Structure and Mechanism of Bovine Lens Leucine Aminopeptidase

Mechanistic role of each metal ion in Streptomyces dinuclear aminopeptidase: Peptide hydrolysis and 7×1010-fold rate enhancement of phosphodiester hydrolysis

“…Dinuclear hydrolases such as APs have been investigated by numerous methods to reveal the reaction mechanisms [6,45,62,63], e.g., the role of metal ions in activity [19,31,64], and stabilization of the tetrahedral TS à , and binding of TS à -inhibitors [3,65]. Although a phospho-center has been known to serve as a TS à analogue of peptide substrates, the phosphodiester BNPP and the phosphonate ester p-nitrophenylphenylphosphonate can be effectively hydrolyzed by SgAP and its metal derivatives with a catalytic proficiency of $40 billion-fold for the native enzyme and 67 billion-fold for the di-Co 2+ derivative toward BNPP hydrolysis under physiological conditions [9,10].…”

A comparative study of proteolysis methods for the measurement of 3-nitrotyrosine residues: Enzymatic digestion versus hydrochloric acid-mediated hydrolysis

“…The digestion encompassed a first incubation in the presence of pepsin to cleave BSA at the C-terminus of the residues tyrosine, phenylalanine, tryptophan and leucine [33]. A subsequent treatment with pronase E was aimed at generating unspecific cleavages prior to incubation with aminopeptidase and prolidase simultaneously to form short peptides [34] and cleave proline-containing loops [35]. Finally, another treatment with pronase E was applied to further digest the remaining peptides and ensure a cleavage as complete as possible.…”

Purification, biochemical characterisation, and mass spectrometry analysis of phenylalanine aminopeptidase from the shoots of pea plants

“…The peptides derived from Phe-AP cover 40.2% of the AtLAP1 sequence. Based on the crystal structures of bovine and E. coli LAP, the residues of multimeric LAP with proposed roles in catalysis and coordinating zinc ions have been identified and appeared to be conserved in animals, plants, and bacteria (Gu and Walling 2002;Kim and Lipscomb 1994;Tu et al 2003). Four of the 5 zinc-binding residues (Lys 288, Asp 313, Asp 373, and Glu 375 in AtLAP1), one of the 2 residues involved in catalysis (Arg 377 in AtLAP1), and 8 of the 28 residues characteristic of LAP-N polypeptides (Tu et al 2003) were also observed in the sequences to which the Phe-AP peptides were assigned (Fig.…”