflieg Peter J. L. M.,
van Delft Floris L.,
Nabuurs Sander B.,
Rutjes Floris P. J. T.
Publication year - 2011
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.201100267
Subject(s) - papain , chemistry , peptide bond , peptide , catalysis , enzyme , enzyme catalysis , stereochemistry , combinatorial chemistry , biochemistry , organic chemistry
The substrate mimetics approach is a versatile method for small‐scale enzymatic peptide‐bond synthesis in aqueous systems. The protease‐recognized amino acid side chain is incorporated in an ester leaving group, the substrate mimetic. This shift of the specific moiety enables the acceptance of amino acids and peptide sequences that are normally not recognized by the enzyme. The guanidinophenyl group (OGp), a known substrate mimetic for the serine proteases trypsin and chymotrypsin, has now been applied for the first time in combination with papain, a cheap and commercially available cysteine protease. To provide insight in the binding mode of various Z‐X AA ‐OGp esters, computational docking studies were performed. The results strongly point at enzyme‐specific activation of the OGp esters in papain through a novel mode of action, rather than their functioning as mimetics. Furthermore, the scope of a model dipeptide synthesis was investigated with respect to both the amino acid donor and the nucleophile. Molecular dynamics simulations were carried out to prioritize 22 natural and unnatural amino acid donors for synthesis. Experimental results correlate well with the predicted ranking and show that nearly all amino acids are accepted by papain.