D-aminopeptidase

Asano, Y. and Yamaguchi, S. (2005) Dynamic kinetic resolution of amino acid amide catalyzed by D-aminopeptidase and a-amino-e-caprolactam racemase. Journal of the American Chemical Society, 127 (21), 7696-7697. 

L-Alanine amide (S)-8 was converted to D-alanine (R)-9 in excellent yield and enantiomeric excess by incubation of the substrate with a-amino-e-caprolactam racemase from Achromohacter obae and D-aminopeptidase from Ochrobactrum anthropi (Scheme 2.5) [7]. 

Sugie and Suzuki11671 demonstrated the occurrence of D-aminoacylase, which specifically hydrolyzes the amide bond of N-acyl-D-amino acids, in actinomycetes, and applied the enzyme to the production of D-phenylglycine. Recently, a new d-aminopeptidase was found in Alcaligenes denitrijicans, and shown to act on various N-acyl-D-amino acids including N-acetyl-D-methionine[168, 1691. 

Production of optically pure amino acids using their amides as racemic precursors and L-aminopeptidases as catalysts is a well-established commercial process. To overcome the limit of 50% conversion, D-aminopeptidases and amino acid amide racemases were also developed [182]. 

Phe, D-Phe and D-Phe ierf-butyl ester. The enzyme was not active toward L-Phe methyl ester, (L-Phe)2 methyl ester, (L-Phe)4, Boc-(L-Phe)4, Boc-(L-Phe)4 methyl ester, (D-VaDa, (D-Leu)2, or (D-Ala)n (n = 2 - 5). These properties indicated that the enzyme is an endopeptidase that acts D-stereospecifically upon peptides composed of aromatic D-amino acids. On the other hand, a dimer was formed when D-Phe methyl ester and D-Phe amide were the substrates. Eight stereoisomers of Phe trimer were synthesized, and their effectiveness as substrates for the enzyme was tested. The enzyme recognized the configuration of the second D-Phe of tripeptides and catalyzed the hydrolysis of the second peptide bond from the N-terminus. The calculated Vmax/Km values for the peptides containing L-Phe were lower than that for (D-Phels, affected by the configuration of the neighboring L-Phe. The enzyme also showed P-lactamase activity toward ampicillin and penicillin G. The calculated Vmax values of the enzyme for b-lactam compounds were about the same as those for (D-Phe)3 and (D-Phe)4, while the Km values were several hundred times larger. On the other hand, carboxypeptidase DD and D-aminopeptidase activities were undetectable. 

Cole [6]. The N2 fragment is known to contain the cAMP-dependent phosphorylation site, serine residue 38 [7]. We confirmed this with cAMP dependency phosphoiylated and subsequently N-bromosuccinimide-treated histone HI. The [ P]ADP-ribosylated N2 fragment was further treated with three peptidases in the order of cathepsin D, aminopeptidase M, and carboxypeptidase B, and the product was analyzed by high performance liquid chromatography. The radioactive product was identified as ADP-ribose-arginine adduct [8]. 

Discovery of D-Aminopeptidase, D-Amino Acid Amidase, and Alkaline o-Peptidase... 

D-Aminopeptidase (DAP) Ochrobactrum anthropi Cl-38 Ser Dynamic kinetic resolution, peptide bond formation... 

Asano, Y. and Yamaguchi, K., "Mutants of D-aminopeptidase with increased thermal stability." ]. Ferment. Bioeng., 79, 614-616 (1995). 

---