Invertase covalently coupled to porous glass: preparation and characterization

The enzyme invertase has been covalently coupled to porous glass particles. The product is extremely stable over a long period of time. Kinetic values for the immobilized enzyme are similar to the native enzyme. Excellent enzymatic activity for the immobilized enzyme was exhibited over a broad pH range. The immobilized enzyme when continuously operated for one month was found to have an operational half-life of over 40 days.     

studies on aminoacylase immobilized on porous ceramic carriers

Aminoacylase was covalently coupled to several porous ceramic type carriers and studied for durability under operating conditions. These studies indicate that it should be possible to develop a commercially economic system based on ceramic carriers for the resolution of racemic mixtures of amino acids.     

Immobilized tannase

The enzyme tannase has been immobilized on an inorganic support by covalent attachment. This immobilized enzyme was characterized and half-lives determined. Since this enzyme has application in the treatment of tea cream, experiments were also carried out to determine the effect of tea on enzyme half-life.     

Heme oxygenase-1 plays a pro-life role in experimental brain stem death via nitric oxide synthase I/protein kinase G signaling at rostral ventrolateral medulla

Background  

Despite its clinical importance, a dearth of information exists on the cellular and molecular mechanisms that underpin brain stem death. A suitable neural substrate for mechanistic delineation on brain stem death resides in the rostral ventrolateral medulla (RVLM) because it is the origin of a life-and-death signal that sequentially increases (pro-life) and decreases (pro-death) to reflect the advancing central cardiovascular regulatory dysfunction during the progression towards brain stem death in critically ill patients. The present study evaluated the hypothesis that heme oxygnase-1 (HO-1) may play a pro-life role as an interposing signal between hypoxia-inducible factor-1 (HIF-1) and nitric oxide synthase I (NOS I)/protein kinase G (PKG) cascade in RVLM, which sustains central cardiovascular regulatory functions during brain stem death.     

Preparation and characterization of isolubilized L-amino acid oxidase

The enzyme L-amino acid oxidase of Crotalus adamanteus was covalently coupled to porous 96% silica glass particles. The insolubilized enzyme was active on several L-amino acids including: leucine, isoleucine, cysteine, phenylalanine, tryptophane, and methionine. No activity was observed with D-amino acids, L-asparagine, or L-proline. Maximum activity was observed at pH 7.8. Stability of the enzyme derivative was demonstrated by continuous operation of an enzyme column for 35 days, during which the bound enzyme oxidized over 5000 times its own weight of substrate.     

Insolubilized coenzymes: the covalent coupling of enzymatically active NAD to glass surfaces

NAD was attached to the surface of glass beads by a diazo coupling procedure. The insolubilized NAD was shown to function as a coenzyme in the yeast alcohol dehydrogenase reaction.