L-usnic acid inactivates urease by formation of high molecular weight aggregates which can reached by a maximum of 880 000. L-cysteine partially reverses the inactivation of stimulating the appearance of active high molecular weight polymers. The existence of two class of binding points for L-usnic acid on the urease molecule is proposed, the first showing high affinity for the ligand, related ...

Nevirapine (NVP) treatment is associated with a significant incidence of liver injury. We developed an anti-NVP antiserum to determine the presence and pattern of covalent binding of NVP to mouse, rat, and human hepatic tissues. Covalent binding to hepatic microsomes from male C57BL/6 mice and male Brown Norway rats was detected on Western blots; the major protein had a mass of ~55 kDa. Incubat...

this study describes the synthesis of molecularly imprinted polymers (mips) by using an anti-che ops, namely dursban, as a template. non-covalent bulk polymerization was successfully applied to synthesis different imprinted and non-imprinted polymers with maa, mma, aa, and 4-vpy as monomer in selected porogens (chloroform, toluene, and acetonitrile). in order to evaluate the template binding of...

A pH-variation study of jack bean (Canavalia ensiformis) urease steady-state kinetic parameters and of the inhibition constant of boric acid, a urease competitive inhibitor, was performed using both noninhibitory organic (MES, HEPES and CHES) and inhibitory inorganic (phosphate) buffers, in an effort to elucidate the functions exercised in the catalysis by the ionizable groups of the enzyme act...

In vivo urease metallocenter assembly in Klebsiella aerogenes requires the presence of several accessory proteins (UreD, UreF, and UreG) and is further facilitated by UreE. In this study, UreG was isolated and shown to be a monomer with an Mr of 21,814 +/- 20 based on gel filtration chromatography and mass spectrometric results. Although it contains a P-loop motif typically found in nucleotide-...

Proteases are important enzymes that their role in various industries is undeniable. However, keeping enzymes stable during its activity in harsh conditions is so important. In this study, protease enzyme was immobilized on the porous silica particles and its stability in different temperatures and pHs was evaluated. First silica particles were aminated by 3-aminopropyltriethoxysilane then the ...

In this review, we present a summary of how computer modeling has been used in the development of covalent-modifier drugs. Covalent-modifier drugs bind by forming a chemical bond with their target. This covalent binding can improve the selectivity of the drug for a target with complementary reactivity and result in increased binding affinities due to the strength of the covalent bond formed. In...