Identification and characterization of 3-substituted pyrazolyl esters as alternate substrates for cathepsin B: The confounding effects of DTT and cysteine in biological assays
作者:Michael C. Myers、Andrew D. Napper、Nuzhat Motlekar、Parag P. Shah、Chun-Hao Chiu、Mary Pat Beavers、Scott L. Diamond、Donna M. Huryn、Amos B. Smith
DOI:10.1016/j.bmcl.2007.06.091
日期:2007.9
Substituted pyrazole esters were identified as hits in a high hroughput screen (HTS) of the NIH Molecular Libraries Small Molecule Repository (MLSMR) to identify inhibitors of the enzyme cathepsin B. Members of this class, along with functional group analogs, were synthesized in an effort to define the structural requirements for activity. Analog characterization was hampered by the need to include a reducing agent such as dithiothreitol (DTT) or cysteine in the assay, highlighting the caution required in interpreting biological data gathered in the presence of such nucleophiles. Despite the confounding effects of DTT and cysteine, our studies demonstrate that the pyrazole I acts as alternate substrate for cathepsin B, rather than as an inhibitor. (c) 2007 Elsevier Ltd. All rights reserved.
5-Amino-1-phenylsulfonyl-4-pyrazolin-3-one
作者:G. E. H. Elgemeie、N. Hanfy、H. Hopf、P. G. Jones
DOI:10.1107/s0108270197012420
日期:1998.1.15
The title compound, C9H9N3O3S, crystallizes with two independent molecules in P2(1), although the symmetry is close to P2(1)/c. The keto tautomer is the only solid-state form. The main difference between the two molecules is the orientation of the phenyl rings. The five-membered rings are planar. An extensive hydrogen-bonding system connects the molecules into layers parallel to the xy plane.