acetylcholinesterase (ache) is the main enzyme for the breakdown of acetylcholine. nowadays, usage of the inhibitors of this enzyme is one of the most important types of treatment of mild to moderate neurodegenerative diseases such as alzheimer’s disease. herbal medicines can be a new source of inhibitors of this enzyme. in this study we examined around 100 different plants to evaluate their in...

The C(2) proton resonances of the active site histidines (His 12 and His 119) of ribonuclease A have been exploited to study the inhibition pattern of both noncompetitive (four green tea polyphenols and their copper complexes) and competitive (3'-O-carboxy esters of thymidine and 3'-amino derivatives of uridine) inhibitors. Competitive inhibitors devoid of any phosphate group have the ability t...

SU9516 is a 3-substituted indolinone compound with demonstrated potent and selective inhibition toward cyclin dependent kinases (cdks). Here, we describe the kinetic characterization of this inhibition with respect to cdk2, 1, and 4, along with the crystal structure in complex with cdk2. The molecule is competitive with respect to ATP for cdk2/cyclin A, with a K(i) value of 0.031 microM. Simila...

Phosphate shows a non-competitive inhibition toward a Streptomyces aminopeptidase (sAP) between pH 5.85 (Ki = 0.48 mM) and 9.0 (110 mM), with a pKa of 7.1 likely due to ionization of H2PO4-. This non-competitive inhibition pattern indicates that phosphate binding to sAP in solution is different from that in the crystal structure, where phosphate is bound to the active site Zn(II) ions. Fluoride...

Competitive glycosidase inhibitors are generally sugar mimics that are costly and tedious to obtain because they require challenging and elongated chemical synthesis, which must be stereo- and regiocontrolled. Here, we show that readily accessible achiral (E)-1-phenyl-3-(4-strylphenyl)ureas are potent competitive α-glucosidase inhibitors. A systematic synthesis study shows that the 1-phenyl moi...

A chlorosis-inducing toxin of Pseudomonas phaseolicola was examined for inhibition of ornithine carbamoyltransferease prepared from acetone powder of bean (Phaseolus vulgaris L.) plants. The enzyme has a pH optimum at 8.5, involves a ternary complex reaction mechanism, and shows Michaelis constants of 5.0 mm and 1.7 mm for ornithine and carbamoylphosphate, respectively. Assuming reversible cata...

BACKGROUND Humans can be frequently exposed to Bisphenol A (BPA) via multiple sources, and babies are considered to be the most sensitive group to exposure of BPA. AIMS To investigate the inhibition potential of BPA towards human liver microsomes (HLMs)-catalyzed zidovudine (AZT) glucuronidation. MATERIALS AND METHODS In vitro HLMs incubation system was used to investigate the inhibition po...

We have measured the number of fluoride ions bound to one molecule of succinate dehydrogenase (SDH) of submitochondrial particles from porcine kidney cortex. Enzyme activity was studied according to the method of Dixon and the number of fluoride ions bound was established arithmetically. A mixed competitive and noncompetitive inhibition of SDH by fluoride was confirmed. At high levels of succin...