The cysG gene of Salmonella typhimurium is involved in synthesis of both cobalamin (B12) and siroheme (a cofactor required for SO3(2-) and NO2(2-) reductases). The failure to reduce SO3(2-) leads to cysteine auxotrophy, for which the enzyme is named. Although Escherichia coli does not synthesize B12 de novo, it possesses a very similar CysG enzyme which has been shown to catalyze two methylatio...

Zipper-interacting protein kinase (ZIPK) is a widely expressed serine/threonine kinase implicated in cell death and smooth muscle contractility, but its mechanism of regulation is unknown. We have identified six phosphorylation sites in ZIPK that regulate both its enzyme activity and localization, including Thr180, Thr225, Thr265, Thr299, Thr306, and Ser311. Mutational analysis showed that phos...

1. Cellulases and xylanases display a modular architecture that comprises a catalytic module linked to one or more non-catalytic carbohydrate-binding modules (CBMs). CBMs have been classified into 52 different families, based on primary structure similarity. These non-catalytic modules mediate a prolonged and intimate contact of the enzyme with the target substrate eliciting efficient hydrolysi...

Various perennial C4 grass species have tremendous potential for use as lignocellulosic biofuel feedstocks. Currently available grasses require costly pre-treatment and exogenous hydrolytic enzyme application to break down complex cell wall polymers into sugars that can then be fermented into ethanol. It has long been hypothesized that engineered feedstock production of cell wall degrading (CWD...

Tyrosine hydroxylase activity of synaptosomes isolated from rat brain was examined. A modified tritium-displacement assay was used, which allowed the measurement of tyrosine hydroxylase activity without the addition of either inhibitors of the metabolism of the hydroxylated products or added exogenous cofactor. The enzyme activity was strongly inhibited by the addition of exogenous catecholamin...

A study was conducted to assess the effect of feed form and microbial enzyme supplementation on performance, endogenous activities nutrient digestibility in broiler chickens fed Tanzania-type diets. total 480 day-old Ross 308 were allocated a 2 (mash or pellet) × 4 (no enzyme, Axtra XB, Quantum Blue XB + Blue) factorial arrangement, completely randomized design with 10 birds per replicate. Feed...

The selective activation of prodrug(s) in tumor tissues by exogenous enzyme(s) for cancer therapy can be accomplished by several ways, including gene-directed enzyme prodrug therapy (GDEPT), virus-directed enzyme prodrug therapy (VDEPT), and antibody-directed enzyme prodrug therapy (ADEPT). The central part of enzyme/prodrug cancer therapy is to deliver drug-activating enzyme gene or functional...

Abstract: In order that the nth-order Generalized Frequency Response Function (GFRF) for nonlinear systems described by a NARX model can be directly written into a more straightforward and meaningful form in terms of the first order GFRF and model parameters, the nth-order GFRF is now determined by a new mapping function based on a parametric characteristic. This can explicitly unveil the linea...

In practice, it is usually difficult to obtain the physical model of nonlinear, rotor-bearing systems due to uncertain nonlinearities. In order to solve this issue to conduct the analysis and design of nonlinear, rotor-bearing systems, in this study, a data driven NARX (Nonlinear Auto-Regressive with exogenous inputs) model is identified. Due to the lack of the random input signal which is requ...