APOBEC3G catalyzes deamination of cytosines in HIV-1 genome, and restricts the HIV-1 infection. Here, we propose a picomole-scale assay for the detection of DNA deamination catalyzed by APOBEC3G. Our results show the suitability of the developed method for a time course analysis of enzyme-catalyzed DNA modifications.

Enzyme-substrate binding constants, K’e, for chymotrypsin and specific amide (N-acetyl-Mryptophanamide and Nacetyl-L-phenylalaninamide) and ester (N-acetyl-L-tryptophan ethyl ester) substrates have been measured by a proflavin-displacement method. Also, the rate constant for the formation of one intermediate in the chymotrypsincatalyzed hydrolysis of the ester has been determined at selected pH...

During the course of the transformation of 1,3-dichloro-2-propanol (DCP) into (R)-3-chloro-1,2-propanediol [(R)-MCP] with the cell extract of Corynebacterium sp. strain N-1074, epichlorohydrin (ECH) was transiently formed. The cell extract was fractionated into two DCP-dechlorinating activities (fractions Ia and Ib) and two ECH-hydrolyzing activities (fractions IIa and IIb) by TSKgel DEAE-5PW c...

An efficient one-pot method for the enzyme- and ruthenium-catalyzed enantioselective transformation of α-allenic alcohols into 2,3-dihydrofurans has been developed. The method involves an enzymatic kinetic resolution and a subsequent ruthenium-catalyzed cycloisomerization, which provides 2,3-dihydrofurans with excellent enantioselectivity (up to >99 % ee). A ruthenium carbene species was propos...

This paper describes a microanalytical method for determining enzyme kinetics using a continuous-flow microfluidic system. The analysis is carried out by immobilizing the enzyme on microbeads, packing the microbeads into a chip-based microreactor (volume approximately 1.0 nL), and flowing the substrate over the packed bed. Data were analyzed using the Lilly-Hornby equation and compared to value...

To elucidate the mechanism underlying reduction of nitroglycerin (GTN) to nitric oxide (NO) by mitochondrial aldehyde dehydrogenase (ALDH2), we generated mutants of the enzyme lacking the cysteines adjacent to reactive Cys302 (C301S and C303S), the glutamate that participates as a general base in aldehyde oxidation (E268Q) or combinations of these residues. The mutants were characterized regard...

Fluorine is commonly applied in pharmaceuticals to block the degradation of bioactive compounds at a specific site of the molecule. Blocking of the reaction center of the enzyme-catalyzed ring closure of 1,2,3,4-tetrahydrobenzylisoquinolines by a fluoro moiety allowed redirecting the berberine bridge enzyme (BBE)-catalyzed transformation of these compounds to give the formation of an alternativ...

Anisic acid (p-methoxybenzoic acid) was characterized as a tyrosinase inhibitor from ani-seed, a common food spice. It inhibited the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) catalyzed by tyrosinase with an IC50 of 0.60 mM. The inhibition of tyrosinase by anisic acid is a reversible reaction with residual enzyme activity. This phenolic acid was found to be a classical noncompetitive in...

Putrescine can be converted to y-aminobutyraldehyde by enzymes from different sources (l-3). It. is generally believed that this conversion is catalyzed by a nonspecific diamine oxidase. The presence of such an enzyme in bacteria, however, has not been firmly established experimentally. We have previously reported that, in a mutant of Escherichia co& B selected to grow on putrescine as the sole...

A soluble pyridine nucleotidase was first described in bull semen by Leone and Bonaduce (1). During studies on the specificity of this enzyme, we observed that passage of dilute semen through a column composed of calcium phosphate gel and diethylaminoethyl cellulose anion exchanger (Whatman)] resulted in a preparation of high specific activity. In this single purification step the specific acti...