The preceding paper (2) describes experiments on the synthesis of glutamine in pigeon liver dispersions, which, together with the results of Krebs and his collaborators (3, 4) and of Bujard and Leuthardt (5), suggested that adenosine triphosphate may play an essential r81e in amide formation. Proof for this function of adenosine triphosphate has been obt.ained in studies with tissue extracts, w...

LIGAND Chemical Database for Enzyme Reactions was originally designed to link structural aspects of enzymatic proteins to chemical aspects of enzymatic reactions . It has accumulated all known enzymes classi ed according to the EC numbers given by the International Union of Biochemistry and Molecular Biology (IUBMB) and has been integrated within the DBGET/LinkDB system with protein structure d...

Changes in chicken embryo thymus after partial decerebration (including the hypophysis) and hypophyseal allograft were investigated. Chicken embryos were partially decerebrated at 36-40 hr of incubation and on day 12 received a hypophyseal allograft from 18-day-old donor embryos. The embryonic thymuses were collected on day 18 and examined with histological methods, tested for the anti-thymosti...

Conformations and catalytic rates of enzymes (biological catalysts) fluctuate over a wide range of time scales. Recent experimental and theoretical investigations demonstrated case studies where the enzymatic catalysis rate follows the Michaelis-Menten (MM) rate law despite molecular fluctuations. In this paper, we investigate deviations from MM law and their effects on the dynamical behavior o...

Block copolymers exhibit the phenomenon of microdomain formation in pure states as well as in solutions. The microdomains vest the block copolymer assemblies with the intriguing characteristics of microheterogeneous media. We demonstrate that this microheterogeneity in hydrophobic-hydrophilic block copolymer systems can be exploited for immobilizing enzymes and to carry out enzymatic reactions....

Homogenates of human platelets can mediate the synthesis of phosphatidylinositol from myoinositol and cytidine diphosphate diglyceride. The cytidine diphosphate diglyceride: myoinositol, phosphatidyl transferase activity is particulate-bound, and the highest specific activity is found in the membrane fraction. The production of phosphatidylinositol is decreased by sulfhydryl-binding agents, and...

Experiments which combined histochemistry and electron microscopy were performed in studying the sites of enzymatic hydrolysis of thiolacetic acid in the presence of lead ions in diaphragmatic and cardiac muscle. I t was found that in these striated muscles the electron opaque, final product of the histochemical reaction (PbS) was discretely deposited on the swelling of the thick elemental fila...

A commonly used enzymatic recycling assay for pyridine nucleotides has been adapted to directly measure the NAD(+)/NADH redox ratio in Drosophila melanogaster. This method is also suitable for quantification of NADP(+) and NADPH. The addition of a coupling reaction removing acetaldehyde produced from the alcohol dehydrogenase (ADH) reaction was shown to improve the linearity of NAD(H) assay. Th...

We have evaluated three analytical methods for determining inorganic phosphorus in serum applied to the Technicon RA-I000 analyzer: a fully enzymatic colorimetric method based on the specific system purine nucleoside phosphorylase/xanthine oxidase coupled to an indicator colorimetric reaction similar to the Trinder reaction; a chemical method involving the direct UV measurement of the phosphomo...

Convenient drug-resistance testing of viral mutants is indispensable to effective treatment of viral infection. We developed a novel fluorometric assay for phenotypic differentiation of drug-resistant mutants of human immunodeficiency virus-I protease (HIV-PR) which uses enzymatic and peptide-specific fluorescence (FL) reactions and high-performance liquid chromatography (HPLC) of three HIV-PR ...