167693-86-9Relevant articles and documents
Aziridine analogs of [[trans-(epoxysuccinyl)-L-leucyl]amino]-4- guanidinobutane (E-64) as inhibitors of cysteine proteases
Martichonok,Plouffe,Storer,Menard,Jones
, p. 3078 - 3085 (1995)
Aziridine derivatives of E-64 have been synthesized, and their characterization against the cysteine proteases cathepsin B, cathepsin L, and papain is reported. The inhibition was found to be strongly pH-dependent, with maximum activity observed at pH 4, indicating that the protonated aziridinium ion form of the inhibitor is the more reactive form. At low pH, the peptide aziridine HO-(L)Az-Leu-NH-iAm inactivated papain with a second- order rate constant, k(inac)/K(j), of 7.0 x 104 M-1 s-1, a value very close to that observed with E-64 or with the corresponding epoxysuccinyl analog HO-(L)Eps-Leu-NH-iAm. This demonstrates that with the correct peptide sequence, aziridine analogs of E-64 can be good irreversible inhibitors of cysteine proteases. Substitution of the epoxysuccinyl moiety by an aziridine does not affect the specificity of inhibition against the three proteases used in this study. The D-diastereomer is the preferred (by 10-fold) diastereomer for the inhibition of cysteine proteases. The reactivity of both diastereomers of iBuNH-Az-LeuPro-OH against cathepsin B was also found to be much lower than that of iBuNH-(L)Eps-LeuPro-OH, which is a potent selective inhibitor of cathepsin B. These differences are attributed mainly to the presence of the protonated aziridine ring, which can modify the binding mode of aziridine analogs at the active site of cysteine proteases.
Additivity or cooperativity: Which model can predict the influence of simultaneous incorporation of two or more functionalities in a ligand molecule?
Nasief, Nader N.,Hangauer, David
, p. 897 - 915 (2015/05/27)
Predicting how binding affinity responds to ligand structural modifications in structure-activity relationship studies (SAR) is a major challenge in medicinal chemistry. This is particularly true when two or more of these modifications are carried out simultaneously. In this study, we present binding affinity data from several series of thermolysin inhibitors in which simultaneous structural modifications were investigated to determine whether they are cooperative or additive. Data revealed that, while additivity is at work in some cases, cooperativity is more commonly demonstrated. Cooperativity and additivity were then correlated with ligand descriptors, such as the spacing and the topological features of the modified groups, in a manner that may provide guidance as to when each model should be utilized. Cooperativity was particularly associated with contiguous groups and small unbranched hydrophobic side chain. Additivity, on the other hand, was associated with moderately distant hydrophobic group combinations and side chain branching. Such correlations can improve the predictability of SAR studies and can provide a starting point for additional investigations that may lead to further significant enhancements in the current scoring functions.
Influence of neighboring groups on the thermodynamics of hydrophobic binding: An added complex facet to the hydrophobic effect
Nasief, Nader N.,Hangauer, David
supporting information, p. 2315 - 2333 (2014/04/17)
The thermodynamic consequences of systematic modifications in a ligand side chain that binds in a shallow hydrophobic pocket, in the presence and absence of a neighboring ligand carboxylate group, were evaluated using isothermal titration calorimetry (ITC
Mechanistic studies on the inactivation of papain by epoxysuccinyl inhibitors
Meara, Joseph P.,Rich, Daniel H.
, p. 3357 - 3366 (2007/10/03)
Analogs of the epoxysuccinyl peptide cysteine proteinase inhibitor, EP- 475 (2a), in which the free carboxylate has been replaced by hydroxamic acid, amide, methyl ketone, hydroxyl, and ethyl ester functionalities, have been synthesized. Individual rate c
