Glycoside hydrolases of families 32 (GH32) and 68 (GH68) belong to clan GH-J, containing hydrolytic enzymes (sucrose/fructans as donor substrates) and fructosyltransferases (sucrose/fructans as donor and acceptor substrates). In GH32 members, some of the sugar substrates can also function as inhibitors, this regulatory aspect further adding to the complexity in enzyme functionalities within thi...

Establishing the protein posttranslational modification (PTM) landscape at proteome scale relies on target specificity of relevant enzyme catalysts. Su et al. [ ACS Catal. 2021, 11, 14877] proposed that “the kcat/Km value is not best parameter to determine in vivo substrate an enzyme. Instead, binding affinities substrates are more important for determining enzymes a physiological setting”. The...

Catalytic particles are spatially organized in a number of biological systems across different length scales, from enzyme complexes to metabolically coupled cells. Despite operating on these all feature localized reactions involving partially hindered diffusive transport, which is determined by the collective arrangement catalysts. Yet it remains largely unexplored how arrangements affect inter...

Candida antarctica Lipase B (CALB) was covalently immobilized onto epoxy-activated macroporous poly(methyl methacrylate) Amberzyme beads (235 microm particle size, 220 A pore size) and nanoparticles (nanoPSG, diameter 68 nm) with a poly(glycidyl methacrylate) outer region. Amberzyme beads allowed CALB loading up to 0.16 g of enzyme per gram of support. IR microspectroscopy generated images of A...

Addition of thioglycolate and DEAE-Sephadex chromatography were used to analyze the cleavage of the C(3')-O-P bond 3' to AP (apurinic/apyrimidinic) sites in DNA and to distinguish between a mechanism of hydrolysis (which would allow the nicking enzyme to be called 3' AP endonuclease) or beta-elimination (so that the nicking enzyme should be called AP lyase). For this purpose, DNA labelled in th...

In vitro studies with human liver indicate that the major catalyst involved in the bioactivation of the hepato-carcinogen aflatoxin B1 (AFB1) to its genotoxic 2,3-epoxide derivative is cytochrome P-450NF (P-450NF), a previously characterized protein that also catalyzes the oxidation of nifedipine and other dihydropyridines, quinidine, macrolide antibiotics, various steroids, and other compounds...

In animal behavioral biology, there are several cases in which an autonomous observing/training system would be useful. 1) Observation of certain species continuously, or for documenting specific events, which happen irregularly; 2) Longterm intensive training of animals in preparation for behavioral experiments; and 3) Training and testing of animals without human interference, to eliminate po...

Lignin peroxidase (LiP) is an important enzyme for degrading aromatic hydrocarbons not only in nature but also in industry. In the presence of H₂O₂, this enzyme can easily decompose lignin and analogue compounds under mild conditions. In this reaction mechanism, LiP catalyzes the C-C cleavage of a propenyl side chain, being able to produce veratraldehyde (VAD) from 1-(3',4'-dimethoxyphenyl) pro...

The dTDP-glucose 4,6-dehydratase catalyzed conversion of dTDP-glucose to dTDP-4-keto-6-deoxyglucose occurs in three sequential chemical steps: dehydrogenation, dehydration, and rereduction. The enzyme contains the tightly bound coenzyme NAD(+), which mediates the dehydrogenation and rereduction steps of the reaction mechanism. In this study, we have determined that Asp135 and Glu136 are the aci...