A highly constrained pseudo-tetrapeptide (OC252-324) further defines a new allosteric binding site located near the center of fructose-1,6-bisphosphatase. In a crystal structure, pairs of inhibitory molecules bind to opposite faces of the enzyme tetramer. Each ligand molecule is in contact with three of four subunits of the tetramer, hydrogen bonding with the side chain of Asp187 and the backbo...

GTP:GTP guanylyltransferase has been purified from the yolk platelets of Artemia cysts. The 480-kDa enzyme catalyzes the reversible reaction 2GTP<==>Gp4G + PPi and contains immunologically related polypeptides of 142, 88, and 45 kDa and a distinct 80-kDa component. The 88 and 45 kDa species can be covalently labeled with [alpha-32P]GTP. Even in crude extracts, the enzyme appears to be partially...

Memantine hydrochloride is a reversible cholinesterase inhibitor used in the treatment of Alzheimer’s disease, low-moderate affinity, uncompetitive n-methyl-d-aspartate (NMDA) receptor antagonist, with strong voltage dependency and rapid blocking/unblocking kineticsThe present study was explore potential mamentine loaded nanoparticle.with varying quantity chitosan byionotropic gelation method.T...

Inhibitors of COMT are clinically used for the treatment Parkinson’s disease. Here, we report first natural pentacyclic triterpenoid-type inhibitors and their structure-activity relationships inhibition mechanism. The most potent compounds were found to be oleanic acid, betulinic acid celastrol with IC50 values 3.89–5.07 μM, that acted as mixed (uncompetitive plus non-competitive) COMT, represe...

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that has no cure because its etiology still unknown, and main treatment the administration of acetylcholinesterase (AChE) inhibitors. The study mechanism action this family compounds critical for design new more potent specific In work, we molecular basis an uncompetitive inhibitor (compound 1, 2β, 3α-dihydroxy-5α-cholestan-6-...

In our previous study, we compared the two α-amylase enzymes from Bacillus sp.KR8104, BKA∆(N44) and BKA∆(N44C193) which is the secreted form of it. The results indicated that the presence of 193 amino acids propeptide in the C-terminal of BKA∆(N44) changed its enzymatic parameters like an uncompetitive inhibitor in comparison to BKA∆(N44C193). In the present study, we cloned the DNA sequence of...

Kinetic and thermodynamic studies were made on the effect of caffeine on the activity of adenosine deaminase in 50 mM sodium phosphate buffer, pH 7.5, using UV spectrophotometry and isothermal titration calorimetry (ITC). An uncompetitive inhibition was observed for caffeine. A graphical fitting method was used for determination of binding constant and enthalpy of inhibitor binding by using iso...

Examination of the effects of mononucleotides on Sma nuc endonuclease originated from Gram negative bacterium Serratia marcescens displayed that any mononucleotide produced by Sma nuc during hydrolysis of DNA or RNA may regulate the enzyme activity affecting the RNase activity without pronounced influence on the activity towards DNA. The type of carbohydrate residue in mononucleotides does not ...

Indomethacin inhibited rat liver glutathione S-transferases (EC 2.5.1.18). Its inhibition was non-competitive with respect to 3,4-dichloronitrobenzene with an apparent Ki of 5.3 X 10(-5) M and uncompetitive with respect to glutathione with an apparent Ki of 4.0 X 10(-5) M. 4-Chlorobenzoic acid and 5-methoxy-2-methylindole-3-acetic acid, two metabolites of indomethacin, were weak inhibitors of t...