Leucine aminopeptidase models

Thiourea probably acts in a manner comparable to that of Naddtc and should also be administered after cis-Pt treatment (78). Like Naddtc, thiourea is able to remove platinum from platinated enzymes, such as leucine aminopeptidase (76, 128), y-glutamyltranspeptidase (76,128), and fumarase (129) (Fig. 9), and from Pt-methionine model adducts (Table III) (131). However, thiourea appears to be less useful as an inhibitor of nephrotoxicity it also reacts quite rapidly with platinum-DNA cross-links (56). 

Found to be subject to metal ion catalysis, but the discovery by Kroll in 1952 that the hydrolysis af a-amino acid esters was catalyzed by metal ions stimulated considerable interest in the area. Many of these reactions can be considered as simple model systems for such metalloenzymes as arboxypeptidase A, leucine aminopeptidase and glycylglycine dipeptidase.25... 

Parellada, J., and M. Guinea. 1995. Flavonoid inhibitors of trypsin and leucine aminopeptidase A proposed mathematical model for IC50 estimation. J Nat Prod 58 823. 

A major part of the work on the structural requirements for binding of inhibitors to the active site of either aminopeptidase M or aminopeptidase Mil has been conducted using bestatin (see Figure 6.3A) as the model inhibitor and interpreted from the known structure-activity relationships of bestatin analogues towards leucine-aminopeptidase [43]. 

A hypothetical model of the binding of bestatin to leucine-aminopeptidase was first proposed by Nishizawa et al. [43] Figure 6.2B). Four functional groups present in bestatin are considered to be essential for efficient interaction with the active site of leucine-aminopeptidase the C-1 substituent, a free fV-terminal amino group, an alcohol group in the C-2 position and a free C-terminal carboxyl group. 

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