The mechanism of enzyme-inhibitor-substrate reactions has been analyzed from a theoretical standpoint and illustrated by data from the system cholinesterase-physostigmine-acetylcholine. This treatment is by no means limited to a single system but should be generally applicable to others of similar type. Competitive enzyme-inhibitor-substrate systems show the same characteristic "zones of behavi...

Tricarboxylic acids were shown to be both competitive and noncompetitive inhibitors of aconitase with the inhibition pattern dependent upon which substrate was used. Tricarballyate and fluorocitrate were linear competitive inhibitors when citrate or isocitrate was the substrate but noncompetitive inhibitors when cis-aconitate was the substrate. transAconitate was a linear competitive inhibitor ...

K+ is a competitive inhibitor of the uptake of the other alkali metal cations by yeast. Rb+ is a competitive inhibitor of K+ uptake, but Li+, Na+, and Cs+ act like H+. At relatively low concentrations they behave as apparent noncompetitive inhibitors of K+ transport, but the inhibition is incomplete. At higher concentrations they inhibit the remaining K+ transport competitively. Ca++ and Mg++ i...

N-acetyl-B-D-Glucosaminidase was purified by affinity and ionexchange chromatography. Two major, A and B, and three minor intermediate forms were isolated and characterized. NAG-A and NAG-B were purified 440 and 1200 fold with final yields of 16 and 23 percent respectively. Each activity was represented by a single protein band. After 70 min preincubation at 55°C a loss of70% activity of N...

We show that the 4-oxo analogue of N-acetyl-D-neuraminic acid strongly inhibits N-acetylneuraminate lyase (NeuAc aldolase, EC 4.1.3.3) from Clostridum perfringens (Ki = 0.025 mM) and Escherichia coli (Ki = 0.15 mM). In each case the inhibition was competitive. N-Acetyl-D-neuraminic acid; N-Acetylneuraminate lyase; N-Acetyl-D-neuraminic acid analog; 5-Acetamido-3,5-dideoxy-beta-D-manno-non-2,4-d...

objective(s):one strategy for the treatment of diabetes is inhibition of pancreatic α- amylase. plants contains different chemical constituents with potential for inhibition of α-amylase and hence maybe used as therapeutic. materials and methods: urtica dioica and juglans regia linn were tested for α-amylase inhibition. different concentrations of leaf aqueous extracts were incubated with enzym...

Objective(s):One strategy for the treatment of diabetes is inhibition of pancreatic α- amylase. Plants contains different chemical constituents with potential for inhibition of α-amylase and hence maybe used as therapeutic. Materials and Methods: Urtica dioica and Juglans regia Linn were tested for α-amylase inhibition. Different concentrations of leaf aqueous extracts were incubated with enzym...

In this study the effects of Fe2O3 and Fe3O4 magnetic nanoparticles and EDTA on urease activity was investigated. The effect of nano-Fe2O3 and nano-Fe3O4 on urease activity were investigated. Urease activity was studies by UV-Vis spectrophotometry at 40 °C at pH = 7.2 using sodium phosphate as buffer. Measurements were carried out using 0.075 mg/ml of urease and a range of nano-Fe2O3 and nano-F...

7-But-2-ynyl-9-(6-methoxy-pyridin-3-yl)-6-piperazin-1-yl-7,9-dihydro-purin-8-one (ER-319711) is a novel dipeptidyl peptidase (DPP)-IV inhibitor discovered in our laboratories. In this study, we have characterized this DPP-IV inhibitor in vitro and in vivo as an antidiabetic agent. The trifluoroacetate salt form of ER-319711, ER-319711-15, inhibited human DPP-IV with an IC(50) value of 0.089 mic...

Glutamate racemase (GR) catalyzes the cofactor independent stereoinversion of l- to d-glutamate for biosynthesis of bacterial cell walls. Because of its essential nature, this enzyme is under intense scrutiny as a drug target for the design of novel antimicrobial agents. However, the flexibility of the enzyme has made inhibitor design challenging. Previous steered molecular dynamics (MD), docki...