17263-44-4Relevant articles and documents
Enzymatic C-terminal amidation of amino acids and peptides
Nuijens, Timo,Piva, Elena,Kruijtzer, John A.W.,Rijkers, Dirk T.S.,Liskamp, Rob M.J.,Quaedflieg, Peter J.L.M.
experimental part, p. 3777 - 3779 (2012/09/22)
Herein, we describe two versatile and high yielding enzymatic approaches for the conversion of semi-protected amino acid and peptidyl C-terminal α-carboxylic acids into their corresponding amides. In the first approach, the lipase Candida antarctica lipase-B (Cal-B), and in the second approach, the protease Subtilisin A, are used, respectively. We found that by using the ammonium salt of the α-carboxylic acid instead of separate ammonia sources, the enzymatic amidation reactions proceeded much faster without side reactions and gave near to quantitative yields of products.
Papain-catalyzed peptide bond formation: Enzyme-specific activation with guanidinophenyl esters
de Beer, Roseri J.A.C.,Zarzycka, Barbara,Amatdjais-Groenen, 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.
experimental part, p. 2201 - 2207 (2012/05/05)
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-XAA-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.
C-terminal peptide amidation catalyzed by orange flavedo peptide amidase
Cerovsky, Vaclav,Kula, Maria-Regina
, p. 1885 - 1887 (2007/10/03)
The reverse reaction of amide hydrolysis can be achieved with the peptide amidase derived from oranges [Eq(1); Z=benzyloxycarbonyl]. The C-terminal carboxy group of the peptide is directly converted into an amide group by condensation with an ammonium salt. The amidation of peptides is of major interest since the biological activity of proteohormones and peptides is strongly influenced by the presence of a C-terminal amide group.
